Volume 18, Number 2, June, 2010 - Noise News International

International Institute ofNoise Control Engineeringwww.i-ince.orgGilles Daigle, PresidentJoachim Scheuren, President ElectHideki Tachibana, Immediate Past PresidentRobert Bernhard, Secretary-GeneralJean Pierre Clairbois, TreasurerVice PresidentsMarion BurgessPaul DonavanSamir GergesTor KihlmanWilliam LangLuigi MaffeiGeorge MalingRajendra SinghJoseph CuschieriInstitute of Noise ControlEngineering of the USA, Inc.www.inceusa.org2009 INCE/USA OfficersJames K. Thompson, PresidentPatricia Davies, Past PresidentTeik Lim, President-ElectChristopher W. Menge, Vice President–PublicRelationsKenneth Kaliski, Vice President–Board CertificationMichael J. Lucas, Vice President–PublicationsTodd Rook, Vice President–MembershipPaul Burge, Vice President–Honors and AwardsRalph Muehleisen, Vice President - StudentActivities and EducationStephen A. Hambric, Vice President - ConferencesSteven E. Marshall, TreasurerKarl B. Washburn, SecretaryJoseph M. Cuschieri, Executive DirectorGeorge C. Maling, Jr., Managing Director, Emeritus2009 INCE/USA DirectorsJ. Stuart BoltonPaul L. BurgéPatricia DaviesPaul R. DonavanGordon L. EbbittMardi HastingsDeane B. JaegerMandy KachurRichard KolanoCharles T. MoritzRalph T. MuehleisenRobert A. PutnamThomas E. ReinhardScott D. SommerfeldtDirectorsJosef NovákSamir GergesDavid K. HolgerH. Temel BelekJing TianTrevor NightengaleNOISE/NEWSI N T E R N A T I O N A LThis PDF version of Noise/News International and its Internet supplement are publishedjointly by the International Institute of Noise Control Engineering (I-INCE) and the Instituteof Noise Control Engineering of the USA (INCE/USA). This is the first volume that is beingpublished in PDF format only. The PDF format means that the issues can be read by freelyavailable software such as that published by Adobe and others. It reduces publication time,saves printing costs, and allows links to be inserted in the document for direct access toreferences and other material. Individuals can sign up for a free subscription to NNI by goingto the web site http://www.noisenewsinternational.netI-INCEThe International Institute of Noise Control Engineering (I-INCE) is a worldwide consortiumof societies concerned with noise control and acoustics. I-INCE, chartered in Zürich,Switzerland, is the sponsor of the INTER-NOISE Series of International Congresses onNoise Control Engineering, and, with the Institute of Noise Control Engineering of the USA,publishes this quarterly magazine and its Internet supplement. I-INCE has an active programof technical initiatives, which are described in the Internet supplement to NNI. I-INCEcurrently has 46 Member Societies in 39 countries.INCE/USAThe Institute of Noise Control Engineering of the USA (INCE/USA) is a non-profitprofessional organization incorporated in Washington, D.C., USA. The primary purpose ofthe Institute is to promote engineering solutions to environmental noise problems. INCE/USA publishes the technical journal, Noise Control Engineering Journal, and, with I-INCEpublishes this quarterly magazine and its Internet supplement. INCE/USA sponsors theNOISE-CON series of national conferences on noise control engineering and the INTER-NOISE Congress when it is held in North America. INCE/USA Members are professionals inthe field of noise control engineering, and many offer consulting services in noise control. Anypersons interested in noise control may become an Associate of INCE/USA and receive boththis magazine and Noise Control Engineering Journal.NNI and its Internet Supplementwww.noisenewsinternational.netThe primary change in this PDF-only volume of NNI is the ability to have “hot links” toreferences, articles, abstracts, advertisers, and other sources of additional information. In somecases, the full URL will be given in the text. In other cases, a light blue highlight of the textwill indicate the presence of a link. At the end of each feature or department, a light blue backto toc will take the reader back to the table of contents of the issue.• The Internet supplement contains additional information that will be of interest to readers ofNNI. This includes:• The current issue of NNI available for free download• NNI archives in PDF format beginning in 2003• A searchable PDF of annual index pages• A PDF of the current NNI conference calendar and a link to conference calendars forworldwide meetings• Links to I-INCE technical activities and I-INCE Technical Reports

President’s ColumnINCE/USA: The State of the InstituteBefore I get into the State of the Institute,INCE/USA, I want to say how honoredI am to serve as the new President of theInstitute. Many years ago in my first term on theBoard of Directors, I was very impressed to meetand work with several people whom I consideredlegends in noise control. I was very humbled bythis experience, and now am amazed that I have theopportunity to lead the organization. I will do mybest, and want to acknowledge the fact that I canaccomplish nothing without support and hard workof the members of the Board of Directors and theOfficers of the Institute. INCE/USA is fortunate tohave a strong group of dedicated volunteers whowork tirelessly for the Institute and its members. Iam very proud to be a part of this team.Let me get to the true subject of this note—therecent survey I conducted to assess the State of theInstitute. We contacted 42 members and asked fortheir feedback on all aspects of INCE/USA andthe programs it conducts. The respondents werevery thorough, providing pages of comments andsuggestions in many instances. The most importantfinding from this survey was the high value placedon INCE/USA membership. The praise for theInstitute was outstanding with many citing it as themost valuable professional organization to whichthey belonged.The planning and operation of NOISE-CONconferences were cited by the majority of therespondents as the items at which INCE excels.Next to this was the praise for our Noise ControlEngineering Journal. Some of the responses notedthe improvement of this publication over the lastfew years. It was good to see the membershiprecognize outstanding performance in two of theInstitute's primary activities.There were two areas that received some negativecomments. These were the Board Certificationprogram and the Technical Activities Committees.In the case of Board Certification, a few of themembers felt this program did not provide value.One member was strongly critical of this programciting difficulties encountered in trying to gothrough the process. This is an issue which theBoard of Directors must address.With regard to the Technical Activities Committees,the primary issues were poor communicationand some questions regarding the role of thesecommittees. The Board of Directors has struggledwith these same issues for some time. The results ofthis survey emphasize the need to examine what therole of these committees should be, how to makethem a productive part of the Institute, and how tocommunicate their role to the membership.There was good feedback on the move to electronicpublications in general, seminars, marketing of theInstitute, and more communication to the membersby the President. This input presents opportunitiesto pursue to add value for the members and generategreater income for the Institute to minimize the needto increase dues or conference fees.Overall, the feedback from the survey was verypositive. The State of the Institute is great, butthere is always room for improvement. With onlya few specific issues cited, the Board and Officerscan utilize this information and make specificimprovements to the Institute and add value to ourmembers. NNIback to tocJames K. Thompson2010-2011 President2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org71

Editor’s ViewNoise and Its ControlMarion BurgessAsia Pacific EditorIt is particularly relevant to have a report in thisissue from a symposium in Ottawa assessingvarious kinds of noise control technologies. Thehigh number of papers at 2010 INTER-NOISECongress held in Lisbon in June highlights theneed for the application of noise control technologyaround the world. The CAETS (InternationalCouncil of Academies of Engineering and TechnicalSciences) forum held during the congress andorganized by Tor Kihlman and Bill Lang, focusedon worldwide noise sources. The report will beproduced in due course but the forum providedanother opportunity for discussions on the actionsby governments and authorities that are necessary toensure that noise control technology is applied.While there is a good international agreement ondamage risk levels, the challenge for regulatoryauthorities is to establish what levels of noise areacceptable for those in the community who areannoyed by noise. Noise control technologies areavailable for application to the majority of noisesources in the working environment which couldreduce the extent of noise induced hearing loss aswell as reducing the reliance on personal hearingprotectors. Enforcement of noise exposure limitsas well as information on noise control measuresavailable can work together to achieve a quieterwork environment.The challenge is somewhat greater in relation toachieving an acceptable noise level in the communityespecially in residential areas. The subjective reactionto noise must be taken into consideration whenestablishing criteria or guidelines. This inevitablyleads to the need for flexibility, and an understandingof the social context, in the establishment of suchlimits by the regulatory authority. Two exampleshighlight this need. In the days before the INTER-NOISE Congress, a festival in Lisbon led tocelebrations throughout the night. This was clearlya special activity with widespread support in thecommunity. The entire community was involved withthe celebration and clearly enjoyed the associated“noise,” and any attempts to apply noise controltechnology would not be welcomed. In contrast thenoise from an outdoor concert may enjoyed greatlyby those attending but the surrounding communitymay be justified in seeking application of noisecontrol technology to reduce the noise impact forthose not involved in the entertainment activity.For many noise sources in the environment there arecontrol technologies available that can be appliedbut may not be used until there is some enforcementby the regulatory authority. However managingnoise in the environment needs an understandingthat the reactions to noise include factors beyond thequantifiable or measurable noise levels. NNI72 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

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Member Society ProfileThe Swedish Acoustical SocietySvenska Akustiska Sallskapet orthe Swedish Acoustical Society(SAS) was established in 1945.The current president of the society isHans Jonasson, SP Technical ResearchInstitute of Sweden, Borås. SAS publishesa journal, LjudBladet, three times a year.The journal includes acoustical newsfrom Sweden but also papers of generalinterest. SAS also runs a web page,www.akustiska-sallskapet.org. Eachyear the board of SAS awards a prize,Ljudpriset, to an individual or anorganization that has made significantcontributions to promote a better acousticenvironment. SAS encompasses all areasof acoustics. However, for vibration thereis another society, SVIB.SAS sponsors acoustical meetings allover Sweden. One meeting is the annualmeeting of SAS and it includes severalacoustical lectures. The location ofthis annual meeting varies from yearto year. The last three years it has beenin Gothenburg, Stockholm and Lundrespectively. The 2009 Ljudpriset wasawarded to the real-estate companyAnders Bodin Fastigheter AB forpioneering work in building dwellingswith very high sound quality. Thecompany was first in Sweden to buildwith sound class A, which is two classesbetter than required by the nationalbuilding regulations. For sound insulationthis means 8 dB better. This is aninteresting development. Thirty yearsago all dwellings were built accordingto government building regulations,which, at that time, were considered tobe adequate. Today, when many elderlypeople sell their one-family house in thesuburbs to move to expensive apartmentsin downtown areas they expect and requirea higher acoustical standard.SAS is a member of the EuropeanAcoustics Association, EAA, theNordic Acoustic Association, NAA, theInternational INCE and ICA. In 1990, SAShosted INTER-NOISE 90 at ChalmersUniversity of Technology in Gothenburg.The number of registered delegates at thatcongress exceeded 800 with participantscoming from 39 countries. At INTER-NOISE 2010, 42 of the registeredparticipants came from Sweden. Membersof NAA are the five acoustical societiesfrom Sweden, Denmark, Finland, Norwayand Iceland. Iceland has the youngestsociety which joined NAA in 2006. Thesocieties take turns hosting the NordicAcoustical Meetings held every twoyears, which, the last few times, havebeen named Baltic Nordic AcousticalMeetings (BNAM) in order to encourageparticipation from the three neighboringBaltic countries. Many acousticiansfrom Estonia are members of the FinnishAcoustical Society but otherwise ourBaltic colleagues are not yet organized innational societies. The last time Swedenhosted this meeting was in Gothenburgin 2006. In 2008, it was in Reykjavik,Iceland, and 2010 in Bergen, Norway. Thenext meeting will be in Odense, Denmark.Because of the Baltic association BNAMis now held in English instead of in theScandinavian languages so it is now also ofinterest to non-Scandinavian acousticians.From 2011 a subscription with on-lineaccess to the European journal ACTAACUSTICA will be included in themembership fee .NNIThis is the 72nd in a series of articles onthe Member Societies of InternationalINCE. This is an update of the profile thatappeared in the 2001 September issue ofthis magazine.—Ed.Member Society Profile is a regularfeature of Noise News International.If you would like to have yoursociety featured, please contactGeorge Maling at inceusa@aol.com.74 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

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INTER-NOISE 2011 ANNOUNCEMENTDear Colleagues,INTER-NOISE 2011, the 40th International Congressand Exposition on Noise Control Engineering, will beheld in Osaka, Japan From 2011 September 4 throughSeptember 7. The Congress is sponsored by theInternational Institute of Noise Control Engineering(I-INCE) and co-organized by the Institute of NoiseControl Engineering Japan (INCE/J) and the AcousticalSociety of Japan (ASJ). The organizers and theOrganizing Committee of the Congress extend a warmwelcome to all prospective participants world-wideand invite all to join us in Osaka to discuss the latestadvances in noise and vibration control engineeringand technology, focusing on our Congress Theme of“Sound Environment as a Global Issue.”INTER-NOISE 2011 will feature a broad range ofinvited and contributed papers, together with plenarylectures by distinguished speakers. There will beextensive exhibitions of noise and vibration controltechnology, measuring instruments, equipment andsystems from all over the world. Technical papers onthe congress theme will be accepted with a specialacknowledgement. Research papers in all other fieldsof noise and vibration are welcome.INTER-NOISE 2011 will be held at the OsakaInternational Convention Center (Grand Cube Osaka),directly connected to the Rihga Royal Hotel and easilyaccessible for international flights. Grand Cube Osakais located close to the city centre of Osaka, which isthe second largest city in Japan and is the center ofIchiro Yamada, Congress Presidentcommerce, culture, food, etc in the Kansai Area withmany historical sites such as Osaka Castle. It is our pleasure to welcome you to INTER-NOISE 2011 and Osaka. We aresure you will enjoy all aspects of the Congress and Osaka. We look forward to meeting you in Osaka.Sincerely,Ichiro Yamada, Congress PresidentOn behalf of the INTER-NOISE 2011 Congress Organizing Committee76 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

First AnnouncementThe 27th annual conference of theInstitute of Noise Control Engineeringof the USA, NOISE-CON 2011, will runconcurrently with the summer meetingof the Transportation Research Board,Committee on Transportation-RelatedNoise and Vibration (ADC40) on Mondaythrough Wednesday (25-27 July, 2011).This conference is joining theoverlapping transportation noiseand vibration interest of thetwo organizations in Portland,Oregon to take advantageof the strong public interestand readily accessible publictransportation project sitescurrently found in the PacificNorthwest.The technical program for thejoint conference will providean opportunity for publicand private organizations toshare technical informationon noise and vibration topicsassociated with high speed rail,light rail systems, highwaysurface and tire noise andaircraft noise to name a few.In addition, the technicalprogram will include papers inareas such as Experience withMeasuring and Modeling ofWind Turbine Noise, Controlof Noise Both Interior andExterior to Buildings, Industrial NoiseMeasurement and Control, ProductNoise Measurement and Control, NoiseMeasurement Equipment and Techniques,Structural Noise Transmission and Controland Community Noise Measurement andControl.Kerrie Standlee of Daly-Standlee &Associates, Inc. in Beaverton, Oregonwill be the General Chair for the meeting.Hugh Saurenman of ATS Consulting inLos Angeles, California and Paul Donavanof Illingworth & Rodkin, Inc. in Petaluma,California will be the Technical Co-Chairsfor the meeting.An exposition of vendors ofnoise-control related materials,instrumentation and softwarecompanies will commence onMonday evening with a receptionsponsored by the vendors andend on Wednesday morning atnoon. A social gathering forattendees will occur at an offsitelocation to include specialactivities for conference membersas well as family guests. A specialaccompanying guest program willalso be included as part of theconference to encourage attendeesto bring their families and considerthe Portland conference as thebeginning of wonderful vacationlocation.Finally, NOISE-CON 2011 willcelebrate the 40th Anniversary ofINCE-USA by holding a specialevent to recognize the foundingorganizers and past presidents ofthe organization.NNI2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org77

NOISE-CON 2010 Report:A Joint ASA and INCE/USA ConferenceBaltimore, Maryland was the venue forNOISE-CON 2010, the 24th conferenceof the Institute of Noise ControlEngineering. The first NOISE-CON washeld in 1973. The meeting took place onApril 19-21, 2010 the Marriott WaterfrontHotel, and it was held in conjunctionwith the 159th meeting of the AcousticalSociety of America (ASA). This wasthe fourth meeting held in conjunctionwith ASA. The first was held in 1997 atthe Pennsylvania State University. Thesecond was held in 2000 in NewportBeach, California, and the third was heldin 2005 in Minneapolis, Minnesota. Forthis meeting, Mardi Hastings of GeorgiaTech served as the chairman of the ASAmeeting, and Michael Lucas of Ingersoll-Rand served as the general chair forNOISE-CON. Courtney Burroughs, editorof Noise Control Engineering Journaledited the conference proceedings. Twohundred and ninety eight papers appearon the CD. Richard Peppin was theexposition manager, and arranged for51 booths to be filled at the conference.The exhibition opened on Mondayevening, April 19, and closed in theafternoon Wednesday, April 21. The list ofexhibitors is available as a link from thispage.Mike Lucasw and Mardi Hastings are happy that the joint meeting was a success.Kenneth J. PlotkinSince registration for the meeting wasdone by the Acoustical Society, and allregistrants were welcome to attend bothNOISE-CON and ASA sessions, it is notpossible to determine the NOISE-CONonly registration. However, approximately2000 persons attended the joint meeting.18 sessions were labeled as NOISE-CON only, and another 15 sessions wereLilly M. WangTodd E. Rook78 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

organized jointly with INCE/USA and oneor more ASA technical committees.The first plenary session took place onMonday morning and was a presentationby Kenneth J. Plotkin of Wylelaboratories. The title of his talk wasSonic boom: from bang to puff. AbstractThe second plenary session of NOISE-CON conference featured a paper by ToddE. Rook of the Goodrich Corporation. Thetitle of this paper was Noise and vibrationphenomena in aircraft wheel and brakesystems. AbstractOn Tuesday evening, all attendees at thejoint meeting were treated to a buffetdinner in the hotel as part of the regularASA social program.Alan Marsh, right, receives the DNCEaward from (now) INCE/USA presidentJames K. Thompson.Eric Baugh, left, and Jessica Gullbrandare recognized as recipients of theHirschorn prize.The third plenary session was held onWednesday morning and featured a papertitled Effects of building mechanicalsystem noise on the worker performanceand perception by Lilly M. Wang ofthe University of Nebraska—Lincoln.AbstractA joint awards ceremony was heldin the afternoon of April 21. Alan H.Marsh was presented with the INCE/USA Distinguished Noise ControlEngineer award. The INCE DistinguishedNoise Control Engineer award (DNCE)recognizes individuals who have renderedconspicuous and consistently outstandingservice to the Institute and to the field ofnoise control engineering over a sustainedperiod. Alan Marsh was cited …forpioneering contributions to aircraft noisereduction, efforts to improve technicalstandards for sound level meters and forsustained service to INCE/USA. The firstgroup of INCE/USA fellows was alsorecognized at the awards ceremony. Moreinformation can be found on the Internatat http://www.inceusa.org/fellows.aspJiri TichyIn addition, Mark A. MacDonald, JessicaGullbrand, Yoshifumi Nishi, and EricBaugh, INTEL Corp. were recognized asthe winners of the 2010 Martin HirschornIAC Prize Best Paper Award of 5000USD which was funded by the INCEFoundation. The award was for the bestpaper on new and/or improved costeffectivenoise control and/or acousticalconditioning products published in thetwo years preceding the award. The paperKent L. Geeappeared in Noise Control EngineeringJournal, 57(4), 348-359, 2009, and wastitled Notebook blower inlet flow andacoustics: Experiments and simulations.A student paper competition was held inconjunction with NOISE-CON 10. Fivestudents were awarded prizes of 1000USD each which were funded by theINCE Foundation. The winners and theirpaper titles were:2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org79

Joseph Corcoran, Virginia Tech, USAOutput-only modal testing of simpleresidential structures and acousticcavities using the response to simulatedsonic booms and ambient excitationTyler Dare, Purdue University, USANoise generation in contraction joints inPortland cement concreteJie Duan, University of Cincinnati, USAA novel delayless frequency domainfiltered-x least mean square algorithm forvehicle powertrain noise controlWenwei Jiang, University of Cincinnati,USATwo-substructure, Time-Domain TransferPath Analysis of Transient DynamicResponse of Mechanical Systems withNonlinear CouplingLogesh Kumar Natarajan, Wayne StateUniversity, USAEnhancing accuracy in reconstructionof vibro-acoustic responses of a complexstructure using Helmholtz equationleast squares based nearfield acousticholographyAcoustical Society of America awardswere also presented during the ceremony.Two major awards were presentedto individuals with connections toINCE/USA. Jiri Tichy, 1987 INCE/USA president, was presented with theSociety’s highest honor, the Gold Medal.Left to right, Student winners Wenwei Jiang, Jie Duan, and Tyler Dare with (now INCE/USA president James K. Thompson and Ralph Mueheisen, vice president for studentactivities and education.He was cited …for contributions toacoustic intensity measurement, activenoise control, education in acoustics, andfor service to the Society. Kent L. Geereceived the R. Bruce Lindsay Award.The award is given to a member of theSociety who is under 35 years of age onJanuary 1 of the year of the award andwho, during a period of two or more yearspreceding the award has been active in theaffairs of the Society and has contributedsubstantially, through published papers,to the advancement of theoretical orapplied acoustics, or both. He was cited …for contributions to the fields of jet noisepropagation, nonlinear acoustics, andactive control of fan noise. In 2004, Kentshared the 5000 USD Martin HirschornIAC Prize with Scott Sommerfeldt fortheir paper A compact active controlimplementation for axial cooling fan noisewhich was published in Noise ControlEngineering Journal. In 2002, he wonan INCE/USA student paper prize forclosely-related work.A CD of the papers presented at NOISE-CON was also available at the conference.In addition to the 298 NOISE-CON 2010papers, the CD also contains the papersfrom NOISE-CON 07 and NOISE-CON08. More information on ordering copiesof the CD can be found on the final pageof this issue. Link80 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

Worldwide Noise SourcesJanet Moss, Noise Control Foundation, Poughkeepsie, NY 12603IntroductionA forum titled Worldwide Noise Sourceswas held in conjunction with INTER-NOISE 09 in Ottawa, Canada on 2009August 24-26. The Ottawa forum was afollow-up to the 2008 June workshop onthe design of low-noise vehicles for air,road, and rail transportation that was heldat the Institute of Sound and VibrationResearch, Southampton, U.K. in June,2008. The report from that forum waspublished in the 2010 March issue ofthis magazine. This forum considerednon-vehicular noise sources that presentworldwide problems and will assess thestate of noise control technology today.Noise emission goals for the future thatwill support sustainable development arerecommended.The purpose of the forum was toidentify and prepare an inventory of thetechnology available today for the designof low-noise products and equipment andto assess what is needed to be developedin future technology for the reduction ofnoise emissions of these products andequipment. This technology assessmentwill provide the the InternationalCouncil of Academies of Engineeringand Technical Sciences (CAETS) withan update on the state of noise controltechnology so that CAETS may supportrecommendations to be developed by theCAETS Noise Study Committee on thenoise issue. (See the President’s Columnin the March issue of this magazine.—Ed.)These recommendations will encouragethe use of low-noise noise vehicles,machinery, and other products andpromote their use throughout the world.This forum considered non-vehicularnoise sources in occupational,domestic, and community settings andconcluded with a roundtable to discussrecommendations on control of worldwidenoise sources for a statement to becirculated to policy-makers by CAETS.The forum ran in parallel with thetechnical sessions of INTER-NOISE 2009following the morning plenary sessions.Low Noise Machinery andLow-Noise ProductsThe first session was devoted to low-noisemachinery and equipment for workplaceand community. This session was devotedto the design of products, machinery, andequipment that are sources of noise inoccupational, domestic, and communitysettings. Included were the “basic”mechanical components (engines, pumps,fans, compressors…) and a “green”source of power.The second session was devoted to lownoiseproducts. During this session thefocus was on the design of low-noiseproducts and equipment (stationaryproduction equipment in manufacturingplants, consumer products and householdappliances, off-road recreational vehicles,and office equipment).Session 1 and 2 PanelistQuestions1. For your product how important isthe low-noise criterion compared tothe other performance criteria such asrobustness, energy efficiency, design,and price?2. What is the extra cost (percentageof the cost) to produce a low-noiseproduct versus a product where noiseis not a consideration?3. Where do the requirements forlow-noise products come from(regulations, management,purchasers, end-users, or othermanufacturers integrating theproducts)?4. How are relations managed betweenthe manufacturers of noise-generatingcomponents (motor, compressor,engine, muffler, damper…) and themanufacturers of complex machinesintegrating them?5. How many people are involved innoise research and development inyour company (for measurement,design, prototyping, control…)? Isthis work subcontracted to consultingfirms, research and developmentinstitutions, or universities?6. What test facilities are used in thedesign of your company’s product(specific test rigs to ‘load’ themachine, acoustic rooms…)?7. What tools and software are used fornoise measurement and analysis?8. Is the concept of ‘subjective soundquality’ a concern for the productyour company produces? If theanswer is affirmative, which metricsdo you use?9. If you perform measurements ofcompetitive products, how do yourcompany’s products rank?10. Are noise measurements performedin your company’s production controlprocess?11. During your product developmentprocess do you study noisegeneratingmechanisms and/or thephysics of sound transmission andradiation?2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org81

12. Do you characterize the noiseemissions (airborne, structureborne,or fluidborne sound) of themechanical/electrical componentsthat your company manufactures orthat are integrated into its products?How is this done?13. Do you characterize the performancesof any noise-attenuating devices(isolators, mufflers, silencers,enclosures, cabins…) that areintegrated into the company’sproducts? How is this done?14. What tools are used to identify soundsources and analyze sound paths andtheir control?15. During the paper phase of the design ofthe product, what tools and software doyou use and do they integrate vibrationand acoustics predictions?16. Do you use specific tools andsoftware for noise prototyping?17. Is the metric currently used todescribe the outdoor noise emissionof your product an adequaterepresentation of the low frequenciesradiated to adjacent buildings?18. Is the noise emitted by the powersource for your product a significantcontributor to the overall noiseemission of the product?19. Is retrofitting in situ to reduce thenoise of older equipment that has anadditional effective lifespan a feasibleoption for manufacturing plants?20. What information does the purchaserof low-noise home appliances need?Are the metrics currently used todescribe the noise emissions of theseproducts satisfactory?21. Is the engine the principal noise sourceof off-road recreational vehicles(motorcycles, snowmobiles, all-terrainvehicles, jet skis, pleasure watercraft,and ultra-light or micro-light aircraft)?What are the principal sources of equipmentnoise in offices and the means to reducetheir noise emissions at the source?Building NoiseThe focus of this session, Session 3, wason the design of buildings (including“green” buildings) and the constructionproducts and materials developedto provide low-noise environments.Recommended practices and buildingcodes were considered.Session 3 Panelist QuestionsWhat advances have been made inthe technical understanding of soundtransmission in buildings in recentdecades? What major technical challengesimpede systematic and correct predictionof the sound reaching building occupantsfrom specific sources?1. What elements are neededto implement the scientificunderstanding of sound transmissionin the systematic design andevaluation of buildings to meetoccupant requirements? (such astechnical standards for measuringperformance of the building,standards for evaluation of subsystemperformance, methods to integratedata on subsystem performance,credible information sources).2. What is needed for an effectiveregulatory system for the acousticalperformance of buildings? Are theregaps in the available measurementstandards or the subjective criteria onwhich to base regulations?3. How are building codes enforced(in Europe, in North America,elsewhere)? What barriers impedea common international approach?(harmonized technical standards,common performance criteria,historic concerns, etc.)4. What advances in a system approachhave been made to minimize thenoise of equipment in commercialbuildings and homes? Howdo differences between heavyand lightweight construction(concrete and masonry versuslightweight framed systems) affectsuch transmission? Are separateapproaches needed for buildingservices (plumbing, HVAC, etc.) andfor occupants’ appliances such asdishwashers?5. How can the noise generated bymachinery and equipment within abuilding be controlled by a buildingcode or other regulations? Areenhanced technical standards needed?(source emission versus noiseat receiver and related gaps inknowledge and tools)6. What special issues create theneed for extensions beyond theconventional approach to soundinsulation based on average soundpower reaching a space.(speech security, low-frequencyissues, etc.)7. As low-frequency noise andvibration from arterial traffic must beminimized in adjacent commercialbuildings and homes, what specialnoise and vibration control treatmentshave been found to be most effective?8. What are the advantages anddisadvantages of a “green” buildingdesign framework in providing asatisfactory acoustical environmentfor the occupants?9. What new advances for noise controlin buildings are anticipated duringthe next decade?Codes, Practices, andStandards for Low-NoiseMachinery and EquipmentThis session, session 4, addressedrecommended practices, labeling, noisedeclarations and requirements, and thelimitations of current standards as wellas future needs for standardization,test codes for products, machinery, andequipment.Session 4 Panelist Questions1. How can international test standardsbe more “user friendly”?Background for question – There is a82 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

2.growing concern that it takes a Ph.D.in acoustics to not only understandthe test code, but also to be able toapply it. The standards producedby ISO Technical Committee 43(acoustics) and its Subcommittee1 (noise) are complex and manyof them require advanced formaltraining in acoustics to understandand implement. The standardsproduced by TC 43/SC 1/WorkingGroup 28 (Basic Machinery NoiseEmission Standards are goodexamples. An untrained personwould have great difficulty in makingmeasurements according to theInternational Standards prepared byWorking Group 28.How can we involve consumersand the public in the ISO and IECstandards development process?Background for question –Involvement will ensure that publicinterests are being considered. Thereare many reasons these standardsare so complex, but perhaps aprincipal reason is the ISO/IECstandards development process itself.Financial support to participateand attend meetings comes fromindustry and government agencies.The developers of the standards areacademics, government employees,manufacturers' representatives, andconsultants; but the public is notrepresented in the ISO developmentprocess. By contrast, the AmericanNational Standards Institute(ANSI) encourages participationof representatives of the publicon standards working groups bypermitting their comments on draftstandards with the requirementthat those comments be addressed.ANSI S-committees on acousticsand noise administered by theAcoustical Society of America have acategory of membership representingconsumers, i.e., the public. In the ISOdevelopment process, internationalstandards are produced for measuring3.4.5.sound levels to a small fractionof a decibel while many electedrepresentatives of the public wholegislate regulations have difficultydeciding on required sound levels tothe nearest 5 or 10 decibels. This willnot be easy to correct.How do we ensure that manufacturersdo not “cheat” on or misrepresent thenoise declarations of their products?Background for question – There areseveral possible ways to correct thissituation:a. Apply the correct “K” factor (toaccount for product variability,measurement method variability, andmanufacturer’s risk).b. Certify by an independentauthority that the tests wereconducted according to the relevantstandard (for example, not testingat temperatures less than the lowerend of a standardized temperaturerange for a product with fan speedcontrol or not measuring emissionsound pressure level at “bystanderpositions” instead of a nearbyoperator position).[Alternate question] Is there evidencethat some manufacturers havemisrepresented the noise declarationsof their products? If so, how can weensure that manufacturers do not“cheat” on their noise declarations?How can we ensure that teststandards enable or encouragethe application of technologywithout ambiguity and do not stifleinnovation by acting as barriers to theimplementation of technology?Background for question – Somecurrent International Standardsconflict with one another in theirdescriptions of operating proceduresand test conditions for similar noisesources. The International Standardsneed to be revised to clarify theuse and applicability of individualstandards.What new measurement standards areneeded? What current measurement6.7.8.standards need major revision toimprove their usability?Background for question – Themeasurement standards for someindustries are highly developed andupdated in a timely fashion (e.g.,information technology industry),but the standards for the products ofmany industries are at an early stageof development.How do we handle the confusion ofconsumers between sound powerlevel and sound pressure level andthe even more confusing use of thedecibel as the unit of measure forboth sound power level and soundpressure level?Background for question – Thisconfusion has been known anddiscussed for decades. Theinformation technology industry hasadopted a simple solution to thisproblem, but other industries havefailed to follow suit.In terms of product noise declarations(labels, tags, on-line information),actual numbers are important anduseful for characterizing the noiseemission levels, but how can webest get “comparative” noise-levelinformation presented to a consumeron how one product compares toother products in the same family?Background for question – Thisquestion raises supplementaryquestions:a. How can independent authoritiescollect or “certify” the “range oflevels for similar products” thatwould be necessary for such acomparative noise declaration?b. Anticipating that establishing suchrange-of-levels for the many producttypes and sub-types will take years,how can we best present comparativeinformation in the interim forproducts that lack established ranges?With respect to product noisedeclarations what about products thatare loud enough that an additionalconcern (and perhaps the only2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org83

concern) is as a “Noise Hazard” withthe potential for hearing damage?Background for question – Thisquestion raises supplementaryquestions:a.What kind of safeguards would beeffective? Warnings? Labels? NoiseHazard Symbols? Information tolower risk?b.What can a manufacturer do to bestcommunicate these safeguards to thepublic or prospective purchaser?c.Should a product noise declarationwith “Noise Hazard” information bedifferent from the normal productnoise declaration for productswithout risk for potential hearingdamage? In what ways should thedeclaration be different?SESSION 1: LownoiseMachineryand Equipmentfor Workplace andCommunityPanelists• Jean Tourret, France, Session ChairOverview of the machinery andequipment noise issue• Raj Singh, Ohio State University,U.S.A.Design of low-noise mechanicalcomponents• Steve Marshall, Baltimore Air Coil,U.S.A.Challenges in the design of low-noiserefrigeration compressors• Marco Beltman, Intel, U.S.A.Design of low-noise fans and airmovingdevices• Serguei Timushev, Moscow, RussiaCFD programs for pumps and fans,acoustic optimization• Michael Dittrich, TNO (presentedby Frits van der Eerden, TNO) TheNetherlandsLow-noise design of complex machinesusing specific software• Mark Bastasch, CH2M Hill, U.S.A.Design of wind turbines and farmsPresentationsJean Tourret – Overview ofthe machinery and equipmentnoise IssueThis overview is from the perspective ofthe French Mechanical Industries (about7000 companies that are diverse in sizeand products) which represent a widespectrum of problems to be solved inmany domains of industrial noise andvibration control.These companies are confronted bytwo main types of noise and vibrationproblems:• Designing and manufacturing betterproducts in terms of low noise andvibration performance.• Reducing noise and vibration ofproduction tools for workers, machinesand environment.Most of the effort (> 90 percent in terms ofmoney) is concentrated on the first issue.This is due to the current economic impactof low-noise products in Europe, enforcedby new regulations and strong competition.Designing and ManufacturingBetter ProductsA product which is noisier than itscompetition will not find a market! Asurvey of products manufactured by themechanical industries has shown thatapproximately 50 percent of those havenoise and vibration issues. Those productscan be classified in three main categoriesfor which different strategies apply:"active" mechanical components;machines, appliances, and equipment; andmobile machines and vehicles“Active” ComponentsThese include gears, mechanicaltransmissions, hydrostatic transmissionsand actuators, hydraulic pumps andvalves, air compressors, refrigeratingcompressors, fans, air moving devices,internal-combustion engines, and electricmotors.There are generally no regulationsconcerning the noise emissionof components but there may bespecifications given by “integrators” tosuppliers.The manufacturer may have to providespecific vibro-acoustic data: vibrationlevels at key points, pressure pulsationsin pipes or ducts, and sound pressurelevels/sound power levels. These data aremeasured under load on a classical test rigused for the tests of the product or on asound–proofed rig in order to reduce theeffect of extraneous sources. Dependingon the production volume, measurementsare systematic or very limited and areperformed by the control laboratory.If the manufacturer decides to improve theproduct or develop a “silent” one, the taskneeds strong involvement of the designoffice. Advanced studies on the noisegenerated by components needs a detailedknowledge of machines, mechanics,and fluid mechanics which has a higherpriority than knowledge in noise andvibrationMachines, Appliances andEquipmentThese represent a diversity of productssuch as portable electric tools, computers,medical devices, domestic appliances(washing machines, refrigerators), boilers,air handling units, machine tools, textileor printing machines, food processing,packaging, chemical processing, andpower units. Many of these machinesare covered by standards or regulationsconcerning their sound emissions to theusers or to the environment.84 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

Noise “labelling” puts commercialpressure on several types of products tobecome quieter and the manufacturershave to provide information about thenoise emissions of their products.Sound measurements based on specifictest codes have to be performed undercontrolled conditions in terms of loador acoustical environment (anechoic orreverberant rooms for small machines, freefield or sound intensity for large units).Noise and vibration are generated eitherby the “active” components (and thenfrequently amplified by the structureof the machine) or by the process itself(cutting, grinding, flow).Reducing noise and vibration requires abroad knowledge: process(es) involved,vibroacoustic performances of ”active”components (seen as black boxesgenerally), structural dynamics and rotordynamics, general tools for vibrationand acoustic analysis and modelling,systems and materials for noise control(intake, exhaust, and ventilating silencers,enclosures, vibration isolators, damping,and absorbing systems). The manufacturerhas to permanently improve the vibroacousticperformances but the effortdepends a lot on the type of application(for example, HVAC machines andhome appliances are considered as more“sensitive” than machine tools.)Mobile Machines and VehiclesThis covers agricultural tractors andmachines, earth-moving machines,handling trucks, cranes, and also transportvehicles like rail-vehicles, ships, lightand heavy trucks, and busses. Thenoise issue concerns both the noiseproduced outdoors and the acousticcomfort inside the vehicle for the driverand the passengers. For outdoor noise,strict regulations exist (such as in theoutdoor machinery European Directive)that require information on soundemissions and impose limits. Rathercomplex measurements are performedin many cases by official laboratoriesbut manufacturers have to check inadvance the result which may needcostly installations and tests. For internalnoise, measurements are performed atthe working position in the cabin (at theoperator’s ear using classical methods),and at the passenger position in transportvehicles.The noise is generated primarily by thepower-train system but also, for vehicles,by the rolling process which is stronglydependent on the rail or road surface.Reducing noise and vibration needs aextensive knowledge of the primarysources (engine, gearbox, hydrostatictransmissions, cooling fans), thesecondary sources (air conditioning,rolling noise, aerodynamic noise), andmufflers, ventilating silencers, enclosures,encapsulation, vibration isolators,damping and absorbing materials andinclude active control, vibro-acousticalanalysis and modelling, and sound qualitytechniques.For the three categories of products,manufacturers cope with noise problemsin very different ways. In many situationsthey partly or totally subcontract the R&Dto a specialized consulting company or doit in association with a university. Only asmall number of manufacturers (specificunits of large companies or some largeSingle Market Enterprises) can handleby themselves the development in noisecontrol and have their own dedicated labsand equipment.Reducing Noise andVibrations of the ProductionToolThis includes two main objectives:Reducing noise and vibrations for theoperators inside workshops, and reducingnoise and vibrations outside the factoryfor the neighboring environment.Reducing Noise for theOperators Inside Workshopsor FactoriesThis activity has increased significantlyover the last 30 years. It has now becomea major objective for production factoriesand plants under the pressure of relevantEuropean directives which impose noiselimits at the work station.In the mechanical industries mostmanufacturing processes and machinesare involved: forging, forming, grinding,sheet metal working, punch presses,lathes, and high speed mills.The situation is similar in most otherindustrial sectors like woodworking,plastic working, food processing, as wellas in the building construction sector.The most efficient way to reduce noise isto do so as close to the source as possible.The more “elegant” way consists inimproving the process or in replacing themachine with a more silent one whichis quite uncommon. The more classicaland efficient alternative is to use total orpartial enclosures with efficient vibroisolationand silent ventilation. Anotheralternative is to introduce sound absorbingceilings and walls together with absorbingscreens. The last alternative is to useindividual hearing protectors.Reducing Noise for theNeighboring EnvironmentOutside the FactoryThis has now become a significantobjective for production factories andplants under the pressure of relevantEuropean directives which impose noiselimits in the environment. The noiseoutside the building is reduced by noisecontrol measures inside but it can befurther reduced by using highly-isolatedwall panels and doors and by controllingseparately the émission of outside sources.Prediction tools exist to optimise thesound insulation of the building.The means dedicated to reducing thenoise of production tools are generallylimited financially. With the exceptionof very large companies there is usually2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org85

no specific staff to handle the problemof noise reduction inside or outsideof the factory. The problem is thensubcontracted to an acoustic consultantas well as to a manufacturer of enclosuresand silencers or to a building contractorand to suppliers of specialised absorbingor insulating materials. In many situationsthis activity is supervised by the safetyand health department or by the buildingmaintenance and construction departmentof the company in which one of thestaff has been trained at an elementarylevel on acoustical measurements, soundpropagation, and building acoustics.It is not uncommon in medium-sizedcompanies to have a sound-level meter forcontrol purposes.Raj Singh – Design of lownoisemechanical componentsIntroductionNoise from machinery, equipment,products, and vehicle componentscomes from a collection of machineelements, mechanisms, and actuators,including gears, brakes, belts, bearings,clutches, etc. Many common physicalcharacteristics lead to vibration sources,including multiple periodicities andmodulations. Source strengths are alsostrongly influenced by key non-linearcharacteristics such as clearances, dryfriction, multi-valued springs, etc.Common Machinery NoiseSource FeaturesTo begin identification of sources(with focus on vibration sources), oneshould identify frequencies or periodsbased on kinematics; also, relate peaks/impulses and periods to physical eventsor processes. Then, conduct force andmotion analyses on the dynamics ofmachine elements. Further, examinemulti-dimensional motion coupling,vibration modes and resonances,dynamic interactions between machineelements, and mobilities of sub-systems.Typical excitations of periodic forces/torques include rotating and reciprocityunbalance, misalignments, eccentricities,pulsating pressures, torques, electromagneticforces, etc., vortex shedding,passage/contact frequencies, unstableoperations, etc. Typical excitations ofperiodic motion sources include harmonicdrives and linkages, deviation fromkinematic conjugacy (gears, splines),surface waviness and finish, eccentricities,eccentric cams, out of roundness, etc., andmotion from other components.Side-band StructuresAs an example, consider spectralmodulations or side-band structuresthat are commonly found in rotatingsystems (such as gears, bearings, fans,tires, motors, etc.). Modulated spectralcontents are of importance fromnoise and vibration control and healthmonitoring (fault detection) perspective.Modulations affect perception metricswhen monitoring sound quality. Theexistence of frequencies can be explainedby several theories (Kinematic, Fourier,Communication) but the amplitudebehavior including an asymmetric nature(or disappearance) of some side-bands isnot well understood. The force modulationconcept and dual-domain periodic,non-linear differential equation seem tooffer better explanations. New or refinedactive control of multi-spectral contents,should one engage in the suppression ofamplitude or frequency modulated typesignals?Noise Source Analysis UsingLinear System Theory andSome ComplicationsFrequency response functions (based onthe linear system theory) are often usedto examine vibro-acoustic issues in thefrequency domain (ω). Conceptually,the single input and single outputrelationship, as given by X(ω) = H(ω)F(ω), is the simplest model; here, F(ω) isthe excitation in frequency domain, andf(t) is the excitation in time domain; X(ω)is the vibro-acoustic response, and H(ω)is the transfer function from source toreceiver. Complications include the factthat many internal sources (inputs) existand interact with each other, and sourceregime(s) include amplification elements(such as resonances). Also, source spectraare modulated. Deviation from the linearsystem theory would bring in non-linearelements (dry friction, clearances) andtime-varying parameters (such as springand damping). Lastly, sources interactwith structure-borne paths.Some Non-Linear Vibrationand Noise SourcesAmong non-linear vibration and noisesources are clearance, dry friction, slidingfriction in gears, and multi-valued springs/dampers. Clearances can be found intorsional geared systems, belts, bearings,etc. Clearances generate rattle or clunktype noise problems. Dry friction affectsbrakes, driveline systems, belts, etc.,which can lead to stick-slip inducedvibration, noise, and instability. Slidingfriction in gears is also a source of gearnoise. Multi-valued springs/dampers,which include fluid mounts, actuators, andactive materials, can experience amplitudeand frequency-dependent stiffness ordamping. Many noise and vibrationsource regimes are also defined by nonlinear,time/spatially-varying differentialequations. As an example, brake groan(stick-slip) events follow a set of nonlineardynamic regimes corresponding toseveral stick-slip frequencies of frictioncoupled systems.Reduction of Machinery NoiseSourcesThe generic principles of the reductionof noise sources include two keyfactors: steady state noise and transientsand vibro-impacts. To reduce steadystate noise, reduce source strengthsby balancing parts, minimizingmisalignments and eccentricities, etc.Also, choose relatively quieter elements.Improving contact regimes to reducedynamic loads and providing properlubrication will help reduce frictioninducedsources. Avoid resonanceswhere possible, and (changes in natural86 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

frequencies; reduce coupling) usestructure-borne path control methods(isolators, damping, absorbers, mobilitymismatch, etc.) without changing thesources. In reducing transients and vibroimpacts,make certain to avoid impulsiveexcitations or sharp discontinuities byadding preloads or incorporating systemelements that reduce impulsive loads.Typically, one should smoothen excitationtime histories (increase pulse width,reduce peaks), and change the repetitionrate if possible.Contemporary Design TrendsMost of the design trends or schemesenhance the strength of noise andvibration sources. For instance, someenergy efficient devices are just morenoisy; faster operations (higher speedsor power densities), compact devices,switchable modes (leading to transients),“easier” assemblies (rattle and squeaktype problems), etc. lead to noisyproducts.Recommendation forResearchThe long term research issues (from apersonal perspective) include a betterunderstanding of machine element noisesources (especially non-linear sourcessuch as gaps, dry friction and time/varying parameters). New or improvedmulti-disciplinary models are needed(contact mechanics, surface mechanics,machinery vibro-acoustics, computationalissues, flow-sound-structure coupling,etc.). Novel ways to control noise, shock,vibration problems (especially transients)must be found. These would include thedesign of systems with “intentional” nonlinearities,better system design concepts,and the employment of active (smart)materials.Steve Marshall – Challengesin the design of low-noiserefrigeration compressorsRefrigerant compressors serve as theengine for the refrigeration cycle.Applications for refrigerant compressorsvary from household appliances for foodpreservation, heat pumps and single-roomcooling to industrial refrigeration and airconditioning. The sizes for refrigerantcompressors range from fractionalkilowatts to several hundred kilowatts ofpower. Compressor designs fall into twomain categories: dynamic and positivedisplacement. An example of a dynamiccompressor design is the centrifugalcompressor common in large commercialair conditioning. The three types ofpositive displacement compressors are thereciprocating, the rotary, and the orbitalalong with their derivatives.Stage III of EC Directive 2000/14 limitsthe sound power to 97 dB re 1pW for‘any machine that compresses air, gases,or vapor to a pressure higher than theinlet pressure’ and operates up to 15 kWof power. For compressors operatingat power higher than 15 kW, the soundpower is limited to 95 dB + 2 log (power).Although the directive serves as a goodstarting point, the compressor applicationsaffected by the directive are far too broadthan for the directive to command muchinfluence. Therefore, compressor noiselevels will continue to be limited bymarket competition and industry selfregulation.The Air-Conditioning, Heating, andRefrigeration Institute (AHRI) is theU.S. trade association representingmanufacturers of air conditioning, heatingand commercial refrigeration equipment.AHRI standards and guidelines are usedthroughout the world. AHRI providesaccess to its standards and guidelines,as well as information about how thestandards are developed and advancedglobally. Through the use of industrystandards and certification programs,consumers can be assured manufacturers'performance claims are accurate and rateduniformly, enabling fair comparisons.The purpose of AHRI Standard 530-2005 is to establish for the rating ofsound, vibration, and pulsation forrefrigerant compressors: definitions;test requirements; rating requirements;minimum data requirements for publishedratings; and conformance conditions.As part of Standard 530-2005, soundtests shall be conducted in a free field inaccordance with ANSI Standard S12.35or in a reverberation room meeting therequirements of ANSI Standard S12.51[ISO 3741]. Sound power levels shall bedetermined in decibels with respect to 1pW for the one-third octave bands.Compressor manufacturers are alsomindful of test standards addressing soundlevels produced by the equipment thathost the compressors. For example, thepurpose of AHRI Standard 270-2008 is toestablish for outdoor unitary equipmentdefinitions, requirements for testing andrating sound, marking and nameplate dataand conformance conditions. The ratingsshall be comprised of octave band soundpower levels, overall A-weighted soundpower level, sound quality indicator (SQI)per ARI Standard 1140 (optional), andone-third octave band sound power levels(optional).The purpose of AHRI Standard 1140-2006is to establish sound quality evaluationprocedures for air-conditioning andrefrigeration equipment. The procedureis derived from the work of Wells andBlazier, “A Procedure for Computing theSubjective Reaction to Complex Noisefrom Sound Power Data,” ASHRAE 1963.One-third octave band power levels areweighted to adjust for psychoacousticsensitivity to frequency and discreettones; they are then converted to a singlenumber, Sound Quality Indicator (SQI).Compressor manufacturers face twomajor design challenges that affect soundlevels: environmental-friendly refrigerantsand energy efficiency. Next year,consumption of hydrochlorofluorocarbons(HCFCs) must drop another 40% of 1989consumption levels. Alternate refrigerantsmust meet strict new requirements interms of ozone depleting and global2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org87

warming potential. Compressors of mostalternate refrigerants must operate at higherpressures. The higher pressures causegreater dynamic forces and gas pulsation.Dynamic forces and gas pulsation are thesources of unwanted sound and vibrationin a refrigerant compressor. Advances inattenuation methodology must accompanyalternate refrigerants.In addition to increasing the dynamicforces, alternate refrigerants possessan inherently higher speed of sound,and thus longer wavelengths. Longerwavelengths make reactive muffler designmore challenging due to geometric sizerestraints. The alternate refrigerantsalso suffer from low oil miscibility. As aresult, the mechanical components of thecompressor are insufficiently wetted forlubricating bearing surfaces and addingvibration damping. Also, to prevent oilfrom exiting the oil-refrigerant mixtureand then pooling downstream of thecompressor in the refrigeration circuit,oil separators are often added to thecompressor. The oil separators generateconsiderable noise of their own.Energy efficiency poses the second designchallenge to compressor manufacturers. Inaddition to increasing energy efficiency,variable speed operation reduces overallsound exposure and annoying cycling.However, the variable-frequency drivingforces are certain to excite a structuralor acoustic resonance. Energy efficiencyalso calls for shorter, more direct gaspaths through the compressor. The shortflow paths prevent using gas cavitiesas acoustic mufflers or plenums. If thecompressor design incorporates valves,the valves must be stiffer and valve seatsmust be thinner to prevent inefficientback-flow. Stiffer valves contactingthinner valve seats create higher levels ofvalve slap noise. Finally, energy efficientoil-less compressor designs (pumping orsloshing oil draws power) eliminate thesound and vibration reducing propertiesof the oil.The pursuit of improved energy efficiencyalso affects the sound environmentadjacent to the compressor. For example,the fastest growing segment of the airconditioning – heat pump industry is themini-split systems. The compressor in amini-split system is positioned just outsideof the occupied space rather than at theend of a long system of air ducts such asin previous unitary applications. Energyefficiency is also achieved by lengtheningheat exchanger coils. The increasedcoil surface area provides greater soundradiation potential for gas pulsation fromthe compressor.In order for consistent sound reductionacross the operating range of a variablespeedcompressor, attenuation devicesmust be developed with broadbandresponse. A compressor intake mufflerwas designed that applies the absorptiveproperties of melamine foam forbroadband pulsation reduction. Themelamine foam was discovered touniquely survive the harsh environment ofa refrigerant compressor.Improved test and analysis methods areneeded by compressor sound engineersfor addressing the design challenges.Dynamic pressure transducers, similar tomicrophones, measure a scalar quantityrepresenting the sum of the travelingwaves. A method was recently attemptedfor separating the positive- and negativetravelingpressure waves in the refrigerantcircuit. Digital signal processorsacquire and calculate the transferfunction between two dynamic pressuretransducers. Phase calibration between thetransducers is required.Marco Beltman – Design oflow-noise fans and air-movingdevicesInformation technology products arehigh volume products, and componentswill typically be used in various systemconfigurations. The main designconsiderations for these systems areperformance, cost, size, power consumption,and acoustic noise. The relative importanceof these vectors varies per segment. Themain acoustic drivers are usage models,customer returns, eco labels and purchasespecifications and competition. Theinformation technology industry has anextensive set of standardized test codesin place for measurements, operation,verification and declaration of noiseemissions, including harmonized ECMA,ISO and ANSI standards. Advancedtechniques are used to develop quieter fansand the comprehension of inlet, installationand mounting effect is critical. Numericalsimulations for air flow are feasible, butacoustic prediction models as design toolsremain a challenge. Fan speed control hasfound widespread adoption, resulting insignificantly quieter systems. Even thoughacoustical benefits of active noise controlhave been demonstrated, the cost and sizeimpacts remain a barrier for widespreadadoption of this technology. Extensive soundquality studies indicate that the sound levelis the main parameter governing annoyance,but that tonal content is important and thatgeographical variations are significant.StandardizationThe information technology industry haslong history of developing standardizedtest codes. The basic metric is theemitted sound power level, based onthe fundamental ISO 374x standards,supplemented by operator/bystandersound pressure levels, based on ISO11201. Specific information technologytest codes, such as the 10th edition ofECMA-74, include specifications foroperating conditions and include twomethods to assess the presence of puretones. ECMA 109 outlines a methodfor declaring sound power level tocover lab to lab and system to systemvariations. The information technologyindustry strives for harmonization ofstandards worldwide. Therefore ECMA,ISO and ANSI equivalent standards areperiodically reviewed and updated toensure one standard worldwide that iscurrent and relevant.88 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

InfrastructureAn extensive infrastructure is in placefor acoustic technology development,including anechoic chambers for acousticsound power and sound pressure testsand low noise measurement systems toaccurately determine the emission forquiet components. Source identificationis also addressed through more advancedtechniques such as acoustic holography,scanning laser Doppler velocimetry andlaser particle image velocimetry. Finally,subjective perception is studied throughbinaural recording, analysis and playbackTechnology DevelopmentStatusIn order to address the source emissionfrom fans and air moving devices theISO 10302 fan plenum was developed toquantify the impact of backpressure onthe acoustic emission. Recent advanceshave extended this approach to includeinlet and mounting effects. For example,in notebooks the air moving devicesare typically located in a small gapbetween parallel plates, impacting theinflow and exhaust conditions. This hasa significant impact on the air flow, andthe acoustic characteristics. Optimizationof the design for operating conditionsrather than free flow shows that a 2-5dB benefit can be realized. Predictionand optimization of the air flow of fansis feasible with numerical models, butacoustic simulations remain challenging.Although progress has been made inpredicting parts of the noise spectrum oflow speed fans, a prediction of the overallspectrum and the application as a designtool remains elusive. Therefore, numericaltechniques are complemented withexperimental techniques such as particlelaser velocimetry, which allows capturingtransient flow fields and correlating flowphenomena to acoustic noise generation.Extensive sound quality studies areconducted to identify and quantify theparameters that govern the subjectiveperception for information technologyproduct sounds. An example studyquantified the annoyance level to soundsfrom personal computers in multiplegeographies. The results demonstrate thatthe sound level is the main parameter, butthat tonal content is important and thatgeographical variations are significant.It is therefore important that metricsand procedures for the identification ofpure tones are already included in theinformation technology test codes.In addition to the source emission itself,the installation in a system is veryimportant because of changes in sourcecharacter and coupling to enclosureacoustic modes. In addition, vibrationcoupling may result in increased noise,but this is typically a smaller effect. Fanspeed control has found widespreadadoption, and based on temperatures andloads may reduce the acoustic noise by asmuch as 15 dB. Also, the benefits of activenoise control has been demonstrated,in which reductions of 5 to 10 dB wereobtained, but cost and size aspects remaina barrier for widespread adoption of thistechnology.Serguei Timushev – CFDprograms for pumps and fans;acoustical optimizationThe presentation is on bounded rotatingbladed pumps (and ventilators) withsubsonic flow. To this type one can relateaxial, radial, and diagonal pumps andfans, water-jets, other types of homeequipment like the lawnmower, vacuumcleaner, miniature wind turbine (installedjust on the roof of the house, etc.) Toget the level for further discussionand evaluation of ideas, methods, andsoftware, the main goal of CFD-CAAapplication to the pump and ventilatornoise problem must first be established.Industry people—engineers, researchers,manufacturers—are using CFD-CAAmethods and software capable ofpredicting absolute levels of pressurepulsations and sound power in the nearfield of rotating bladed machines withaccuracy +/- (3..4)dB. The processingtime will be an important requirement aswell. They need days for a computationaltest, not weeks or months.The definition of the noise predictionproblem is common for all types of bladedrotating machines. It is tightly linked topressure pulsation spectra. One can see aset of tonal components of different natureand usually proportional to the rotorangular speed. Generally BPF componentsdominate in the spectrum. There arecombined components and known caseswhere combined component dominates inpressure pulsation spectrum.Small-scale turbulence and other weaklycorrelated unsteady phenomena connectedwith back-flow and vortex-sheddinggenerate a wide brand spectral component(pedestal). Cavitation is a well-knownsource, but one can say the cavitationphenomenon is a very special case as thepump in a normal operation mode mustwork without developed cavitation, andeven in the stage of cavitation inceptionthe noise frequency is out of humanaudibility range. Thus one can put it outof consideration, anyway it stays as a bigchallenge for CFD-CAA modeling. Itis well known that from the first criticalmode (when the head starts to drop)pressure pulsations including BPF tonalcomponents begin to increase due to theeffect of caverns presence in the flow path.The most important feature of rotatingbladed machines is the acoustical(or propagating) part of the pressurepulsations exhibits a resonance behaviorthat from one side depends on the circuitcharacteristics and from the other side, onthe acoustic resonances of the flow pathand phase characteristics of excitation(e.g. ratio of number of impeller blades tonumber of diffuser vanes).One can state that pressure pulsation fieldconsists of two zones. The first zone (zoneof pseudo-sound) is located near the rotor.The amplitude of pressure pulsations inthis zone links to the blade loading. The2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org89

nonuniformity of flow parameters rotatingwith the rotor generates tonal sound. Theamplitude of pressure pulsations in thepseudo-sound zone rapidly attenuateswith increasing distance from the rotor.Generally in 15-20% of the centrifugalimpeller radius the BPF amplitude dropsby an order of magnitude. In the flowpath one can discover very close locationswhere pressure pulsations amplitudediffers by an order of magnitude that givesbig gradients of flow parameters.Features mentioned above bring a rathercomplicated picture of pressure pulsationsin the flow path where near the rotorone can see a pseudo-sound behaviorwith higher pressure gradients andaccompanied acoustical domain wherepressure pulsations field appears as aresult of phase interaction, interferenceon the walls and with acousticimpedance of the circuit. Even for thesimple volute geometry one can get anacoustical behavior in the outlet part withamplification of a BPF harmonic due tothe acoustic resonance. In the axial typemachine one can see that within a distanceof rotor radius from blade edges, pressurepulsations exist in the form of higherorderradial-tangential modes. Thesemodes rapidly attenuate passing throughintermediary modes to the first tangentialmode, which transforms to a plane wave.Based on a brief review of last decadepublications one can state a rather bigdifference in methods to predict pressurepulsations and noise in pumps andventilators. Speaking more precisely, thereare mostly no attempts in recent studies(at least opened to the public) to predicthydraulic noise generation in pumps(excluding AVM approach). But it is notenough to model and optimize adequatelysound generation and propagation inpumps. Thus for pumps one can state a 1Dwave equation solution method publishedby Chen almost 50 years ago that can beused if appropriate boundary conditions inthe form of acoustic disturgances will besupplied. The source of inhomogeneouswave equation is the key issue oftheoretical background.There are many methods and programsused in fan noise modeling but most ofthese methods are based on Lighthill’sequation analogy with far fieldapproximation. Actually this equationinitially was proposed by Lighthillmore than 40 years ago for the caseof small-scale turbulence and there isno decomposition procedure. In a taskof practical optimization this probleminevitably poses a question regarding thesource evaluation.The decomposition problem (on tovortex-mode and acoustic-mode) can beresolved by using the LEE approach, butdecomposition must be completed forboundary conditions as well. It seemsthe SNGR method or its equivalent canbe a promising approach for a broadbandcomponent prediction but is used mostlyfor jet flow noise and lacks experiencein fans and pumps. Under a set ofassumptions the strick decomposition ismade in AVM that includes decompositionof boundary conditions using acousticcomplex impedance. This enables thedefinition of the source of noise and thecontrol optimization of the design.Conclusions• Decomposition methods are not yetwidely developed in pump pressurepulsation prediction except AVM (tonalnoise only).• In fan noise predictions mostlyLighthill’s analogy is used where thebest results are reached for tonal noiseprediction by application of Kirchoffand BEM integration methods forunsteady CFD data.• For broadband noise CAA results canbe considered qualitative althoughthere is validation showing that withincreasing mesh up to 8-16 millionnodes LES+Lighthill’s variationanalogy (BEM) improves theprediction accuracy.• Using LES increases computationaltime to a few weeks for each case thatis inappropriate for optimization tasksMichael Dittrich – Low-noisedesign of complex machinesusing specific softwareLow noise design of machinery, equipmentand vehicles implies the incorporationof noise control principles into new ormodified product design. As machineryacoustics covers a wide range of metrics,requirements, physical generation andtransmission mechanisms, noise controlmeasures and corresponding analysistechniques, there is a need to structure thisactivity in a systematic manner. This isparticularly the case for complex machineswhich include multiple sound sources,transmission paths and sound radiatiors.Examples are combustion engine poweredconstruction machines with air coolingand hydraulics, vehicle interior noise withrolling noise, powertrain noise and HVACnoise or power tools with transmissionnoise, aerodynamic noise and tool/workpiece noise.Questions to be addressed for the designergenerally include the following.• What resources, such as time, analysistools and expertise are available toanalyse the problem? This will oftendetermine the effort required.• What is the noise indicator and therequired noise reduction?• This tends to imply the extent ofdesign modifications.• What is the relevant frequency rangeand what are the time and spectralcharacteristics? This will determine thefocus of noise control effort, and oftendepends on the noise indicator.• Which noise control measures can beconsidered? After identifying candidatenoise control measures it will dependon the design stage as to which onesare allowable within other designconstraints such as cost, efficiency,safety and others.90 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

• What is the best combination ofmeasures? Often, a combination ofnoise control measures is required toachieve the required noise levels.Today, a wide range of tools are availablefor measurement and prediction ofmachinery noise including numericalmethods such as FEM, BEM and SEA.Noise measurement and diagnostics arecommonly used to characterize the noisesituation. Many literature sources canbe found on control of various types ofnoise sources. All these tools can helpfullfil the noise target. But a systematicapproach can help streamline this process.Recommended practice for low noisedesign of machinery is described inISO TR 11688 parts 1 and 2 [1]. In thenineties, the European project EQUIP[2] was undertaken to further develop amethodology and supporting tools for thisapproach. A map was made of the lownoise design process using the so-calledSADT technique [3]. Two key elementsemerged from this exercise: design rulesfor low noise design and noise pathmodelling. These have been implementedin a software package called EQUIP+ [4].Design rules are especially useful inthe early design stages when selectingdriveline type and working process, butalso when identifying ‘Acoustic mistakes’such as structure-borne path flanking ornatural frequency excitation. There aregeneral design rules and more componentspecific ones, for example:• General rule: up to a limit, improvingof alignment or balance in rotatingmachines will tend to reduce noisefrom structure-borne sources.• Component specific rules for fans:operating at best fan efficiency wilminimise the noise emission; largerdiameter fans at lower speeds will tendto be quieter.• For many power components, there isoften a quieter type, for example screwcompressors vs. piston compressors,belt drives vs. gear drives, electricmotors vs. combustion engines.However noise will seldom be the leadrequirement.Basic formulas for sound power, spectralshape or insertion loss as a functionof parameters such as speed, loaddependence, materials, mass and stiffnessand others can point in the right directionand indicate the order of magnitudeof particular modifications. Especiallyinsertion loss formulas for the varioustypes of acoustic device are of use, suchas enclosures, elastic mounts, dampingdevices, shunt mass or silencers.The approach for noise path modellingimplemented in EQUIP+ is componentbased,which means that only theacoustically relevant components areincluded in a model, together with noisegeneration mechanisms, a receiver andairborne, structure-borne or liquid-bornelinks between them. Such a model isfirstly created visually to represent thenoise situation for a given machine, andmay be based on previous knowledgeor on measurements. Noise controlmeasures can already be identified fromrules for each component type and thelinks present. They are generally of thefollowing type:• Eliminate unnecessary noise generationdue to unbalance, misalignment,friction, rattle, unintended turbulenceor vortices, or other sources;• change a design parameter (e.g.structural damping or fan diameter);• change an operational parameter (e.g.engine speed or loading);• omit, add or replace component (e.g.belt drive instead of gear transmission);• change a connection (link) or adisconnect a component (eliminationof flanking paths including acousticalleaks);• add an acoustic device (e.g. damper,enclosure, silencer, elastic mounts).The following step is to quantify the noisepath model so as to allow parametriccalculations on the above mentionednoise control measures. Finally, the bestcombination of noise control measureshas to be determined using such a model.The calculation model is typically in theone-third octave domain and includescontributions from the most importantsound paths and the effects of severaloperational and design parameters.For complex machines, measurementof the basic noise characteristics willoften be the first step to identify mainsources. Subsequently, a noise pathmodel can be developed which allowsto identify relevant design rules, and if acalculation model is built, most effectivecombinations of noise control measurescan be determined.A wide variety of tools for low noisedesign of complex machines areavailable today. A systematic approachusing low noise design rules and noisepath modelling provides a means ofsimplifying and speeding up the process.References1. ISO Technical Report 11688 parts 1and 2, Recommended Practice for thedesign of low noise machinery andequipment, 1993.2. EQUIP Project Final Report, TNODelft, 1996.3. D. Marca, C. McGowan, StructuredAnalysis and Design Technique,McGraw-Hill, 19874. EQUIP+ User Manual, TNO Delft,2009.Mark Bastasch – Design ofwind turbines and farmsNoise Generating MechanismsWind turbine noise is produced by twosources—aerodynamic and mechanical.The aerodynamic noise level is generallythe dominant noise and is proportionalto tip speed to the 5th power. However,tip vortex noise is not usually significant.Mechanical noise sources include thegearbox, generator, yaw drives, and2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org91

cooling fans. Many standard noise controlmeasures may be used to minimize thisnoise. Typical noise control solutions suchas enclosures or silencers can not be usedto control the aerodynamic noise. Thus,the aerodynamic noise typically remainsthe most dominant source.Relative Importance of Noiseand Drivers for Noise ControlNoise is recognized as an importantfactor in the development and deploymentof Wind Turbines. The IEC 61400-11standard allows for the comparison ofsound power levels between models. Themarket place is increasingly competitiveand every decibel increase in turbinesound power level results in greatersetbacks to noise sensitive applicationsleading to fewer turbines or reducedproject size for louder turbines.Wind Turbine Noise ResearchResearch on wind turbine noise has beencarried out by both public and privateorganizations with the emphasis onaerodynamic noise. These research groupsare international and include:• Sirocco: Silent Rotors by AcousticOptimization• European Commission• Energy Research Centre of theNetherlands (ECN)• National Aerospace Laboratory NLR,The Netherlands• University of Stuttgart, Germany• Gamesa Eolica• GE Wind Energy• Risø DTU - National Laboratoryfor Sustainable Energy, TechnicalUniversity of Denmark• DELTA (Denmark)• National Renewable EnergyLaboratory (USA)• University of Salford (UK), Halmstad& Gothenburg (Sweden)Wind Turbine Test Facilitiesand Acoustic Tools toCharacterize SoundThere are various test facilities locatedthroughout the world including theNational Renewable Energy Laboratory(USA), Netherlands, and Denmark.Acoustical tools utilized include acousticarrays, parabolic microphones, andIEC 61400-11 methods (narrow and1/3-octave analysis). Acoustic airfoilcomputational design tools used includeXfoil, AIRFOILOPT (Risø DTU), andSILANT. Acoustic wind tunnel testing isalso performed.Outdoor Sound EmissionsThe sound power level of turbines isdetermined by IEC 61400-11: WindTurbine Generator Systems Part 11:Acoustic noise measurement techniques.This method uses a microphone mountedon ground boards located at hub height+ ½ rotor diameter from the turbine.Concurrent sound and wind speedmeasurements are collected with andwithout the wind turbine operating overa specified range of wind speeds. Fromthese sound pressure level measurements,the sound power levels are calculated(one-third octave bands from 20 Hz to10 kHz to be incorporated in upcomingupdate of the standard). The standard willbe updated to reflect a reference windspeed height of hub height rather than10 meters because of the confusion andcomplications in understanding windshear and the 10 meter height reference.Sound QualityWhile subjective criteria are not partof the IEC 61400-11 methodology thestandard assesses tonality using a narrowband analysis and also provides onethirdoctave band results. Amplitudemodulation (swishing or whooshingsound) has been noted by some. A recentUK study (Morehouse 2007) foundmodulation was an issue at only four outof 130 wind farms studied, and remainsan issue at only one. A modulationquantification method was suggestedby Lee et al. at the International WindTurbine Noise Conference (2009) inAalborg, Denmark.Wind Farm Sound PlanningWhen considering the development of awind farm, the following tasks are oftencompleted:• Identification of all noise sensitiveareas (residences, schools, hospitals,etc.)• Identification of setback requirements(roads, property lines, residences,protected areas)• Development of constraint map, windresource map, and initial turbine layout• Obtain sound power level data forproposed turbines used to developacoustical model• Iterative refinement of turbinelayout based on acoustical and otherconstraints.Non-acoustic factors may be as importantas acoustic factors and communityacceptance likely requires ongoingcommunity involvement. Good publicrelations and outreach are imperativeto create a positive attitude towardthe project. Ensuring communityunderstanding of the benefits does asmuch to foster this attitude as doescoordination with the community to avoidconflicts.Wind Farm SoundManagementIf complaints are received, it is importantto acknowledge and respond in a timelymanner. These may indicate a malfunctionor maintenance need. Wind turbinecontrol strategies may also be developedto reduce acoustic emissions.Wind Farm SoundMeasurementsThe IEC 61400-11 ground board is notpractical for long term measurementsas it is susceptible to damage and thepressure-doubling effect of mounting92 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

the microphone on a solid surface isconfusing to the public. To reducethe effects of wind-induced noise, itis recommended to use oversize orsecondary windscreens and to collectand correlate with local (ground level)and turbine (hub height) wind speeds.Potential needs in this area include thedevelopment of “certified” equipmentor standardization of windscreens anddevelopment of wind-farm-specificmeasurement protocol.DiscussionCFDQuestion: What is the typical time toobtain non-steady computational fluiddynamics (CFD) data?Answer: It depends on the objective.If the objective is just airflow, it willbe a matter of days to a week. If we doacoustics, we can be running simulationsfor months.Question: What is the main sound tunnelnoise source for the lawn mower shown?Answer: The blade can be the dominantsource for some machines; and in othercases it can be the engine.Comment: In a following presentationthere will be a demonstration of asimilar type of modeling, called noiseprototyping, where you can hear the noise.Low-noise MechanicalComponentsQuestion: There was an interestingcomment made about designing nonlinearityinto the system from the outset.Please expand on that?Answer: One example is when there is abacklash between the gears. People try tocontrol that backlash, but it is importantto make sure that the parts are meshingtogether or the lubrication is there.Rather than fixing the problem there,we try to fix the problem elsewhere inthe system. And we must make sure thetwo sub-systems are physically coupled.Then somewhere in the system you tryto introduce a discontinuously non-linearsub-system. For manual transmissionsit can be done very easily by having adual, triple, or four-stage clutch damper.When a vehicle manufacturer needs this,it is sent it to a vendor to try different(multi-rate) springs. Another way to dothis is by inserting significant dry friction,and we have seen through our detailedtheory and experiments that non-linearfriction solves the problem and viscousdamping does not. Thus this is an areawhich is completely barren. We tend totreat non-linear elements as if they are“evil” in terms of theory and in terms ofexperiments. In fact we make sure in allexperiments that non-linear elements aresomehow linearized to take advantageof the principle of superposition. In reallife, designers use non-linear components(and nature is non-linear), so why can’twe take those concepts and use them toour advantage. We need to be careful thatwe use non-linear elements to resolve theproblem and not amplify motions andnoise.Question: It’s a great idea, but theanalysis of it is hugely difficult, isn’t it?Answer: The analysis is indeedcomplicated. Rather than doing thetruly non-linear analysis, I would do ananalysis of the linearized system as afirst cut from a design viewpoint. OnceI’ve chosen a reasonable design then I domore a detailed non-linear analysis. Anoptimization based purely on non-linearsystem analyses is virtually impossible.Start with a linear system, gain someinsight. and see exactly what needs tobe done. Try to optimize based on thelocalized non-linear sub-system, notnecessarily on a global basis. So thequestion comes up again: What is therole of dynamic non-linear interactionsbetween sub-systems? The simplestexample I give to my students is: If onenon-linear sub-system is “King Kong,”you need a “Godzilla” to kill him. But becareful; what if they join forces? Thenthere will be double the destruction! Wehave actually seen experiments where thishappens. You need to control (what I call)an intentional non-linear system.Question: If you address this nonlinearityproblem issue, will it beconnected to prediction accuracy?Answer: In many of the noise problemsthere are often two issues. One is:Are you attacking the mean or areyou attacking the standard deviation?Generally what happens is mean ±standard deviation is not a symmetricproblem. As an example, consider that themean is very high; sometimes standarddeviation is then very low. I can design alousy (noisy) machine very consistentlyall the time. On the other hand if themachine is relatively quiet from adesign viewpoint, standard deviation istremendous. So what we try to do withthis kind of problem is to examine it interms of both mean as well as standarddeviation. That’s the key. Non-linearsystem design is far trickier. Controlsystem people have already experiencedthis issue. They try to minimize the nonlineareffect in order to solve the problem.Sometimes that can be implemented. Iknow many examples. We have foundit to be useful, but what are the genericprinciples? I think this is where moreresearch is needed. It is seen in active orsmart materials; one of the advantages isthat they are inherently non-linear. Theyare amplitude-sensitive, their propertieschange with frequency. For example, atone frequency strong damping is wantedthen at another frequency you want evenmore damping. To be amplitude sensitive,the damper has to be a non-lineardamper. There’s no way in the worldyou’re going to get a linear damper. Anumber of people have suggested particledampers, sand dampers, and so on. Theyare inherently non-linear. Sand is oneof the best for damping. I’ve had people2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org93

from India and China call me, becausesand is a good damper, and offer to shipme some. These are rather complicatedissues. They are related to sources as wellas paths and require long-term work. Youcannot get answers overnight.Low-noise Machinery andEquipmentComment: The questions were addressedto the panelists before the finalizationof their presentation. Those questionswere more addressed to manufacturers ofmachines than to members of institutionsworking on the reduction of noise. Thenumber of participants coming fromindustry and specifically manufacturers ofmachines has been limited in this meetingbecause of the economic situation. Thefirst four questions were linked to thereason why manufacturers get involved innoise reduction. We know that the answerdepends on the type of machine.Question: Is there an increase in theimportance of low-noise criteria for amachine or is the importance diminishingnow?Answer: Let me give you one perspective.I’ve had discussions with companyexecutives, the people who dictate thevehicle designs, and they say that thesuggestions we have for noise controldo cost money. If there are minimumcostnoise control suggestions, they arewilling to listen. That’s true of manyindustries which question the solutionswe come up with. We have to minimizethe system complexities—especially theband-aid solutions that we attach duringproduction. We have to impress on themthat they could save money through properdesign. They should put more resourcesinto producing low-noise sources at thedesign stage. I don’t have an answer; thisis just a management perspective.Comment: There needs to be a changein values. If you offered a car companya solution to make the car safer, they’dthrow money at you.Comment: Nobody will throw moneyat you for anything. They are willing tolisten to you, but you have to prove it.It has to work, not only for one time inthe lab, but it has to work in production.I think that’s the key. Everything is on avolume basis—proving it for one vehicleor one component doesn’t cut it—it has tobe across the board.Comment: A common question raised bymanagement when you propose a noisecontrol solution is: How many dB perdollar? What’s going to be the incrementalcost of putting in grommets to isolatea component or doing something else?There’s going to be the question: What’sthe relative benefit? That’s difficult toanswer.Comment: As a contract researchorganization I can add that whenmanufacturers have a problem, a noiseproblem, they come to you and offer youmoney to consult.Comment: Often the question asked:What is the consumer willing to pay forthe product noise differentiation? Theconsultant is contacted when there’snegative impact on the bottom line becauseyour product is noisy. But if you arepositive—let’s say your product noise isthe same as the last generation, but thefunctionality, performance, or energyreduction improves and the productacoustics stays the same—it will notimpact the bottom line. So it’s not onlyabout noise, but how much the noiseimpacts profits and in what situation thenoise problem becomes a factor. Again,the question comes down to how muchmanufacturers are profiting from theconsumer who is willing to pay for loweror better product noise. If you consider theautomobile or home appliance industry,there are product models where acoustic/quiet is one of the key attributes that definea higher-class product. In those situations,consumers are willing to pay for acousticsto some degree. But for many otherconsumer products, acoustic/quiet is notone of the key product attributes. In thosecases, acoustics/quiet becomes importantonly when there are negative rather thanpositive results (return issues, perception ofpoor quality, etc.).Low-noise ProductRequirementsQuestion: Where does the requirementfor a low-noise product come from(regulations, management, purchasers,end-users, or other manufacturersintegrating the product)?Answer: First of all there is the usage.For example, the device in a home-typesetting, in a living room, has to be quietenough to be accepted by end users.Others are the competition betweenmanufacturers and product returns/servicecalls. Another driver, especially in Europe,are voluntary eco-labels and purchasespecifications. Those are important driversin the IT industry in terms of acoustics.Answer: Refrigerant compressormanufacturers sell to technicallyknowledgeablecustomers who integratethe compressors into the product systems.So for compressor manufacturers, theincentive to produce quiet compressors isalmost entirely driven by the integratingmanufacturers. There’s an interestingbalance that the integrating manufacturerperforms. He typically has some noisecontrolexpertise on staff. He would liketo have a quiet compressor, but he doesn’twant to pay for it. He makes a judgmentas to whether it’s better to pressure thecompressor manufacturer to quiet thenoise or just quiet it himself. They havemethods such as enclosures, blankets, andother methods that get the noise down toacceptable levels.Answer: There is yet another motivatorfor some products which is the warrantycost. Do you have a product with awarranty? Either noise or some othermalfunction can be the problem. If youtake it back to the dealer, there may be asubstantial cost. Unusual noise problems94 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

could come under the warranty umbrella.That may be very costly in some cases.Comment: In many consumer productsnowadays, the margin or net profit froma product is very small; so if the noiseindicates to the consumer there is somemalfunction or a low-quality product waspurchased, the consumer may return it.They’re earning, say 1 USD of marginon the whole product, but their warrantyreturn cost is 100 USD. So product-relatednoise issues that may trigger consumerreturns are a big headache because ofcost; and that’s where a lot of attentionand research is devoted. But it’s afterthe fact. Often you want to discover theproblem much earlier to avoid the cost.You are constrained by integrated parts.Let’s say if it’s the noise from a littlemotor in a printer, you want to constrainit much earlier preventing any productreturn occurring because of the warrantyon the product.Comment: This is the kind of issuewhich never gets written up in any of thetechnical papers. Sometimes companiesactually do analysis as a motivating factorfor low-noise products.Product Integration andProduct ReturnsComment: At Hewlett Packard weintegrate components into a system. Webuy hard drives, for example; and we haverequirements for our vendors. If there isan issue with hard drive noise or a failure,then the hard drive or faulty componentgoes back to the vendor to determine theroot cause of the problem. Where is thefailure? But the warranty cost, as waspointed out, is very high even if there’snothing wrong with the hard drive orcomponent. Sometimes people will log infield returned systems, bring them downto the lab and ask if they meet the spec ornot. But, it really doesn’t matter because,if the customer is not happy, the damagehas already been done.Comment: I’m not sure about thepaper aspect of this. There is enoughinformation internal to a company orshared between the supplier and themanufacturer. They’re usually defined byspecs. The specs are very detailed.Comment: Another problem thatsometimes comes up is that a productis returned because the customer is nothappy, but the people fielding the returndon’t get very good information fromthe customer. They may say it is a noiseproblem, but they don’t say whether theyare bothered by a high-frequency soundor what. Is it a whining noise or is itintermittent? They don’t get very goodinformation, so it’s important to try tounderstand what they were complainingabout. There are many aspects to the enduser interface with a product— noise isone of the factors.Quiet Product CostComment: When you discuss theseproblems with top managers, you saidyou must not add weight, you must notadd costs. Does this mean that you don’tget the job to fix the problem? To quote adistinguished colleague: “There is no lawof nature that says that a quiet product ismore expensive than a loud one.” Haveyou good examples?Answer: The first example is wheneverI talk to management, because we are inthe academic business, I attempt to getmoney for research, not to fix problems.I’ve learned never to promise an answerbecause innovative answers sometimes arenot attractive answers. We had a workshopwhen we started our NSF Smart VehicleConcepts Center, and we discussed anumber of different actuators. Somebodyfrom industry got up and said that theyhad a roomful of these actuators—veryinnovative—but most of them are noisy.They’re never going to make it to themarket. So you can have a number ofinnovative products, but some of themwill never make it because of noise orother considerations. Whenever I talkto management, I tell them that this is along-term process. You need to aim fordesign, not necessarily band-aids. A bandaidwill always cost you more money eventhough it seems like only 2 USD here, 0.5USD there, it becomes significant money.So a research project is cheaper comparedto the band-aids if it leads to a solution.Not all projects will lead to a solution.Sometimes our answer is to do moreresearch.Comment: Regarding the noise ofrotating machinery, a simple, low-noisesolution may be contradictory to thepower requirements and the efficiencyof the machine. Solutions for lownoisedesign may be needed whenmanufacturers increase, for example, thepower and efficiency of the machine suchas the cooling capacity of fans. In thatcase inevitably it increases the noise; butif we try to reduce the noise, the efficiencyor the power may be degraded. It may becostly to find a good solution.Question: How are relations managedbetween the manufacturers of noisegeneratingcomponents and themanufacturers of the complex machinesintegrating them?Answer: This question is highly political,and the answer depends on cost. Leads tofinger pointing—it’s your fault; you payfor it. This is a most difficult question.Noise ResearchQuestion: The next question is linked tothe way a company—small or mediumsized—copes with noise research. Myown experience is that, with the exceptionof the automotive industry and other largecompanies like Caterpillar, there is onlya limited ability within the company towork on noise issues. This explains why,depending on the situation, the problemmay be handled either inside the companyor outside. The question is related to thecost of the test facility and equipment.How many people are involved in acompany to cope with noise issues?2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org95

Answer: I have learned while supportingproduct development in the U.S. that,as far as HVAC is concerned, productmanagers are very optimistic. Theybelieve from the point of conceptthrough paper design that their productis inherently quiet, without any need forconsideration of sound and vibrationprevention. It’s very difficult to convincethem that they need to do certain thingsbefore they actually build a product,because this goes against their optimisticviewpoint. When the hardware arrives andthe sound and/or vibration levels exceedexpectation, they believe something iswrong with the hardware, and they askthat the “problem” be fixed. If you reachinto your sound and vibration toolboxand apply a cure (a damping treatmentfor example), you have effectively shotyourself in the foot. The product managerwill continue to believe that the designwas good, but the hardware was notbuilt as intended. Sound and vibrationprevention early in the design cycle is stillnot considered. I had a profound momentwith a roomful of executive managersshortly after everyone listened to a ratherloud compressor. I had been frustrated;they were frustrated when I finally posedthe problem in a different way. I toldthem that this compressor is not too loud.It’s making exactly the sound that it wasdesigned to make. If you want it to makelower sound, you need it to design it to belower. That’s the kind of thing that I thinkneeds to be done more often.Comment: This is a good exampleof a medium-sized company whichmanufactures a product which is a criticalcomponent when it is integrated in largerproducts. Even then there is only oneperson to cope with the problem. That’svery common.Comment: The key word here is thatmanagers think in terms of noise—somehow fix it. In other attributes theywill ask you to study it and analyze it.Somehow you can find a magic fix, findsomething to make the problem goesaway. Where there’s an energy issue,we’ll study and find alternate solutions.Whereas noise is kind of an afterthought,now we have it, though we didn’t expectit, but it happens almost 100 percent of thetime. It would be a pessimistic outcomeeven though they are optimistic designs.Comment: In these situations the productmanagers believe the acoustician has asort of magic wand. This is not possible inmany cases.Comment: Intel has a research groupcalled Intel Labs that is the centralresearch facility at Intel. We have ahandful of acoustical engineers—two inOregon and two in Guadalajara, Mexico.We study the source, the transmissionpaths, and the receiver aspects in ourresearch groups. Then we work withour business groups, and they then workwith OEMs and HV or vendors on thetechnologies.Comment: IT technology is much furtheradvanced than most other industriesbecause of the past and current interestin the field. The problem of noise in thistype of machine demands specializedeffort. This is not generally the case. Forexample, we are in a room where thereis supposedly a silent HVAC system, butthis is not really the case. Nonetheless, itis a much better place compared to placeswhere people work in industry.Test Facilities and ToolsQuestion: How much is a company ableto devote to test facilities?Answer: Our research facility in Mexicois pretty well equipped. We also haveenvironmental labs that do the standardstesting for other business groups. They notonly test acoustics, but also do other typesof environmental testing.Comment: The long-term prospects fortest facilities in some companies do notlook good. The last couple of decades ofsevere cost cutting and “lean” operationhave seen little investment in testfacility construction and test capabilitydevelopment. These companies end updoing the most with what they have interms of test facilities. Often the engineerleans on experience acquired over years oflaboratory or field testing to compensatefor inadequate test environments.Investment is also lacking in the trainingof younger engineers in sound andvibration testing techniques.Comment: In terms of tools andsoftware, I’ve had some bad experiences.Management may sometimes beapproached by vendors with “magic”software to reduce the noise of theirproducts. The vendor claims this new toolwill solve for the company that which theclassical engineer has not been able tosolve. I have had experiences where themanagement of small companies has beenpersuaded to buy sophisticated software orequipment to solve a noise problem. Whatfinally happened? After six months or oneyear, the noise problem was not solved; sothey came back to us to solve the problemleaving us only two months in which to doso. A lot of money was wasted some yearsago in this way by companies in France.SESSION 2: LownoiseProductsPanelists• Goran Pavic, INSA Lyon, France(presented by Jean Tourret)Noise synthesis using a hybridsubstructuring approach• Chuck Hayden, NIOSH, U.S.A.Noise control by design of aircompressors and pneumatic hand tools• Bob Anderson, Consultant, U.S.A.Noise reduction at source inmanufacturing plants and workshops• Bill Lang, Noise Control Foundation,U.S.A.Low-noise household appliances96 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

• Tom Reinhart, Southwest ResearchInstitute, U.S.A.Low-noise, off-road recreationalvehicles• Egons Dunens, Hewlett Packard,U.S.ANoise reduction at the source in officesPresentationsGoran Pavic – Noise synthesisusing a hybrid substructuringapproachPosition in IndustryA low-noise product is difficult toconceive at the design stage because ofthe following:• permanent improvement of industrialproducts needed• quick prediction of noise at the designoffice level required• component suppliers and productassemblers lack coordination• profound shortage of information onnoise of components• noise regulations exist for finalizedproducts, not for components• no design data on the link betweenvibration, pulsation and noise• software for noise prediction difficultto use, requires extra skill• software lacks reliable handling ofnoise sources.Typical Industrial ProductA product such as a washing machinehas three “acoustical” elements: sources,connections, and frame—in the same wayas a violinClassical Protoyping for NoiseThis is a multifaceted work where testsare done on an assembled prototypeand where different noise sources arecompared to each other. To reducenoise there may be modifications tothe connections and mainframe toincrease stiffness, an adjustment of thecomponent’s position within the frame,or the use of absorptive material anddamping layers.The classical output is the noise spectrumat a reference position and/or the totalpower radiated, but it can also be asubjective noise assessment by made bylistening. Virtual prototyping should carryout the same phases but on a computer.But vital information and data must betaken from the real world!Sub-StructuringThis is the backbone of virtual acousticprototyping where the principle is tobreak the unit down into its componentsand analyze each component separately.Then the coupling forces at interfacesmust be identified and the global behaviorreconstructed.Virtual Noise Prototyping Using NoiseSynthesis Technology (NST)The objective of NST is to predict theimpact of alternative solutions andmodifications of an industrial producton its global noise using an industriallyfeasibletechnology. This may be appliedto any industrial object which can bedecomposed into an assembly of noisesources and noise transfer paths (airborne,structure-borne, fluid-borne). NSTshifts from the scale of fine detail to thescale of entire mechanical components.At the component level, computing isusually replaced by measurement evolvinggradually toward either empirical, scalinglaw,or simplified analytical models. Theinitial development of NST technologywas done within the EC project GRD1-10785 Noise Abatement using ConcurrentComponent Optimisation.Summary of NST ApproachThe NST approach is to make things assimple as possible, but not too simple.• The source is characterized ina deterministic way by directmeasurements (Component SourceStrength CSS)• The connections are characterizedby either measurement (e.g. rubbermounts) or computation (e.g.couplings) (Connection TransferFunction CTF)• The frame is characterised in astatistically averaged sense in orderto account for its sensibility toperturbations (Frame ConductivityFunction FCF)Comprehensive SourceCharacterizationAll effective noise-generation mechanismshave to be considered. The three typicalmechanisms are air-borne (radiation fromhousing), structure-borne (feet, pipes,connectors), and fluid-borne (gas/fluidpulsations).Source Characteristics (CSS)NST requires adapted methods anddedicated test rigs. Standardized testmethods are generally unsuitable foran NST approach! Examples are thecharacterization of structure-borne noiseof an electrical motor using the Blocked-Force method and the characterisation ofair, structure-and fluid-borne noise of asmall hermetical piston compressor usingthe 6-accelerometer and 3-pressure sensormethods respectively.Characterization ofConnections (CTF)Either measurement or computationis possible, but the characterisation ofcertain types of coupling elements, likerubber mounts, will have to be doneexperimentally. In opposition, metalliccouplings of well-defined shape andmaterial properties are most convenientlycharacterized by computation, e.g. usingFEM.Obtaining Frame ConductivityFunction (FCF)The characterisation of frame is atechnology uncertainty problem.Nominally identical structures can give2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org97

different acoustical signatures. Smallvariations in the machining, assembling,and installation will smear the frequencyproperties of different (flexible) frames.Frequency smoothing techniques are usedto get transfer functions of transmissionpaths.Noise Synthesizer (NS)NS is the tool for virtual prototyping.Noise prediction is done with the help ofmulti-task software to which is suppliedinput data obtained on both the sourcesand the frame! It uses a particular noisesynthesis scheme defined by the user. Thefunctions of NS are:• select the least noisy component(s)relative to the given frame• rank different noise transmission paths• predict product noise• get an appreciation of product noisequality• assist in the analysis of noise reductionThe basic output of NS is to produce anoise spectrum of the assembled productand to synthesize product noise for audioreproduction.Noise SynthesisNS is a chain of complementaryoperations. Synthesis of a noise waveformmay be done from a RMS noise spectrumin case of random or periodic signalsor by convolution of impulse responseobtained from FRF Transform.Example of a Walk-BehindLawnmowerNoise-generation mechanisms can be splitinto engine noise (radiated directly byexhaust, and by its structure, or indirectlyby vibrations induced in the deck) andblade noise (radiated in the deck outlet,through the leakages between deck andgrass, and inducing vibrations in thedeck).Example: Noise SynthesisThe approach for a ride-on lawnmowerincludes:• blade characterized as a noise sourceon a specialised test bench• deck characterized by its insertion loss(loudspeaker excitation)• engine characterized by partial soundpowers emitted (6 faces)• engine structure borne characterized byengine/chassis mobilities• exhaust characterized by near fieldmeasurement using reciprocity• free-field propagation away from themower assumed.SummaryThe main features of NST technology byhybrid sub-structuring are that it:• is suitable for a large variety of products• offers increased independence todesigners• enables noise data exchange betweensuppliers and assembler• is product-dependent• provides improved understanding ofnoise generation and transmission• enables noise prediction & listening• allows assessment of noise reductionby designThe main benefit of NST technology isvirtual prototyping.Chuck Hayden – Noise controlby design of air compressorsand pneumatic hand toolsThe focus for controlling noise emissionsfrom air compressors relies heavily onbarriers and enclosures for blocking noisepathways. Control of noise emissions forpneumatic hand tools is more generallyfocused on muffling or redirecting exhaustair from the device itself. While both typesof products are known to emit high levelsof noise, manufacturers of air compressorscan more easily recommend the use ofadministrative controls such as locatingthe compressor in areas isolated frompersonnel. Conversely, manufacturers ofpneumatic hand tools can be certain theirproduct will be used in close proximityto the tool operator or other personnel.Regulatory emphasis on noise emissionsfrom both products is typically drivenby environmental considerations and notnecessarily to reduce noise levels likely tocontribute to an operator’s noise inducedhearing loss.Manufacturers balance the target market(high-, medium-, or low-end), energyefficiency, and reliability into theirproduct design. Over the last few years theincreasing importance of environmentaldesign, with noise emissions beingof particular concern, is a strongconsideration. Additionally, pneumatichand tool manufacturers must considerergonomic issues such as vibrationisolation and hand grip design into theirproduct. Some design constraints relatedto noise control of hand tool designsincorporate the muffler into the hand gripwhile ensuring the grip is not so widein circumference that gripping becomesdifficult or uncomfortable. A mufflermay reduce noise emissions but at theexpense of a significant reduction in thepower of the tool. The additional weightof the mufflers must also be considered aspart of the overall ergonomic evaluation.Added costs associated with noise controldesigns are difficult to quantify, but usingcompressors enclosed in canopies as areference, the extra cost is typically 5percent. The cost for noise controls onhand tools may be significantly higher asthe complexity is increased and the overallproduct cost is lower.In 1969 the manufacturers’ tradeassociations in the US and Europedeveloped the CAGI-PNEUROP TestCode for the Measurement of Sound fromPneumatic Equipment (ANSI S5.1 1971)to enable air tools to be measured andcompared. More recently manufacturersselling to the European Economic Areahave been obligated to comply with theMachinery Directive (MD) requiringmachinery to be designed so the risks fromnoise emissions are reduced to the lowestlevel while taking into account technical98 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

feasibility. Also the noise emission valuesmust be stated in the manual accompanyingeach machine. More recently, Directive2003/10/EC has imposed a responsibilityon employers in the EU to manageand control the noise exposure of theiremployees. This has resulted in powertool purchasing policies specifyingrequirements for noise emissions. Forcompressors, products for outdoor use areregulated by specific legislation: OutdoorNoise Directive 2006/14/EC (Europe)and the Noise Control Act 1974 (USA).The products for industrial use indoorsare governed by the regulation of noiseexposures in the work place. However,noise exposures in industries such asconstruction, a large component of thepneumatic hand tool market, find littleenforcement in the U.S. Never the less,environmental regulations continue tobe strengthened regarding general noiselevels. This is particularly to be found inmunicipal regulation and enforcement suchas the recent New York City Departmentof Environmental Protection (NYC DEP)noise regulation. Within the NYC DEPregulation is a focus on constructionsites within the city and a vendor list ofrecommended quiet equipment. Becauseof this, manufacturer’s have a strongeconomic motivator to produce andmarket quiet equipment within the NYCconstruction market. This trend can beexpected to expand across the countryas communities become more proactiveagainst the adverse effects of high noiselevels in their cities and neighborhoods.Industry influence on the development ofnoise level test standards for pneumatichand tools has resulted in the inclusionof statements such as “… declaredvalues are not adequate for use in riskassessments…” in existing test standards.This includes those of ANSI, ISO, andEN. The statement which diminishesthe need for gathering such data isprimarily for use in assessing whethera hazardous environment exists or forinformational purposes in choosing andusing appropriate personnel protectionequipment. Revision or development ofproduct noise level emission standardsshould first consider why the standardis needed in the first place—Is thetest standard drafted for productdevelopment, operational diagnostics, orrisk assessment? The need for relevantstandards to assess the hearing hazardto operators of machinery and tools issignificant and should be addressed. Ifnot, hearing loss among certain groups ofusers such as construction workers willcontinue to be high.The hand tool industry tends to designtheir noise control components, mainlymufflers, in-house. In the compressorindustry, most co-engineering occursonly between suppliers of noise-controlcomponents for the integrated package.That is components not specificallydesigned for noise control are not coengineeredfor quiet with respectivemanufacturers. The industry states thatall product design personnel are involvedin noise control as an integral part ofproduct development. Noise controldesign is such that without designengineers specifically trained in acousticsand noise control, the opportunity for asignificant noise reduction is diminished.Industry should do more to seek technicalexpertise with formal training andexperience in engineering noise controland acoustics. Sound level testing forhand tools is accomplished in accordancewith ISO 3744 and test rigs, as required,in accordance with ISO 15744. Forcompressors, a number of environmentsare used depending on whether thecompressor is portable (open-air, noisescanningyard) or stationary (test cellssuitable for near field noise scans)with special test rigs used occasionally(analysis silencers, evaluation rotordynamics,rig/equipment allowing formodal analysis).For air compressors and pneumatic handtools, sound quality is typically not aconsideration. As the products’ noiseemissions are reduced over time, this areaof research could become more important,particularly with hand tools and the tooloperator’s desire for auditory feedbackduring the tool’s use.RecommendationsThe revision of existing noise level teststandards is necessary to be applicablein noise hazard risk assessment. Futurestandards should be web-based, writtenconcisely, and include HTML links tospecific issues now described in full inwritten standards. Future standards draftsand revisions should include spreadsheettools to streamline what is now a heavydependence on complex written equations.Existing noise level test standards areinadequate in providing a noise levelmeasurement relevant to the operation of themachinery or equipment; this is particularlytrue when the product is hand-held.Bob Anderson – Noisereduction at source inmanufacturing plants andworkshops(Prepared by Noise Control Foundationfrom Bob’s presentation)Fundamental QuestionsThe following fundamental questions areasked about noise control in industry:• What is the state of noise controltechnology for industrial equipment?• Does the cost of noise control impedeimplementation of quiet technology?• What drives the decision to implementcontrol technology?• What resources are available to thosewho responsible for integrating noisecontrol technology into equipment?• How is the control technologyevaluated? Are there benchmarks anddesign goals for sound emission levels?What Drives Noise Control?In established heavy manufacturing, largecompanies are influenced by unions,compliance, and the need to control costs,including medical; Buy-Quiet programs2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org99

are drivers. In small companies controlof cost and compliance are recognizedbut there are few Buy-Quiet programs.In “green” technology manufacturingfor both large and small companies,compliance and medical costs areinfluencing factors; and Buy-Quiet andretrofit programs are drivers.Motivating Factors in Buy-Quiet ApplicationThere are several motivating factors inBuy-Quiet applications.• New equipment whose operation willnot appreciably increase noise levels inexisting work environment.• Minimize cost of engineering noisecontrols.• Combine with other standards andcontrols to achieve added benefitfor metal-working fluid control andergonomics.• Introduce added efficiencies through“re-engineering” and improvement ofprocesses.Adantages to Adopting NoiseControl in New EquipmentThe cost for noise control in the design/build stage is less than in retrofit, andcontrols can be integrated into the design.Controls have less potential penaltiesto production and maintenance, andthe costs of controls are covered underproject costs and new capital equipment.Another advantage is the use of supplierknowledge supplements limited inhouseprocess noise control engineeringexpertise.Impact of New Technologiesand Supplier RelationshipsNew technologies make possible processautomation which includes roboticfunctions to remove or replace worker,multi-function equipment where theoperator becomes the monitor, andpositive part control. Collaborativepurchaser-supplier relationships makethem partners-in-design using thesupplier’s process design expertise andencourages design initiatives and alternateprocesses.Manufacturing processes includemachining operations and heavymanufacturing power presses (sourcecomponents and controls), and assemblywelding. Support processes usecompressed air systems, hydraulic powerunits, and hand tools.For forming operations enclosures aredesigned to control metal-workingfluids, oil mist, smoke, and noise andresult in sound emission levels below 90dB(A). The enclosure also serves as amachine guard. For machining operationsenclosures serve multiple functionsincluding guarding and result in soundemission levels, under load, below 80dB(A).For transfer presses, enclosure of dieareas, drive-train, and de-stackingareas results in sound levels under fullproduction below 85 dB(A).For metal assembly weld cells replacingpneumatic drives with servo drivesreduces noise from spot-weld impactswhile extending weld-tip life and savingenergy. Worker noise exposures are lessthan 85 dB(A).Commercial controls for compressedair noise are available for air jets andpneumatic exhausts, and hydraulic surgesuppressors provide noise control forhydraulic power systems.Noise control is achieved for power toolsby replacing pneumatic tools with electrictools and impact wrenches with impulsetools.Die design activity is typically contractedto competitive design firms who may notconsider noise control techniques.In part and scrap ejection systemsthe machine supplier is typically notresponsible for noise generated by tooling,loading, and material handling. For thesesystems controls are assumed by thebuyer who may not have noise controlexpertise. In many production equipmentinstallations, the buyer is also responsiblefor machine mounting and vibrationisolation is often not considered as anintegral component of the installation.There are technical issues and supplierissues which present limitations andobstacles to successful noise reduction.The technical issues are manual loadand unload, tooling, and materialhandling. The supplier issues are lack oftechnical expertise, lack of direction and/or expectations, and misapplication ofmaterials. An example of misapplicationof materials is the use of unprotected,open-cell urethane foam in newequipment.An example of misapplication of processmay occur due to the inappropriatelocation and selection of the paint spraybooth. If a vane axial fan is located closeto the operator’s position, it will negatethe positive effect of the spray boothenclosure itself.Convenience materials include thosethat are readily available in a shippingoperation, for example, quilted blankets.These materials are increasingly used forretro-fit enclosures and are unsuitablebecause the sound transmission loss theyprovide is inadequate, and any moneysaved by their use should be spent onmaterials with a high transmission loss.Measuring Noise ControlsB11.TR5-2006 - ANSI Technical Reportfor Machines: Sound Level MeasurementGuidelines specifies methods formeasuring, evaluating, and documentingsound pressure levels emitted by amachine production system during normaloperation and when running at idle. It isintended to be most compatible with theactual conditions encountered in industryand permits the selection of equipment100 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

using ‘buy-quiet purchase specifications’or to estimate the effect machinery willhave after installation. The location of themicrophone is on a measurement envelopethat encloses the machine at a distance ofone meter from the closest surface of themachine.Conclusions• Commercial and process noise controlsare available for application in mostnew equipment installations.• Cost is a major factor in decisionsto implement control technology,especially in retro-fit applications.• Within the US, the hearingconservation compliance alternative toengineering controls discourages retrofitactivity.• Within the manufacturing userbase there is a lack of noise controlawareness and expertise. There islimited knowledge and expertise withinthe supplier base.What is needed?• A standardized noise emission labelingsystem needs to be developed.• Strengthen existing measurementcriteria by adding provisions forimpulsive noise emissions, promotingaddressing “machine system,” andadding consideration of vibration andshock isolation.• Enhance supplier and user awarenessand expertise through technicaltraining in measurement and controlfundamentals.• Make the case for added value of lownoiseproduct.Bill Lang – Low-noisehousehold appliancesThe Association of Home ApplianceManufacturers (AHAM) classifieshousehold appliances in three categories: 1)major home appliances, 2) portable homeappliances, and 3) personal care appliances.In the first category garbage disposalunits, dishwashers, room air-conditioners,and clothes washers and dryers areprincipal sources of noise complaints.In the second category fans, vacuumcleaners, food processors and mixers aremost often criticized for their noise. Inthe third category only hair dryers are ofconcern as being noisy.Requirement for a Low-NoiseHome ApplianceAs hearing is not threatened, therequirement for a low-noise homeappliance is principally market-driven bypurchasers and end users. In Europe thereare eco-labels with noise as a criterion.Low Noise PerformanceVersus Other CriteriaSales price and performance are thedominant criteria for home appliances.Secondary criteria are robustness, energyefficiency, design attractiveness, and lownoisewhich are all important. The moreintrusive its sound, the more important itis to have a low-noise product.Noise Research andDevelopmentFor a typical home-appliancemanufacturer, the number of peoplewho are involved in noise research anddevelopment is small. Often engineersare “jacks-of-all-trades” working one dayon one of a variety of mechanical aspects(e.g. heat transfer) and the next day onproduct noise.Extra Manufacturing Cost forLow-Noise ProductsThe extra cost is easier to estimate forsome products (e.g. dishwashers) thanfor others. Overlapping of model changesmay present difficulties in estimating thisextra cost; for example to transfer a recentdevelopment into a new model (e.g. aquieter way to support a drive motor).Mechanical Power SourceThe noise emitted by the mechanicalpower source of a typical home applianceis usually a significant contributor to theoverall noise emission of the product.Measurements of CompetitionIn the home appliance industrymeasurements of competitive products,including noise emissions, are routinelyperformed.Information for the PurchaserThe purchaser of a home appliance needsthe means to compare the noise fromone product to another and the ability tocompare the noise of a product to onewith which the purchaser is familiar.Currently the metrics used to describe thenoise emissions of home appliances aredefined by the IEC.Subjective Sound QualityMetrics related to subjective sound qualityare used for some home appliances. Theseinclude listening panels (such as those usedby Consumers Union) that may entail ajury trial rather than a specific metric.Test FacilitiesBecause of their size, most householdappliances are suitable for measurementin portable and small chambers that areinexpensive compared to those requiredfor larger sources. The test code used bythe manufacturer determines the optimumdesign for these facilities.Example: DishwashersCompetitive Claims• “Bosch dishwashers are the quietest inthe U.S.” (manufacturer’s claim)• “World’s quietest dishwasher,Kitchenaid Superba EQ, at 41 dBA perIEC Standards.” (manufacturer’s claim)Role of Dishwashers• Unit frequently installed in openkitchen near a dining or family room.• Cycle times may exceed one hour.• Of all home appliances, dishwashershave potential for significant intrusionon family life.2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org101

Today’s TechnologyTop-of-the-line dishwashers are quieterbecause of:• Smaller, vibration-isolated, variablespeedmotor (3/4 hp reduced to 1/8 hp)• Two small pumps individually washand drain• Solid-molded, single-piece base blockssound• Longer cycle time (35 minuteslengthened to 1 hour 20 minutes)• Hard-food grinder replaced by cleanoutfilter• Hot-air blower for drying replaced byheater element or very hot water• Heavy-weight sound-absorbing blanketcovers tub• Sound-dampening mastic on exterior oftub reduces noise from interior of tub• Alternating wash zones reduce watersounds by reducing amount of waterused at any timeResults: “The New Soundof Silence” (manufacturer’sclaim)• Engineering improvements produce“world’s quietest dishwasher” at 41dB(A) per IEC standards.• Bottom-of-the-line dishwasherswithout engineering improvementshave noise ratings up to 65 dBA.• 20-25 dBA engineering improvementsoffer nearly silent operation.• Comparison with early dishwashersdemonstrates considerable progress innoise control technology.Technology Assessment• Sales of household appliances areprimarily market-driven.• Availability on current market of manylow-noise appliances demonstrates thattechnology is currently available.• Market for low-noise appliancesdepends partially on location ofappliance within the home as well ascycle or operating time.• Demand for low-noise appliancesdiffers by geographical region.• More uniformity of test codes acrossindustry would facilitate noisecomparisons of competitive products.• Low-noise household appliancesgenerally sell at premium prices.• Often the ‘greener’ the product, thequieter the product.Tom Reinhart – Low-noise, offroadrecreational vehiclesIntroductionThe types of vehicles considered in thispresentation include:• Snowmobiles• Jet skis• Off-road motorcycles (dirt bikes)• All-Terrain Vehicles (ATVs)• Micro- and Ultra-light aircraftEach type of vehicle presents a rangeof issues and technical challenges.Regulators will want a easy to performnoise test that has high repeatabilityand which represents the noise in actualuse. Efforts to reduce noise may causereductions in performance, as well asincreases in weight and cost. One majorfactor that comes into consideration foroff-road recreational vehicles is ownermodifications that intentionally increasenoise. This means that enforcement hasto be aimed at individual users, not just atthe vehicle manufacturers.In general, buyers of off-road recreationalvehicles have very different noiseconcerns than buyers of, say, automobiles.Many (not all) buyers of off-road vehiclesactually want as much noise as possible,or at least a lot more noise than manybystanders can tolerate. These buyershave a strong interest in the image of thevehicle, and noise plays an importantrole in that image. One could call this theHarley Davidson effect. Sound quality isimportant to buyers—they don’t want justany noise, but they often do want a lot ofthe kind of noise they enjoy.Factors that are critical to buyers ofoff-road vehicles include performance,handling, weight (which has a stronginfluence on both performance andhandling), image (in which noise playsa significant role), reliability, and cost.Secondary factors include durability andenergy efficiency. Most of the pressure toreduce noise in these markets comes fromregulators, who in turn are responding tothe involuntary listeners who go to openspaces in hopes of hearing peace andquiet, but who often are annoyed by offroadvehicle noise.Existing North AmericanRegulations:Snowmobiles meet a noise level on anacceleration passby test: SAE J192.The J192 test is used by the industry todevelop new machines and to demonstratecompliance with regulations. There isalso a simple stationary exhaust noise testdesigned to find user modified exhaustsystems in snowmobiles: SAE J2567. Thistest is aimed at detecting modified exhaustsystems and is used in locations such asnational parks to approve individual usersfor operation within a specified area.Off-road motorcycles are regulated by theEPA under CFR 40, Part 205, SubpartsD and E. These regulations apply to bothon-road and off-road motorcycles. Theregulations have been in place for about30 years, but the EPA office that enforcesthe rules closed in 1982. Manufacturersself-certify. ATVs are not regulatedin North America, but manufacturersgenerally meet the requirements formotorcycles, using the motorcycle testprocedure. There is also a stationaryexhaust noise test for motorcycles andATVs, SAE J1287. This procedure isaimed at detecting modified exhaustsystems, and is used to limit entry intomany sponsored off-road events, as wellas into certain parks and other areas. Eachindividual motorcycle is tested.102 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

Other off-road vehicles such as jet skis orultra-light aircraft face local regulations orno regulation. Typically these regulationsinvolve complete bans or restrictedoperating hours in specific locations.Primary Noise SourcesAll off-road vehicles share certain primarynoise sources: exhaust, intake, engineradiated noise, and chassis radiated noise.Additional sources for snowmobilesinclude transmission noise, track /suspension noise, and chain case noise(the power transfer unit between theengine and transmission). Track noiseis a particular problem on longer sledswhich are designed for deep snow, off trailoperation. For jet skis, the additional noisesources are pump noise and water flow /impact noise. The classic noise issue withjet skis is the sudden noise and changein noise caused by bouncing over waves.For off-road motorcycles and ATVs, theadditional noise sources are transmissionnoise, chain drive noise, and tire noise.Ultra-light aircraft noise sources includepropeller blade pass and airflow noise.Progress and Future Potentialfor Snowmobile Noise:Snowmobile manufacturers haveinvested significantly in noise reductiontechnology. Many of the software toolsand processes are similar to those usedin the motor vehicle and constructionequipment industries. Four stroke cycleengines are becoming more popular inorder to comply with exhaust emissionsstandards. Four stroke engines aregenerally quieter than the 2 strokeengines they are replacing. Moresophisticated intake and exhaust systemshave become common. These reducenoise, but increase weight and cost, anddecrease performance. Low noise intakeand exhaust systems also require morepackage space, which is at a premium ona snowmobile. Two cycle engines requirea tuned exhaust to achieve acceptableengine performance. Making a quiet tunedexhaust is a significant engineering andpackaging challenge. Barriers, damping,and absorption materials are used withinthe constraints of durability, coolingsystem performance, weight and cost.There is room for improvement in thetrack noise and in transmission noise.Unfortunately, the entire snowmobileindustry relies on one track supplier, socompetition does not help improve thebreed. There are also trade-offs betweentraction and noise, as there are with onhighwaytires.Snowmobiles suffer from a high rate ofcustomer modifications, estimated byindustry sources at 30% or more. Thesemodifications often include replacingthe exhaust system with a much loudersystem, which can exceed the factorysystem noise level by over 10 dB. Onlyfrequent enforcement testing in the fieldwill be able to reduce or eliminate thisproblem.One big issue faced by snowmobilemanufacturers is the variabilityinherent in the SAE J192 passby noisetest. Manufacturers report up to 6 dBvariability, depending on the conditionsof the snow and of the ground under thesnow. This makes it very difficult to haveany confidence in engineering tests aimedat optimizing a vehicle for low noise.The industry is working on a revision ofJ192 in an effort to improve repeatability,but even more improvement may berequired. One idea is to do noise tests onan artificial surface which would offersignificantly increased repeatability.Progress and Potential forMotorcycles and ATVsLike snowmobile manufacturers,motorcycle and ATV manufacturers haveinvested in automotive style technologyfor noise reduction. Aftermarketmodification is a significant problem,but not as widespread as the nearly100% modification rate seen for HarleyDavidson on-highway motorcycles. Theprimary reason is cost – dirt bikes andATVs are relatively inexpensive, butaftermarket exhaust systems are fairlyexpensive. Aftermarket exhaust systemscan increase noise by 10 dB or more. Thedevelopment and certification noise testprocedure used for motorcycles and ATVsis reasonably repeatable, unlike the casewith snowmobiles.The 4-Cycle Noise IssueFour cycle engines tend to be quieter, butthere is an issue with 4-cycle engines:low frequency exhaust noise. The firingfrequency of a single cylinder 4 cylinderengine operating at 6,000 RPM is only 50Hz, while a two cylinder engine at 6,000RPM fires at 100 Hz. Since all regulatedtest procedures use A-weighting, this lowfrequency noise does not need to be verywell attenuated. A-weighting reduces thenoise measured at 100 Hz by 19 dB, andat 50 Hz by 30 dB. Low frequency noisecan carry over long distances, makingannoyance at a considerable distance aproblem. Perhaps a loudness requirementwould be a useful tool for improving4-cycle engine noise. More work isneeded on this issue.Cultural IssuesThere are huge cultural and perceptionproblems involved in the noise of off-roadrecreational vehicles. The owners tend toregard high noise levels as a good thing(the “sound of power”). High noise levelsare even considered a safety factor bysome owners: “Loud pipes save lives.”Owners tend to think that louder andmore powerful go together. It is even alegitimate question to ask if the sales ofthese machines would be substantiallyreduced if the machines were quiet andnoise regulations were strictly enforced.Owners often fail to understand how theirlove of noisy machines leads to upsetneighbors and to restrictions on whenand where they can operate. Ownerswho use noise–compliant machines areoften punished with bans and restrictionsbecause of the actions of those who runmodified machines. The problem is notunlike the issue of “straight stack” exhaustsystems in the heavy trucking industry.The actions of the “cowboys” make life2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org103

harder for the industry, and for otherusers.When restrictions due to noise issuescome into effect, owners of off-highwayvehicles feel like victims. There is a veryemotional reaction about the eliminationof freedom, similar to the 2nd amendmentissues regarding any restrictions ongun ownership. On the other hand, theinvoluntary listeners can be very forcefulin demanding their peace and quiet.Vehicle owners often fail to recognizethat operating quieter vehicles is a veryacceptable common ground that wouldsatisfy nearly everyone. In the end, a lotof public education and enforcement atthe individual owner level is requiredin order to deal with this issue. There isno point in burdening the industry withmore stringent noise regulations at a timewhen many owners are modifying theirmachines in such a way that one modifiedmachine makes the noise of 10 factorymachines.Egons Dunens – Noisereduction at the source inofficesIntroductionThirty years ago typical office machinesincluded typewriters, adding machines,mechanical calculators, mimeographs andoverhead projectors in meeting rooms.Today these devices have been largelyreplaced by information technology (IT)equipment such as personal computers(PCs), printers and multi-function devices(MFDs), and digital projectors. So todayI’m going to talk about the progress madein reducing noise from four groups of ITequipment: 1) desktop PCs and notebookPCs, 2) workstations and servers, 3)printers and MFDs, and 4) digitalprojectors. MFDs can have scan, copy,print and fax modes.Desktop and Notebook PCsThe main sources of noise in PCs are fans,hard disk drives (HDDs) and optical diskdrives (ODDs). Fans generally provide asteady, broadband noise that may containtones at the blade passage frequency andits harmonics. HDDs have a tone at therotational frequency that may excite thepanels of an enclosure. As a result, a 7200rpm HDD has a tone at 120 Hz that mayradiate quite effectively even though thedrive itself is small. Some HDDs alsohave audible tones at high frequencies.ODDs will also cause the PC enclosureto vibrate especially during spin-up whenreading the media directory or whileperforming sequential reads. A 48X ODDhas a rotational speed of about 9700 rpm,so a harmonic series of tones spaced 162Hz can occur.The trade-offs for achieving a quiet PC arecost, thermal issues, and energy efficiency.Quieter components, sound absorbtivematerials, and exotic heatsinks all costmoney. The thermal designer would liketo run the fan(s) at a higher speed in orderto generate more cooling air for thermalmargin. But the noise produced by a fanvaries approximately by the fifth powerof the fan tip speed. A doubling of the fanspeed can result in a 15 dB increase inthe noise produced. But keeping the fanat a low speed can result in the processorrunning hotter, thus increasing the amountof leakage current and reducing theenergy efficiency of the unit.The tools for reducing the noise fromPCs include using 1) fan speed control,2) using quieter components, e.g. fans,hard disk drives with fluid bearings,3) improving the balance of rotatingcomponents, 4) using vibration isolationon fans, HDDs and ODDs, and 5)designing more efficient heatsinks so thatless airflow is needed.The demand for low-noise products comesfrom customers but is influenced by ecolabelsespecially in Northern Europe.The acoustic criteria in eco-labels such asBlue Angel and Nordic Swan have foundtheir way into bid specifications. Alsocustomers expect the next generation PCto be as quiet or quieter than the currentPC even though the new PC is morepowerful.The basic metric used by the IT industryis the sound power level in bels. Thestandards used include ISO 7779,ISO 9295, ISO 9296 and the Ecmacounterparts ECMA-74, ECMA-108and ECMA-109. ISO 9296 and ECMA-109 are the acoustic noise declarationstandards.Some PC data is presented from 1991where the average declared sound powerlevel was about 4.9 bels. The 2004 datashowed a reduction to about 4.0 bels to4.1 bels. The current average declaredsound power level of 3.8 bels correspondsapproximately to an operator positionsound pressure level of 28 dB. This is wellbelow typical low-noise office levels of35 dB to 37 dB. So quiet office PCs arecurrently available.Workstations and ServersThe factors for increasing the noise ofworkstations include: 1) more powerfuland multiple processors than desktop PCs,2) more HDDs and faster HDDs includingsome with speeds up to 15 krpm, 3)graphics cards (many with fans), and 4)higher wattage power supplies. Some ofthe same techniques that are used to quietdesktop PCs also apply to workstations.Additional techniques include: 1) usingmultiple fans operating at low speedsunder fan speed control, 2) using ductingto more efficiently direct the airflow, 3)using liquid cooling, and 4) using graphicscards that have thermal fan speed control.Servers present additional cooling andnoise control challenges because ofmultiple processors, multiple HDDs, andhigher component density particularly inlow-height rack-mount units. In additionto the previous noise control techniques,additional ones are using multiple thermalsensors to more accurately monitor thetemperature at critical locations and theuse of redundant power supplies.104 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

Printers and MFDsThe noise emitted by printers andMFDs has a more transient nature thanthe noise from PCs. The main noisesources include: 1) the paper transportmechanisms, 2) the print head andpositioning mechanism, 3) the scanner,and also 4) fans. The trade-offs forachieving a quiet printer include onesmentioned before: 1) cost, 2) thermals,and 3) energy efficiency. In addition, easeof use or easy access to various partssuch as the scanner platform is importantto the end user. In addition to L Wand L p,sound quality metrics are used especiallyto characterize the transient sounds thatcan cause annoyance. Besides objectivemeasures, such as loudness, sharpness,and roughness, jury testing is also used todetermine acceptable sounding products.ITI TC6 and Ecma TC26 conducted asurvey of printers in 2004. Slide 11 showsthe results for monochrome laser printersas a function of pages per minute (ppm)printed. The Blue Angel limit is also onthe slide. Most printers were at or belowthe Blue Angel limit line. Slide 12 addsprinter levels from my web survey ofrecent printers. The newer printers weresomewhat quieter than the original sampleof printers.Digital ProjectorsDigital projectors are used mainly inmeeting rooms as opposed in office areas.A bright light is needed for good imagequality on a screen, but also the lightcoming out of the projector chassis mustbe minimized in order to not distractthe audience. So, the heat from the bulbmust be removed while minimizing theopenings. In 2001, the declared soundpower level L WAdon several projectors wasdetermined to be between 4.8 B and 5.5B. The corresponding average bystandersound pressure levels L pAmrangedfrom 35 dB to 42 dB. The data on webspecification sheets typically only has L pAdata. Current values ranged from 26 dBto 37 dB with a cluster of units in the 30dB to 32 dB range. Most manufacturersdeclare dual values to indicate operatingmodes such standard / bright or standard /economy.Summary• IT equipment is commonly used inoffice environments.• The equipment has become muchquieter over time even though thecapabilities and performance haveincreased.• Consumers/users should match thedesktop PC to the environment inwhich the PC will be used.• The location in the office ofworkstations, servers and printersneed may need special attention. Thisequipment may need to be locatedin an area away from workers or theequipment may need to be placedbehind sound absorbing screens.• Projectors also should be matched fortheir intended environment.DiscussionDefeating Noise Reduction inWorkshopsQuestion: Is it common for operators todefeat noise control hardware/methodssuch as enclosures if inconvenience isintroduced?Answer: It is common for operators todefeat enclosures because of performance.Sometimes it’s because the noise controlsare designed without full considerationof the production requirements and tomake the job more efficient, because theoperator is most concerned about gettingthe job done and sometimes the noisecontrols get in the way. Sometimes thosecontrols are defeated. One way that thesuppliers and manufacturers have beenable to counteract that is to lock theenclosure such that the machine fails tooperate when the operator tries to defeatit. It’s a constant game of war betweenthe operators finding ways to be mostefficient and getting the job done and thecompromises that are introduced by theacoustical considerations. Sometimesnoise controls can affect the performanceof things like pneumatic valves. Someof the devices, mufflers especially thatare quite common for pneumatic valvetreatment, are removed because themachines will not cycle as efficientlydue to compressed air contamination.These are things that are part of routinemaintenance that are necessary toimplement.Comment: This is a very commonattitude.Comment: We did a study in amanufacturing company with very noisyequipment. The old-style equipment hadnoise levels that were in excess of 100dB continuous noise. Any noise controlefforts to quiet that equipment were oftendefeated because of the problems withmaintenance. These were all retrofit.The interesting thing is that this factorywas closed and the same equipment wassent to a different factory in a differentpart of the U.S. It was in Chicago andwas relocated to Nebraska. The sameequipment was sent to the Nebraskaplant, but in the process of doing so thecompany purchased total enclosures forthat equipment. It reduced the noise levelsto 45 dB; and any time the enclosureswere tampered with or removed, theoperators protested. So the operatorsenforced the noise control work becauseof the fact that the environment wasso different. It was what the operatorsbecame used to. In the first environmentnoise was common; in the secondenvironment noise was unusual.Comment: I think that you are remindingus of the human factor which is veryimportant.Focus on SourcesComment: Encourage the science ofacoustics to be focused on sources. Thispolicy can only be achieved with financial2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org105

support for relevant research. Themembers of CAETS academies shouldbe encouraged to give more preferencein education to the fundamentals insteadof the present, widely-promoted buildingacoustics. These education applicationsshould be focused on noise reduction atthe source and general acoustics.Comment: There are two responses tothis comment. The first one is researchfunding on source noise control. Thesecond one is developing a subculture forthe science of noise control. Wheneverthere is a noise or other new problem,management associates that withmalfunction; something has to be fixed.Noise control should be treated withfar more respect than it has right now.I think that’s part of awareness of thenoise sources. With our colleagues whoare in other disciplines—managers andothers—it should be emphasized thatnoise is often a multidisciplinary effort.It requires many different elements.We end up interacting with virtuallyeveryone whether it’s in the design ormanufacturing process, a cost reductionrequest, materials, and so on. You areconstantly meeting with different people,so I think we need to develop as positive asub-culture as possible.Centrifugal Blowers vs.Axial FansQuestion: Large equipmentmanufacturers are moving away frompropeller fans to centrifugal blowers.Centrifugal blowers offer a lot ofbenefits—lower noise, lower powerrequirements, and smaller openings.Why or when will other industries movetowards the use of centrifugal blowers?This is certainly true for earth movingmachines, for example, where it has beenproven that changing classical radial fansfor a more or less centrifugal systemwould enable a 4 to 10 dB reduction. Willit apply to equipment of the same type,which I think is the case, or to other typesof machines?Answer: As far as centrifugal blowers,they are used in some cases. But a lotof times the geometry limits their use.A form of that type of fan is used inworkbooks just because it is flat. Intelhas some presentations showing whatthe effect of inlet restriction is on blowerperformance. The blowers have beenused on some heat sink fans, but in othersituations, the geometry of the systemlayout is not conducive to that type of fan.Some of the larger products, such as somenetwork boxes that hold multiple storageunits, do use blowers. So it’s a matchbetween the performance requirements ofthe system and the type of blower or fanused.Comment: In the heavy truck andconstruction equipment world, the layoutof the engine compartment and coolingsystems is not conducive to blowerssimply because it would require extensivere-design of the machine. It would be asituation where a centrifugal fan could beused if you are designing a new machinefrom scratch and you decided up frontyou wanted to implement a new coolingdesign. It would be very hard to retrofitan existing machine. In the heavy truckworld this wouldn’t happen. In fact, inheavy trucks you tend to rely a lot onintake air, so the amount of time the fan isrunning is relatively limited. And as theyget smarter with controls, it will becomeeven more limited in the future.Comment: To address your point, in newproduct design at Ingersoll Rand we arenow using centrifugal blowers. What wehave found is that to be successful wehave to change the housing to gain highstaticpressure. With the blowers there isa steady flow, they can blow at a specificspeed, and when you do that you can geta significant amount of sound reduction.How much reduction? About 5 or 10 dB.Overall, centrifugal blowers seem to bethe best way to go; but you have to startwith a new package design. You can’tretrofit.Comment: Improved performance ofCPUs in the last year is incredible. But ina typical office you don’t need this. Theperformance of the CPU is so high thatyou will never find a situation where youreally need it.Keyboard NoiseComment: I have not tested anykeyboards lately, but there has beensignificant progress in keyboards.Keyboards have become much of acommodity lately. One of the driversis cost. About 15 years ago whenpeople were making the transition fromtypewriters to keyboards, they liked tohave feedback when striking a key. That’swhat they’re used to hearing. Regardingkeyboard noise, there are some keyboardsthat are fairly quiet, but manufacturershave them produce an audible click sothat the person typing realizes that thekey was registering. In some cases thesound actually comes through a smallspeaker. This is fine for the user but notfor the bystander. There are a number ofthings that can be done. You can controlthe sound the key makes on the downstrokeand when the key comes back toits original position. Some of the largerkeys like the space bar may have a springor leveling bar that control how it sounds.My personal keyboard tester is my boss.He has big hands and attacks the keyboardquite aggressively. It’s difficult to do asound power measurement; you almostneed to have a typing robot in order to doa sound power measurement.Comment: Or people who are familiarwith typing, like secretaries. If you choosea student and he uses only two fingers,is it quite noisy on such a keyboard. Wecompared this with the robot systemwhich was developed many years ago.The result is different depending on theuser, the normal person who types on sucha keyboard. It’s not easy to design a goodrobot. The results you get from personswho are typing need to be compared.Comment: An excellent paper on106 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

keyboard noise was presented bycolleagues three years ago at the IstanbulINTER-NOISE. Our experience manyyears ago was that you can get repeatablemeasurements in the laboratory if you’reusing consistent force. That’s what therobot is intended to do. However, inactual use I think we’ve all observed thatthe real source of the noise is the handthat is typing. There are some peoplewho pound away. Many years ago duringthe typewriter studies, IBM wanted theoperators to be able to understand thatthey made contact. In addition to thepsychological factors a feeling that oneis making contact is important. It’s asimple thing to reduce that noise. There’sergonomics involved to make sure you aretyping properly. I would also like to notethat the comment about fan noise is notmuch of a problem for today’s PCs.The Future of PCsQuestion: I have a question regardingnotebooks or PCs. In the future it wouldseem that these devices—notebooks—could be totally silent. What are youexpecting?Answer: Currently my company notonly makes business desktop PCs, butalso products for clients that are basicallypassive systems and work over thenetwork with the servers in a remotelocation. However, the need for coolingfans will not go away. As long as youhave devices that consume power, youhave to get rid of the heat. There’s a classof desktop PCs called Ultra Slims that inthe last few years have become almostlike notebooks. They use a power brick.There are many local printers that willnot have a power supply; they’ll havea brick that is the power source. Usinga brick removes one noise source. Butyou still have memory chips and CPU’sthat use more energy and run faster. Oldmemory sticks used to be measured inkilobytes but now they are measured inmegabytes. These devices need moreenergy and that produces more heat. Theneed for fans will not totally go away.As far as using cloud computing, I’mnot sure I want all my personal data ona remote server. There are articles about130 million personal identification itemsbeing stolen by hackers. How muchcontrol over your personal informationdo you want to relinquish? In a businessoffice where the employer is in control,the manager can dictate whether one hasa personal computer or a remote terminal.Twenty years ago people were used tothe mainframe computer and terminalmodel, so there is a trend to go back to adumber or less powerful local device withcontrol of the software at the server. Froma computer IT management perspective,it’s convenient to have all the software anddata on small servers or on blade serverswhere they can be easily serviced. All thesoftware updates can be controlled andaccess to the servers limited. But there’salso a certain amount of human resistanceto this perspective.SESSION 3:Building NoisePanelists• J. David Quirt, NRC, Canada, SessionChairOverview of building noise• J. David Quirt, NRC, CanadaNoise transmission in commercial andresidential buildings• Laymon Miller, Consultant, U.S.A.System approach to the control ofnoise and vibration in buildings due toservice equipment• Ralph Muehleisen, Illinois Institute ofTechnology, U.S.A.Noise problems and opportunities in“green” buildings• Birgit Rasmussen, Danish BuildingResearch Institute (presented by DavidQuirt)Noise limits and building codes• Brandon Tinianov, Serious Materials,U.S.A.Sustainable materials and newdevelopments for building noisecontrolPresentationsJ. David Quirt – Overview ofbuilding noiseNoise impacting the occupants ofbuildings comes from several typesof sources. Quieting the source isfeasible in some cases, but control ofthe transmission path to receivers is alsocommon—and is the only option for somesources.• For major outdoor sources (traffic,railways, aircraft, industry) noisecontrol combines source emissionlimits with land-use planning andbuilding adaptation to reduce noisepenetration.• For building services (HVAC,plumbing, elevators, etc.) noisecontrol involves components’ noiseemission and the control of air-borneand structure-borne transmission toadjacent spaces.• For occupant appliances (dishwashers,laundry appliances, etc.), productsthat are quiet from the user’sperspective have been developed andmarketed. Prediction of structurebornetransmission to adjoiningoccupancies is feasible for some typesof construction, but data on vibrationfrom appliances is limited.• For noise from neighbors (voices,audio systems, footsteps) noise controlfocuses on the transmission path, vialimits on air-borne and structure-bornetransmission to adjacent spaces.International harmonization of technicalstandards for measuring noise in buildingsis limited—ASTM procedures are used inUSA and Canada, but ISO procedures areused or are the basis for national standardsin most other countries.2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org107

• Most ASTM standards for assessingsound transmission in buildings havenear-equivalent ISO counterparts, butthey differ in terminology and somedetails of testing procedures.• ASTM standards for speech securityand sound in open plan offices haveunique features.• Many new ISO standards have noASTM counterparts, especially in thecontext of structure-borne flankingtransmission, auditorium acoustics, andnew measurement techniques.Metrics for noise heard by occupants ofbuildings exhibit even more variety thanthe limited harmonization of ASTM andISO measurement procedures.• For sound transmission throughseparating wall or floor assemblies,ASTM and ISO have near-equivalentmetrics for sound from air-bornesources (STC and R w) and footsteps(IIC and L nw).• For sound transmission betweenadjacent spaces in buildings, includingall transmission paths, ASTMestablished ASTC, NIC and NNIC(which have different normalizationto allow for room absorption). ISOstandards give four variants forabsorption normalization and foreach of these offer four choices forfrequency-weighting; one subset ofthese resembles the ASTM metrics.• For these metrics for sound insulationbetween adjacent spaces, recentresearch studies show that none of theASTM or ISO frequency-weightingalternatives is a significantly betterpredictor of listener reaction for allcommon household sounds, thoughsome are marginally better for specificsources. (See Park and Bradley, JASA,July & Sept. 2009.)• There are similar sets of metricsin ASTM and ISO standards forinsulation against outdoor noise andfor noise from footstep impacts.• Rating the impacts due to “childrenjumping” and the low frequency“thumping” due to adult walkerson lightweight floors may requireadditional measurement proceduresand/or metrics. The “heavy/softimpact” test method and metric innational standards for Japan and Koreamay satisfy this need, but furtherresearch is needed.Regulating Noise in Buildings• National building codes defineminimum standards for acceptablebuildings. Regulations alone are notwell-suited to provide good noisecontrol. Labeling schemes to marketbuildings with superior noise controlgive a useful extension beyond codes.• The lack of “harmonization” ofEuropean descriptors in ISO 717enabled a proliferation of uniquenational regulatory criteria usingdifferent metrics (which inhibitscomparisons and international trade).• Science-based re-evaluation of theavailable metrics is needed to providean objective basis for convergence ofinternational consensus to a justifiablesubset of the current array of nationalregulatory criteria for both airborneand impact sources.Classification Schemesfor Rating (and Marketing)Buildings with Superior NoiseControl PerformanceClassification schemes have beencreated as national standards in manydeveloped countries. Like the regulatoryrequirements, they use a variety of metricsand have nationally-chosen requirementsto categorize performance into severalclasses that exceed the basic regulations,to provide a framework for marketingsuperior buildings.In all cases, these classification schemesinclude criteria for insulation againstairborne and footstep noise fromneighboring dwellings, many includeinsulation against outdoor noise sourcessuch as road traffic, and some includecriteria for noise due to building services.No corresponding national standards havebeen developed in USA or Canada, butextensive studies of occupant preferencesin Canada suggest a similar framework iswell-suited to the North American market.Developing rational internationalconsensus within technical communityoffers an opportunity to go beyond theminimum requirements, to facilitate betterindoor environments.Summary of Key Needs(which are explained in moredetail in the subsequentpresentations)• Key areas for further research anddevelopment include:• extensive human response studies tovalidate selection of an optimal subsetfrom the proliferation of metrics fortransmitted sound of all types (airbornesources within buildings, outdoorsources, footstep sound includingadults walking or children running)• studies to establish the effect ofsurface mobility on transmission ofvibration and impacts from footstepsand appliances• credible sources for comprehensiveand periodically-updated data on theperformance of specific subsystems(such as floor coverings or ceilingassemblies) on airborne and structurebornetransmission of sound inbuildings (preferably with genericdescriptions)• In the context of standards andregulations, key objectives include:• Consensus on an optimal subset ofmetrics for insulation against key noisesources• Harmonization of ISO and ASTMstandards for measurement andprediction of transmitted sound, andextension of the prediction methods tolightweight constructions.• Common labeling schemes forbuildings to supplement regulations by108 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

facilitating marketplace differentiationof superior noise control performanceJ. David Quirt – Noisetransmission in commercialand residential buildingsFor airborne sound sources (voices,TV, home theatre, etc.), the soundtransmission rating for the separating wallor floor-ceiling assembly provides a firstapproximation to the noise transmissionbetween adjacent occupancies (side-bysideor one-above-other) in a building.• Extensive parametric studieshave established credible data fortransmission through most commonwall and floor assemblies, describedin terms of generic properties ofcomponents and assembly details.Some manufacturers publish data forassemblies with specific proprietarycomponents. Data are scattered amongmany sites, each with informationpertinent to constructions typical in alimited region. There are concerns thatpublished data become misleading asproducts change, but the underlyingtechnology is well-established.• ASTM standards for laboratoryand field measurements are used inCanada and USA; the resulting soundtransmission class (STC) rating isnormally quoted; corresponding ISOstandards and ratings are used inmany other countries. Terminologyand technical differences between theASTM and ISO standards are of minortechnical significance.In all buildings, more sound is transmittedbetween adjacent spaces than one wouldpredict from the rating for the separatingwall or floor assembly; in some cases thisdiscrepancy is large.• Sound isolation between adjacentspaces is systematically lower thanone would predict from the STCrating for the separating partition,due to structure-borne (flanking)transmission of vibration energy viaother room surfaces. ASTM standardshave several measures such as theapparent sound transmission class(ASTC) to characterize this overallsystem response; similar ISO standardsand ratings are used in many othercountries.• Construction errors or leaks can alsoreduce performance (and are includedin ASTC).• Building codes in Canada and the USAfocus on the rating for the separatingwall or floor—as if this were theonly transmission path—and mostdesigners and regulators in Canadaand the USA were trained withthis simplistic perspective. In otherdeveloped economies, standards andregulations use ISO ratings of systemperformance that (like ASTC) includeall transmission paths and hencerelate to what occupants actually hear.There are large variations in nationalregulatory and design requirements,but little technical justification forthese differences.For impact sound sources (footsteps orchildren running and jumping), there isalso noise transmission between adjacentoccupancies (side-by-side or one-aboveother)in a building.• ASTM standards for laboratoryand field measurements are used inCanada and USA; the resulting impactinsulation class (IIC) rating is normallyquoted; corresponding ISO standardsand ratings are used in many othercountries primarily using the L nwrating (which is closely related to IIC).Terminology and technical differencesbetween the ASTM and ISO standardsare of minor technical significance.There are large variations in nationalregulatory and design requirements,but little technical justification forthese differences. Existing ASTM andISO ratings do not deal suitably withlow frequency “booming” sounds fromlightweight floors.• Most designers and regulators inCanada and USA focus on the IICrating for the separating floor, as if thiswere the only transmission path. Inother developed economies, standardsand regulations use ISO ratings ofsystem performance, like Apparent-IICwhich includes all paths.• Extensive parametric studies haveestablished credible ratings for manycommon floor assemblies, describedin terms of generic properties ofcomponents and assembly details.• To assess improvements due to addedfloor coverings or the low frequencysounds from adults walking or childrenrunning (especially for lightweightconstructions), additional research andenhanced testing methods are required.For buildings with concrete and/ormasonry structure, the science and theengineering tools for predicting theoverall sound transmission betweenadjacent spaces are well-established.• A full set of ISO standards to supportsuch predictions have been established:• Conventional testing using ISO 140series (now morphing into new ISO10140 series) gives data for directtransmission through separatingassemblies.• Other parts of the ISO 140 series ofstandards and the ISO 10848 seriesgive estimates of flanking transmissioninvolving other subsystems.• ISO 15712 series use results from theabove tests on subsystems, in a wellvalidatedSEA calculation of systemperformance (including the combinedeffect of direct and flanking paths, forboth airborne and impact sources).• Commercial software packagesimplementing such calculations areavailable.• ASTM standards include only a few ofthese procedures.For buildings with lightweight framedconstruction, the basic science is well-2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org109

established, but more research anddevelopment is required.• Lightweight construction is a large(and growing) part of multi-familyhousing market for smaller buildings,especially in North America.• Sound transmission in lightweightframed buildings is not predicted wellby ISO 15712 approach.• Extensive experimental studies inCanada have established suitableevaluation and calculation methods,and documented typical performancefor most common wood-framedconstructions.• Knowledge gaps remain for someconstruction types, such as lightweightsteel-framed construction orlightweight constructions combinedwith masonry and concrete assemblies.• Software tools and data for morevariants of lightweight constructionare under development, but to advancethis into common engineering practicethere will be a need for both furtherevaluation of common types ofconstruction, and adaptation of thetechnical standards such as ISO 15712and its supporting subsystem tests.For office buildings and for publicbuildings such as courts and hospitals,there are similar technical concerns, oftenexpressed in terms of speech privacyrather than noise.• Criteria and procedures focus onspeech intelligibility appropriate inspecific contexts:• Ensured speech security for spacesused for confidential legal or healthrelateddiscussions can be handledusing the new ASTM E2638 standard• For open plan offices, a series ofASTM standards address speech“privacy”• Some of these issues are alsoaddressed (with minor differences) inISO standards.Summary of key needs:• In the short term, key areas for furtherresearch include:• extensive human response studies tovalidate selection of an optimal subsetfrom the proliferation of metrics fortransmitted sound of all types (airbornesources within buildings, outdoorsources, footstep sound includingadults walking or children running)• data for flanking transmission andfor improvements due to added floorcoverings, with emphasis on lowfrequency performance and lightweightconstructions• In the longer-term context of standardsand regulations, key objectives include:• extension of standardized predictionapproach (like ISO 15712) applicableto both heavy and lightweightconstructions, with sufficient accuracyfor design approvals• harmonization of ISO and ASTMstandards for evaluating and predictingnoise in buildingsLaymon Miller – Systemapproach to the controlof noise and vibration inbuildings due to serviceequipment (Part 1)With a system approach to noise controlin buildings, we expect to do the jobright the first time. This is by far the leastexpensive approach. I suggest nine stepsin a total approach; there are concernsabout all nine, but Steps 3-6 are theacoustical ones that we will pursue here.1. Recognize the problem.2. Identify the noise source(s).3. Obtain noise data for the source(s).4. How much noise is acceptable ?(introduce "noise criteria")5. The noise reduction required, indecibels.6. Determine the noise controltreatment(s).7. Produce drawings, specifications;communicate with everyone8.9.involved.Purchase and Install the desiredtreatment(s).Check Installation for acceptableperformance.Step #3.This discussion is essentially limitedto noise; the talk that follows willconcentrate mostly on vibration. In theprepared talk, a representative mechanicalequipment room (MER) of a largebuilding was used as an example. Typicalpieces of mechanical and electricalequipment were positioned in the room,and known or estimated noise levelswere included for the equipment attheir operating conditions. At this point,reliable noise level data are required;these data should be obtained from theequipment manufacturers or they shouldbe measured or estimated or obtainedfrom a known reliable source. In my ownwork over the years, I accumulated largequantities of this kind of information.In the geometrical layout of this particularproblem, I envisioned that the MER wasenclosed in a solid wall of sufficientsurface weight to keep the escaping noiseacceptable for the area outside the MER. Ina typical MER, massive (not light-weight)walls are a known requirement. I startedwith an 8-inch thick solid–core concreteblock wall. Again, in my own work, Ihad determined (by measurement orcalculation or literature search) the “soundtransmission loss” (TL) of practically everyconceivable type of wall (or floor-ceiling)combination. For more complicatedgeometries, an MER might be locateddirectly above or below an office, in whichcase data for an acceptable floor-ceilingstructure would also be required and used.In this particular example, the total noiselevels inside the MER (impinging onthe room walls) were determined. Then,applying the TL of the selected wall, weobtain the noise levels outside the MER inthe adjoining area. In an actual situation,a term “Noise Reduction” (NR) is more110 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

appropriate; it includes the TL of theselected wall plus a correction term thattakes into account the area of the wallbetween the MER and its adjoining space,as well as the acoustic conditions of the“receiving room” that receives the noisefrom the MER. Refer to a textbook insound for the details of this calculation.Step #4.This step introduces “Noise Criteria” or“Noise Criterion Curves” (NC Curves, wecall them). There is a large collection ofdata and studies by Dr. Leo Beranek andothers who have measured the backgroundnoise levels in all kinds of occupiedspaces, and categorized those noise levelswith the kinds of spaces where theyare typically found – thus giving riseto the term “NC Curves” of noise. Thisthen allows us to permit new intrudingnoise sources to make noise that can besomewhat immersed in the noise thatis already present, and pass essentiallyunnoticed. This assumes that the newnoise is fairly indistinguishable in its ownsound character. NC Curves are typicallyidentified by number, such as NC-25, NC-30, NC-35, and so on upwards to aboutNC-65. Background sound levels as lowas NC-15 are often desired for fine musicor concert halls. NC levels are found inmost current text books on sound.Step #5.Taking the numerical difference (indecibels, in the different octave frequencybands) between the total noise levelsinside the MER and the desired noiselevels outside the MER in order to meetthe Noise Criterion for that space, we havethe “Noise Reduction” (NR) required forthe wall and wall geometry.Step #6.With the “Noise Reduction” determinedin Item #5 above, we confidently selectthe wall material and surface weight thatwill satisfy the NR requirement. It was onthe basis of that kind of calculation that an8-inch concrete block wall was selectedfor our example MER.For an occupied office (with its lowerNC Curve) directly under the MER, wewould have a more difficult floor-ceilingstructure, but it is done all the time---with special care and probably a heavierconcrete floor slab and thicker ceilingthan normally used. It is quite possiblethat the ceiling would be of 2-inch thickplaster, and resiliently supported under thefloor slab of the MER (to have a typical“double-wall construction”).If still more noise reduction is required,it may be necessary to specify quieterequipment in the first place, or have aheavier wall with a higher TL, or applymore sound absorption material in theMER or in the “receiving space”, or itmight be preferable to apply some sortof noise control treatment to the specificpiece of machinery that is making thedominant noise in the MER. These areall available as noise control treatments,and it often requires a special finesse toknow and design the best treatment for thespecific problem.Of course, for this discussion, avery simple example was selected.The problems are usually a lot morecomplicated and the treatments requiremore complicated solutions.In the prepared talk, I also included fannoise as a major problem in the ventilationsystem of buildings. This involves a morespecific noise analysis as there are severalnoise sources (in addition to fans) in atypical ventilation system and there areavailable noise control treatments in thesystem as well. ASHRAE articles anddata books and “Handbooks of NoiseControl” provide data and procedures forcalculating noise and noise control forfans and ducted ventilation systems.Elevators and escalators are sometimesconsidered to be noise and vibrationsources. For safety reasons, elevatorinstallation specialists do not wantresilient vibration-isolation mountingsfor any of their equipment, so the bestnoise control treatment is to surroundelevator shafts with non-critical areas,such as corridors and non-critical workspaces. Escalators most often are locatedin expansive and somewhat noisy publicspaces and usually do not representnoise or vibration problems. I have neverhad an escalator problem, and hence nosuggestions.The wide variety of mechanical andelectrical equipment and locations inmost buildings, and the wide variety ofNC conditions that might be applied intheir adjoining areas, make it difficultto anticipate setting noise and vibrationstandards and writing performance codesfor their universal uses in widespreadapplications. Consider the followingtypical equipment, some of which arefound in almost all large buildings:fans, pumps, motors, motor-generatorsets, air compressors, large refrigerationcompressors, packaged chillers,reciprocating engines, gas turbine engines,diesel engines, boilers, transformers, andcooling towers.In earlier years, I gave short lecturecourses around the U.S. and Canadaon noise control, and it took three daysto discuss this material. The LectureNotes had 155 Tables of Data and 87Figures of Details. It may take a greatdeal of time, patience, and ingenuity tocompress that diversity of data, material,and applications into practical codes andstandards.Laymon Miller – Systemapproach to the controlof noise and vibration inbuildings due to serviceequipment (Part 2)In our above discussion of the "SystemApproach," we concentrated on noisecontrol. Now, we have the more seriousproblem of vibration control—mostlyfrom the same kinds of equipment.Let's assume that it is in the mechanicalequipment room right over our heads.2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org111

Here we want to control both the feelableand the audible aspects of vibration; .. . and the real problem is that usuallywe can still hear the structure-bornenoise long after we can no longer feel itsvibration.For vibration control, a suitable vibrationisolation mount is installed between theequipment and the floor that it is sittingon -- or whatever surface that it mightbe setting into vibration. We will reviewonly the most basic of fundamentals,....asvibration relates to noise; and we will betalking about steel springs and neoprenein-shearas typical isolators. At the end,air springs will be mentioned.This is not a theoretical paper, but thereis one equation that is essential to keep inmind:f n= 3.13 x square root of 1/ S.D. Hzwhere f nis the natural frequency of thevibration isolation mount (steel spring orneoprene-in-shear) and S.D. is the “staticdeflection” (in inches) of the mount when itis loaded. As a simple example, if a springis loaded with a 350-lb load and the springcompresses 2 in., the natural frequency ofthe mount with that load is about 2.2 Hz.Now, we must be certain that the “drivingfrequency” of the mounted machine doesnot equal (or come anywhere close) to thatnatural frequency. If it does, the systemmay go into serious vibration and couldeven damage the device. In fact, for “good”vibration isolation, the driving frequencyshould be at least 6 to 10 times the naturalfrequency of the mount, and preferablyup to about 50 to 80 times the naturalfrequency for really important installationsand situations.In machines such as fans and pumps,for example, the RPM of the machine isusually the lowest driving frequency but itis not the most serious source of vibration.Usually, the blade- passage frequency isthe more important source of vibration.As a simple example, suppose we havea 900-RPM fan with 10 blades, and thisis mounted on springs that compress 2in. under the load (with 2.2 Hz naturalfrequency, as mentioned above). The fanthen has a driving frequency of 900/60RPSec = 15 Hz and the fan bladesprovide a driving frequency of 10 x 15= 150 Hz. The 15-Hz driving frequencyfor the fan RPM is about 6.8 times thenatural frequency of the mount, and thatis acceptable for RPM vibration. The150-Hz driving frequency for the bladepassages is then about 68 times the naturalfrequency of the mount, and this willprovide very good vibration isolation – ifevery thing else is done properly.When mechanical equipment rooms arelocated directly over or near offices orconference rooms or other relativelyquiet spaces, it is often necessary to goeven further in providing good, completevibration isolation. One step is to mountthe vibrating device on a heavy concrete“inertia block” (usually in the form of aslab under the fan-and-motor or pumpand-motor),which should have a mass ofat least 5 or 6 times that of the vibratingload (even larger for a reciprocatingdevice). Then, the vibration isolationmounts should be located at the outercorners or edges of the inertia block,preferably as far as possible horizontallyfrom the center of gravity of the totalassembly (including the concrete block)and as nearly as possible in a plane thatcontains the vertical center of gravity.Many vibration isolation manufacturersalso have a line of metal forms forconcrete inertia blocks for practically anysize desired, and they can be deliveredto the job for concrete filling. In theprepared talk, slides were shown for thesevarious components of standard vibrationisolationmounting systems.In very special noise-control problems, itis often necessary to have a large clearance(2- to 4-in.) under large-area concreteinertia slabs so that there is minimum “aircoupling”between the bottom of the inertiablock and the floor slab under it – not tomention that the larger air space reducesthe possibility of building trash beingswept under the block and causing a shortcircuitin the isolation system.Ducts and piping connected to thesemajor vibrating systems also conductvibration, and must be provided withproper protection. Typically, vibrationisolatingceiling hangers or floor-mountedvibration isolation mounts can providethis necessary added protection; andthese should be used for large distancesfrom the actual equipment. Pipes conductvibration along their pipe walls; so,reinforced neoprene pipe connections andexpansion joints are also a requirement,especially for large piping. They shouldbe installed in the piping very close tothe vibrating source. Piping still carriesvibrational energy in the liquid insidethe pipes; and it is important to keep itaway from rigid contact with buildingstructures. So these pipes must becarefully isolated from building floorsand walls – to prevent “structure-borne”noise transmission. Vibration isolationmanufacturers can provide all sorts ofthese isolating and mounting devices.Electrical conduit connected to vibratingequipment should be of flexible armoredcable for a short distance or have one ortwo large circular loops that help absorband reduce vibration transmission.In residential situations, if plumbing noiseis a problem, pipes should be wrappedwith several layers of 2-inch-widefiberglass cloth tape, to build up to about1/4-inch thickness, and that wrappedportion attached to the wall under a pipeclamp. A ribbed neoprene pad wrappedaround the pipe and clamped, might do aswell. Also, if water faucets squeal whenthey are turned on, the water pressuremight be higher than necessary, andperhaps the squeal can be reduced with apressure regulator valve.On the subject of ceiling hangers, hereis a very essential application; this wasmentioned in the earlier talk on noise.112 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

When a quiet space is located directlyunder a known noisy area, it is oftennecessary to install a heavy ceilingsuspended on resilient ceiling hangers tohelp reduce the noise from that overheadspace. A 2-in. thickness of plaster or twoor three plies of dry-wall gypsum boardwill often serve this purpose. In effect,this becomes "double-wall construction",with the overhead floor and the heavyceiling serving as the two members of the"double-wall" system.We are not structural engineers, but formechanical equipment rooms or floors, werecommend dense concrete and large floorthickness in order to provide a massive,rigid base for supporting all of thisequipment and its concrete inertia blocks.Where there are large spans betweencolumns, floor deflection becomes afactor, and the vibration isolation mountsmust have even larger static deflections.When vibrating equipment is mounteddirectly on the floor or on steel springsdirectly over quiet spaces, the metalto-floorconnection can transmit highfrequencystructure-borne noise. Ribbedneoprene pads and waffle-patternneoprene pads may be placed under thefoot of the equipment or under the baseplateof the springs to help in reducinghigh-frequency noise transmission.If you ever bounced up and down on aninflated automobile inner tube, that was anair spring. (Do you even see automobileinner tubes any more?) Technically, airsprings are much more sophisticatedand can handle heavy loads with highpressure air. When designed and usedproperly, they are very good and servespecial purposes. Slides (borrowed fromEric Wood at Acentech, Inc.) showedtwo large, massive concrete inertiablocks installed on air springs to isolatetest beds from nearby earth-borne orstructure-borne vibration. One particularair spring (by Kinetics Noise Control) wassupporting a 60,000-lb load with a naturalfrequency of 1.25 Hz.Several years ago, I had at least threeproblems that required a vibration-isolatedbase (but not nearly as large and heavyas the inertia blocks shown in Eric’sslides): one was in a medical universityrequiring a vibration-free mounting for anelectron microscope, one was for a massspectrometer in an industrial process, andone was for a space-age inertial guidancesystem. In the first two, before the isolatedbases were installed, a banging dooranywhere in the building could ruin theirreadings.Large roof-mounted cooling towersfrequently have so much vibration causedby their propeller fans, that they causeserious vibration in their own buildings. Inthe prepared talk, I showed slides obtainedfrom Reggie Keith (of Hoover & KeithInc, in Houston). In his "Method 1", thewhole tower is vibration-isolated withlarge steel springs. In his “Method 2”, thepropeller fan and its drive motor and gearare isolated from the cooling tower proper.Reggie even sent me one slide that waslabeled "Very Old Example of Method 2".It was a photo of one of my jobs about 50years ago. Whether it is Method 1 or 2, ifthe cooling tower is located immediatelyabove office spaces, it is essential thatstacks of ribbed neoprene pads be used tohelp reduce the higher frequency noise ofthe waterfall into the basin.I would like to mention two important,"do's" and "don't's" on the subject ofvibration isolation. First, "DO" design theinstallation so that you can clearly see theisolation mounts. If they are hiding andyou can't see them, you may not knowwhether they are working properly ornot. My second "DO" is this: If springsare to be used, "DO" use unhoused,free-standing springs. Some springs arecontained in housings, and there is only asmall slot in the side of the housing to seethe spring inside. If the spring is tiltingsidewise, it might be scraping on theinside of the housing and not performingat its best. The manufacturer knows thatthis might happen, so pieces of rubber arelocated inside the housing, so the springrubs against rubber pads. This, too, canreduce performance. It is best to avoidhoused springs.There are three other possible noise andvibration problems in buildings that couldbe considered, but there is not enoughtime here.1. Floor-to-floor impact noise in multifamilydwellings. There are available"floating floor" designs for bothwood and concrete floors that can beapplied to buildings either before orafter they are built.2. Service equipment such as elevatorsand escalators. Mentioned briefly inthe first talk on noise.3. Protection of buildings from earthborneor structure-borne vibrationcaused by nearby railroads, subways,and highways. I have workedsuccessfully on a few of these, butthey are major problems and requiremore discussion than available here.The same applies to an even greaterextent for protection against seismicdisturbances, such as earthquakes.The material presented here is based onmany experiences gained as an acousticalconsultant to architects, engineers, civicgroups, building owners, manufacturers ofacoustical products, and other interestedgroups. And, the problems and treatmentsnamed here are among the simplestones. We must often be detectives tofind the real cause of a problem. Thereis such a wide variety of equipment andapplications, I believe that acousticalconsulting represents an essential part ofengineering and architecture.My two discussions of noise and vibrationof building equipment do not address theproblem of producing applicable noisecodes and standards. However, they dohighlight the wide range of equipmenttypically used in most large buildings (andin many smaller buildings) and the various2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org113

locations that might require a limit on therelative acceptance (“noise criteria”, asdiscussed briefly) of intruding noise intothe environment. This emphasizes theproblem of detailing codes and standardsfor this wide variety of noise sources andlocations. It is my opinion that this willrequire large amounts of time and infinitepatience. I offer my thanks and gratitudeto those who can accomplish this.Ralph Muehleisen – Noiseproblems and opportunities in“green” buildingsWhat is a “Green” Building?“Green” buildings are supposed to bebetter for the environment (i.e. moresustainable) than conventional buildings.During construction and operation theyuse less energy and water and destroyless of the environment. They should alsoprovide a better indoor environmentalquality (leading to better workersatisfaction and performance).Why are “Green” BuildingsDifferent?Green building design aspects focus onenergy use, water use, and sustainablematerials. They make optimum use of:• Natural ventilation• Daylight and passive solar heating• Radiant heating/cooling• Wood and stone and less use offiberglass or mineral fibers• Glass for daylight integration andviews of the outside worldGreen buildings also use fewer interiorwalls and partitions.LEEDLeadership in Energy and EnvironmentalDesign (LEED) rating systems have beendeveloped by the U.S. Green BuildingCouncil (USGBC) which is the mostpopular green building rating system inthe U.S. Other rating systems includeGreen Globes and Build it Green. LEEDhas different rating systems for thefollowing different types of buildings:• New construction• Existing Buildings / Operation andMaintenance• Core/Shell + Commercial Interiors• Schools, Healthcare, RetailAcoustics in LEEDOnly LEED for Schools and the soon tobe released LEED for Healthcare haveany acoustics. The LEED for Schoolsrequirements are a reduced version ofANSI S12.60 Classroom acoustics, andthe LEED for Healthcare requirementsare a reduced version of the acoustics inAIA Guidelines for Healthcare Design.The most popular LEED rating systems(NC and EB/OM) have no acousticswhatsoever. As a result, design teams haveno incentive (from the rating system) todesign for good acoustics or even considerthem within the design phaseSurveys of BuildingPerformanceA survey was conducted of more than400 buildings that included LEED-rated”green” buildings and new non-greenbuildings. The questions asked dealtwith acoustics, thermal comfort, airquality, lighting, cleaning/maintenance,office layout, and overall workspace.Acoustics is the only category wherethe performance significantly decreasedcompared to non-green buildings and itis the category with the lowest ratings.In short – “green” buildings have worseacoustics.Acoustics ComplaintsThe major acoustic complaints in LEEDrated“green” buildings concerned peopletalking in neighboring areas, peopleoverhearing private conversations, andpeople talking on the phone. Ringingtelephones were a lesser complaint. Therewere minor complaints about mechanicalnoise (heating, cooling, and ventilationsystems), office equipment noise, andoutdoor traffic noise.Causes of Poor AcousticsIn “green” buildings there are severalcauses for poor acoustics. These include:Natural ventilation. Natural ventilationuses small room-to-room pressuredifferences to drive air flow throughholes in walls and open windows. Thisreduces the energy use to draw and moveair in ducts and provides higher qualityair to occupants. This results in reducedHVAC noise which can be good but cansometimes be so quiet as to reduce speechprivacy. It also results in poor soundisolation from outside to inside and roomto room with lower cubicle wall sizes.More use of daylight and passive solar.Green buildings use a lot more sunlightfor illumination (day lighting) and heating(passive solar). More sunlight meansmore windows and some use of glassfor internal walls to allow more interiorsunlight penetration. As a result there isreduced indoor/outdoor sound isolation,reduced interior sound isolation, andmore acoustically-reflective surfaces onroom walls and ceilings (especially withskylights).More use of radiant/heating and cooling.Radiant heating and cooling is being usedmore for improved energy efficiency andimproved thermal comfort. As a resultthere is reduced HVAC noise; but, moreexposed metal and concrete mean morereflective surfaces. However, thermalmass which is used for energy savings canimprove sound isolation.Use of Sustainable Materials“Green” buildings use more sustainablyfarmed wood, metal (recycled andrecyclable), stone, and concrete thanconventional buildings. This means thereis a reduced use of acoustic ceiling tileand absorptive panels and a reduced useof carpeting. Note: acoustic tiles, panels,and carpeting all are being made in farmore sustainable ways so the trend awayfrom them might be changing.114 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

Advantages of “Green”BuildingsDesign teams of “green” buildings workin a more integrated fashion which meansbetter design team communication. Badacoustics from poor communicationamongst the design team is less likely,and more team members understand theperformance goals so acoustics goals areknown by all. Because there is more useof high-mass construction (concrete, filledCMU) in walls and floors there are bettersound isolation opportunities, and lessforced air HVAC means less HVAC noise.Occupants become aware of acousticsthrough education and post-occupancysurveysMajor NeedsThere is a need to get acoustics into thecriteria for green building rating systems,but this will be difficult because it doesnot have a direct monetary/sustainabilitymeasure. There is a need to educatearchitects and engineers on the importanceof including acoustics in the design, evenif the rating system does not—to makethem aware of the implications of pooracoustics (unhappy and unproductiveapplicants) and to make them understandthat some things cannot always be fixedafterward.Summary“Green” Buildings usually have worseacoustical performance than conventionalbecause rating systems do not incentivizegood acoustics. We need to change that.Green building designs also tend toremove sound absorbing materials andreduce isolating construction. However,“green” buildings also provide somegood opportunities for improved acousticperformance through coordinated,integrated design teams. The high-massconstruction provides opportunity forimproved sound isolation and createsa market for sustainable acousticalmaterials.Birgit Rasmussen – Noiselimits and building codesBuilding codes in Europe includeprovisions to control noise from severaltypes of sources, to address potentialadverse effects related to health, occupantcomfort, and avoidance of potentialconflicts. [1, 2, 3, 4, 5]• Sources of serious noise annoyanceidentified in recent surveys inEuropean countries include: local roadtraffic, neighbours, aircraft, industry,railways and motorways.• Effects of noise on health have beendocumented in many publications.• Acoustical comfort for occupants ofdwellings requires both an absence ofunwanted sound from elsewhere andthe opportunity for normal activitieswithout annoying other people.• To obtain acoustical comfort, criteriafor building performance must befulfilled for airborne and impact soundinsulation between dwellings, fornoise from external sources such astraffic, and for noise from technicalinstallations such as plumbing orHVAC systems.Regulatory requirements for controllingnoise from neighbours in multi-familyhousing vary widely between countries,using both different descriptors anddifferent numerical limits. [5, 6, 7]• A comparative study has beencarried out investigating regulatoryrequirements in 24 countries, plussupplemental sound classificationschemes in 9 countries.• Requirements for sound insulation usedescriptors defined in ISO 717 Parts 1and 2, and tests using ISO 140 parts 4, 5,and 7. Noise from technical installationsis tested following ISO 10052.• For airborne sound from neighbours,ISO 717-1 provides 15 descriptors,and for impact sound a choice of 6.National regulations have selected avariety of these.• Requirements for row housing differfrom those for multi-storey housing insome countries.• For airborne sound, approximateconversion to a single descriptor(weighted apparent sound reductionindex, R’ w) indicates that the requiredR’ wvaries from about 50 to 60 innational requirements (a range of 5 dBfor multi-storey and 10 dB for rowhousing).• For impact sound, approximateconversion to a single descriptor(weighted apparent normalized impactlevel, L’ n,w) indicates that the requiredL’ n,wvaries from about 42 to 63 innational requirements (a range of17 dB for multi-storey and 22 dB forrow housing).• Low frequency descriptors (importantfor lightweight construction) are usedonly in Sweden.• A European Action, COST TU0901,has been established to cooperate aboutharmonization.Regulatory requirements for controllingnoise intrusion through facades alsovary widely between countries, usingboth different descriptors and differentnumerical limits. [8]• Limits are defined in more ways:minimum façade sound insulationas a function of outdoor noise level,maximum indoor noise levels, ormaximum “night event” levelscombined with other criteria. All ofthese lead to sound insulation criteriafor the façade.• For façade insulation against noisefrom outside a variety of descriptorsare defined in ISO 717-1, which offers27 choices! (not counting 1/1 octavedescriptors and those with extensionsrelated to the type of source).• The descriptors applied for indoornoise level limits applied in somecountries are NOT defined in ISO 717.2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org115

Current trends are promoting changesfrom current regulatory criteria [5, 6]• There are more intrusive noise sources,including those due to neighbours’activities.• Demand for increased use oflightweight constructions will forcea shift to descriptors that include lowfrequency performance.• There is increased demand for higherquality, including acoustic comfort.• It is widely recognized thatmore flexible criteria are neededto supplement legal minimumrequirements – which could beaddressed by classification schemesthat offer a framework to design andmarket buildings that perform betterthan is required by regulations.Classification schemes for acousticalcomfort have been developed in nineEuropean countries [7, 8]• Most classification schemes aredeveloped as national standards.• The existing classification schemes alldeal with insulation from airborne andimpact sources in neighboring unitswithin a building, and most of theminclude noise from outdoors and fromequipment.• The nine schemes use several differentdescriptors. Some use descriptors thatinclude low frequency performance,others don’t.• The nine schemes have differentnumber of quality classes and classintervals.• Relationship to regulatoryrequirements varies, but most have twoclasses that are significantly better thanregulatory minimum.• With approximate conversion tocommon descriptors, the required R’ wfor the top category varies up to about65, and for the second category fromup to about 60. The criteria for impactsound show larger variation.• A European Action, COST TU0901,has been established to cooperate aboutharmonization.Summary:• Many descriptors are used for controlof airborne and impact sound fromneighbours.• There are large differences inregulatory requirements, especially forimpact sound.• There are also large differences amongnational classification schemes to labelbuildings with superior performance.• For lightweight buildings, lowfrequency sound is important, butrequirements for low frequencyperformance have not been adopted inmost countries.• Harmonization of descriptors andclasses are important to facilitateexchange of experience and reducebarriers to trade.References1. WHO Large analysis and review ofEuropean housing and health status(LARES) – preliminary overview,World Health Organization, RegionalOffice for Europe, Copenhagen;2007. http://www.euro.who.int/Document/HOH/lares_result.pdf2. Other relevant WHO links eg:http://www.euro.who.int/housing andhttp://www.euro.who.int/Noise3. WHO (2009) "Night noise guidelinesfor Europe". Regional Office forEurope, Copenhagen. ISBN 978 92890 4173 7. http://www.euro.who.int/Document/E92845.pdf4. ‘‘Research for a Quieter Europe in2020”. An updated strategy paperof the CALM network. EuropeanCommission. Research Directorate– General; 2007. http://www.calmnetwork.com/index_preports.htm5. "Sound insulation betweendwellings – Requirements in buildingregulations in Europe" by BirgitRasmussen. Applied Acoustics, 2010,in press. http://dx.doi.org/10.1016/j.apacoust.2009.08.0116. "Sound insulation betweendwellings – Descriptors in buildingregulations in Europe" by BirgitRasmussen & Jens Holger Rindel.Applied Acoustics, 2010, 71(3),171-180. http://dx.doi.org/10.1016/j.apacoust.2009.05.0027. COST Action TU0901 "Integratingand Harmonizing Sound InsulationAspects in Sustainable UrbanHousing Constructions", 2009-2013, http://w3.cost.esf.org/index.php?id=240&action_number=tu09018. Rasmussen B. Sound insulation ofresidential housing – building codesand classification schemes in Europe.In: Crocker Malcolm J, Editorin-Chief.Handbook of noise andvibration control, USA: Wiley andSon; 2007 [Ch. 114].Brandon Tinianov –Sustainable materials andnew developments forbuilding noise controlSpecifying green acoustical materialsis poorly understood and difficult toimplement from the acoustical expert’sperspective. One prime reason for this isthat the accepted definition of “green”is poorly understood by the acousticalcommunity[1]. The most widely acceptedinterpretation of the term does not referto building materials that have a highrecycled material content or is madewithout the use of toxic chemicals.While both of these elements can beimportant green building materialfeatures, the concept of green should andoften does, extend to the project whole.Taken together, the material and designimplications extend beyond materialcontent to water consumption, energyuse, and to the health and wellness of theoccupants. These larger considerationsare reflected in the most prevalent green116 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

ating system, the Leadership in Energyand Environmental Design (LEED) ratingsystem as established by the UnitedCouncil (USGBC).Within the framework of a larger, holisticbuilding system, an acoustical materialcan be considered green on three levels:a) its contribution to the health andcomfort of the building occupants; b)environmentally preferable nature of itscomponents or manufacturing process; c)its secondary performance features thathave a positive impact on other buildingsystems.An acoustical material’s contribution tothe occupants' comfort is second natureto a noise control expert. Appropriatematerials placed in the design candramatically increase the communicationand productivity of office workers andenhance the comfort of residents orpatients. These materials cannot bemanufactured and installed withoutnegative impact to the environment, butthat impact can be weighed against thebenefits of a building that is operatingmore efficiently.One example of such impact is a Detroitbasedinsurance company that designed itsnew office with improved privacy and newstate-of-the-art environmental systems.Evaluations showed a 137% decrease intime required to process client paperwork,a 9% drop in errors and defective claims,and a drop in absenteeism to 1.6 % from4.4 % [2]. As shown in a research studyacross a population of buildings, including400 manager interviews, respondentsestimated a 26% organizationalimprovement with the implementationof noise reduction strategies [3]. For thisreason, specifiers and consultantsshould work closely with the designteam to ensure that they understand thesebenefits as part of their higher profilegreen rating system rubric. The secondimportant factor of green acousticalmaterials is its material composition ormanufacturing process. In most greenrating systems, the constituent materialsof a product are considered green if itcontains recycled content (20 – 100%is preferred), uses rapidly renewablematerials, or uses certified wood products(See Table 1 below).The term ‘rapidly renewable’ refers toplant products that have much shorterplanting to harvest cycles than traditionallumber products. Specific materialexamples include bamboo, wheat, straw,and at times, young soft woods for usein chip board and oriented strand board(OSB) (see Figure 1). Credit for suchmaterials requires a certification fromthe manufacturer. Likewise, traditionalsoft and hardwood products can becertified as having been harvested bysustainable forestry methods. The woodsTable 1: Example of products with quantified recycles materials content (Source: A. Costello, Armstrong World Industries)2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org117

also bear a manufacturer’s certificationand chain of custody [4]. Consultants andpractitioners should avoid products withgeneral claims of greenness without usingspecific material features and supportingdocumentation (see Figure 2).The final facet of an acoustical material’sability to contribute to the greenobjectives of a building is its secondaryperformance features, beyond those ofacoustics. Such features may includethermal insulation allowing for a reducedHVAC load and downsized system; a lightreflective surface which increases thelevel of ambient daylighting in the space;increased fire suppression, or other. Onerarely considered green strategy is to useinnovative acoustical materials or designsthat require far less construction materials(e.g. stud walls with isolation clips ordamped panels that may replace heavymasonry or poured concrete construction).Information and guidance on suchsecondary benefits is scarce—acousticalexperts are advised to become involvedin the green design process and lookfor opportunities for their acousticaltreatments to benefit other systems. Asan immediate resource, some productmanufacturers are currently able tohighlight the secondary benefits of theirproducts. For example, Table 2 showsseveral examples of ceiling tiles thataccomplish both echo reduction via highNoise Reduction Coefficients (NRC)and high light reflectance (LR). A third,undocumented benefit may be that theproducts may contain recycled materialsin the product. Three, four, or five benefitsmay validly be attributed to a singleproduct or design strategy. If fact, manygreen rating systems encourage such anapproach.With regard to understanding the greenFigure 1: A manufacturer's example of recycled content andtraceability of their source materials (Source: Tectum Inc.)attributes of acoustical materials, theconclusion is complicated. Acousticalmaterials have a primary function ofacoustical comfort, which should be (andoften is) recognized as a basic tenet ofa green building. Materials should bespecified to that primary aim. However,acoustical experts can make informedmaterial decisions and participate withthe green design team to further enhancethe green objectives of the project. Theseadditional objectives can include usingmaterials with low environmental impactmaterials and those with secondarybuilding system benefits. These additionalobjectives can include using materials withlow environmental impact, and those withsecondary benefits to the building system.References1. While the words ‘green’ and‘sustainable’ do not have the sameprecise definitions, they are oftenused interchangeably—both inpopular and technical literature. Theyare used interchangeably here as wellto imply ‘environmentally preferableover traditional products or systems.’2. American Society of Interior Design,Sound Solutions: Increasing OfficeProductivity Through IntegratedAcoustic Planning And NoiseReduction Strategies, 2006.3. American Society of Interior Design,The Impact of Interior Design on theBottom Line, 2000.Figure 2: An example of poorly detailed or substantiated green claims (Source: internet search)118 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

Table 2: For multiple NRC ranges of interest, there is a high LR option (Source: A. Costello, Armstrong World Industries)4. At this time, the USGBC’s LEEDrating system only recognizes theForest Stewardship Council (FSC)as a valid third party wood certifyingagency.DiscussionLightweight BuildingConstructionQuestion: Please comment on Birgit’sstatement that the permission to constructlightweight buildings in Europe hascome more recently than it has inNorth America. Apparently it has comeselectively among different Europeancountries. When did lightweightconstruction come to Europe?Answer: One of the talks in the sessionon lightweight construction yesterdaysaid that it began nine years ago. Itmay have been earlier than that in somecountries. But there are still countrieswhere, for multi-family dwellings, it’sstill not allowed. In Austria, for example,it’s still being required that heavyconcrete and masonry construction formulti-family housing is used. But therecertainly is a very strong motivation tomove towards lighter-weight constructionand perhaps not as lightweight as woodframe construction or light steel frameconstruction. There are choices such assteel and concrete composites which inthat nebulous middle ground betweenthe heavy constructions where one canaccurately predict the performance of thesystem and the lightweight constructionswhere we are still gathering scientificinformation.Comment: Lightweight may be steel inload-bearing constructions, non-bearinggypsum stud walls, or wood in bearingor non-bearing constructions. In Swedenwood construction in high-rise buildingswas forbidden for many years untilrather recently. Now this is changed anddwelling houses with five or six floorsare allowed. They are built successfullyand with good sound insulation. This isa new development. Other lightweightconstructions with gypsum boards innon-bearing walls have been used for along time and have been allowed also forseparating walls between dwellings formany years.European ClassificationSystemsQuestion: What has been the drivingforce for the classification systems forsound insulation in Europe?Answer: My sense is that in many ofthe countries people are not aware thatthere is a market for better buildings.There are a lot of people who want betterbuildings and who want to have some wayof assessing what they are buying. In thesame way that energy efficiency ratingshave become common for many types ofhome appliances, a labeling scheme forbuildings tells people what they’re gettingso they can make a rational judgmentabout spending their money is verydesirable. The people who care about therating are prepared to spend for it.Comment: Sweden, with its socialwelfare system, developed economicsubsidies for housing quite some timeago. For many years, the subsidies fordwellings were the basis for the financingof new buildings. The rules did notpromote higher quality than the minimumrequirements demanded. There was nointerest in building houses with higheracoustical quality as this had no positiveeffect upon the economy. This financingsystem was changed 20 years ago. In 1993when a classification system for dwellingswas proposed, and this was welcomedby the building industry because thatcould create an economic incentive to2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org119

uild with higher quality. A classificationstandard was developed very rapidlywith three classes. Class C correspondsto the minimum requirements. Class B isapproximately 4 dB better, and Class Aanother 4 dB better. Builders soon foundout that customers in Stockholm wouldnot buy apartments that are not at leastClass B.Green Buildings in NorthAmericaQuestion: Please comment on thecorresponding attitude of the buildingindustry in North America.Answer: The building industry in NorthAmerica is not so dissimilar. They fighttooth and nail to stop changes in thelegislation and to keep the regulationrequirements as low as possible. But manyof them know how to build much betterand would welcome a system that wouldenable them to market more readily thebetter things that they build. It’s the sameway in which the energy efficiency ratingcame about, and it’s precisely the situationwith LEEDS where the LEEDS ratingsystem for green buildings has severaldifferent grades and has point systemsto provide more of an award for superiorperformance. A classification schemefor sound insulation in buildings is fullyconsistent with the requirements that thehigh end of the market has been lookingfor, but the acoustical community herein North America hasn’t provided thedesigners and buyers with the necessaryacoustical tools and standards.Comment: One of the impediments tohaving acoustics appear more often inthe green building rating system has beenthe lack of a consistent standard that thecommunity has agreed upon. We have astandard to measure, but we don’t have astandard to tell us what it should be. If oneconsiders ventilation, in North AmericaASHRAE 62 that has a listing of whatis required in terms of airflow. There’sa standard on how make measurements.There’s a standard of what the levelsshould be. With thermal comfort andASHRAE 55 gives the humidity range andtemperature range for a certain percentageof people to have thermal comfort. Thereis nothing on acoustics that links people’sannoyance or acceptability to a specificsound level whether it’s ASTC or OITC.That’s a missing link, and the people inthe U.S. Green Building Council say thatthey’d be happy to include acoustics ifwe could point to something to be givento the designers as a requirement. So it’son us.Comment: I agree completely.Daylighting is the same. But otherbuilding requirements have establishedsets of indices and readily usable toolsto calculate how the complete building isgoing to perform in terms of those variousindices. The ability to predict the soundinsulation of the complete system whichis needed for a meaningful prediction ofwhat occupants will hear is fundamentalto a green building system where they usemodels for the different disciplines forthe integrated design process. We haven’tprovided the tools; we haven’t provided acoherent consensus on rating schemes, sothey can’t include acoustics.Comment: We are working withpeople who are intelligently involved innoise problems. They know that thereare certain people who work on theseproblems and can find solutions, but whatpercentage of the population doesn’t knowthat there is knowhow around the world tohelp solve noise problems? We need someconcerted motivation on the big scalefor people who don’t know that noise isharmful and noise is disagreeable andnoise has bad attributes. Let them knowthere are solutions to noise problems.Until they make their demands known—which means paying for improvements—we’ll never get them. There are someidealistic people are working on the codes,but 50 percent of the public doesn’t knowabout codes, don’t know about noisecontrol. They may not know that noisecontrol is possible. We need concertedeffort by a respectable organization thathas reliability, motivation, and visibilityso people know that’s a organizationyou can depend on. We need that kind ofmotivation.Building CodesComment: In Birgit’s paper it showedthe variety and lack of consistency inbuilding codes in the 29 countries of theEuropean Union. She pointed out thatAustria has the toughest requirements, andother countries may be similar. They havetheir own requirements, and if a buildererects a substandard dwelling in Vienna,some authority will get after them and notallow them to build any more dwellingsor to sell them. This is motivation for thebuilding industry to keep up to at least a Cgrade or the lowest grade standard for thatparticular country. What have we in NorthAmerica except voluntarism? Volunteerscan spread the word that there are expertsaround; but if a fly-by-night builder is ableto sell a substandard dwelling it’s caveatemptor. Am I incorrect?Comment: I think you’re correct that thecurrent situation is such that under theletter of the law it’s not altogether clearwhether in Canada or the United Statesthe building code is enforceable in thesense of requiring a specific level of soundisolation. This is partly because it focuseson design requirements, not performancerequirements. So you must pick adesign that should, in principle, give theminimum performance. North Americanbuilding codes focus just on the ratingfor the separating assembly but don’tuse a rating like ASTC that applies tothe performance of the complete system.The building codes request builders topick part of the system that will be goodenough if the other parts are okay, but thebuilders don’t have to worry about theother parts.Comment: In Israel there are a varietyof courses which reflect the standards120 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

of different countries, different levelsof economy, and different varieties ofdevelopment in those countries. Themarket will do its job which means thosevarieties of standards goes from downup. It will generate a demand from thepublic, the people who seek standards,for better standards and a better life. Intheir effort to improve their standard ofliving, I believe that the people will win.There are two forces—the people and thegovernment—and in time the demand forimproved standards rise to those upperlimits.Comment: From time to time I talk to aknowledgeable consultant about HUD, theU.S. Department of Housing and UrbanDevelopment. I always thought therewere some minimum requirements in theUnited States under HUD regulations.The consultant says there are none; thereare no requirements for sound insulationin multi-family dwellings. Further, theguidelines HUD uses are good guidelinesas written by Ted Schultz in the 1970s, butthere have been no updates. A few yearsago I tried to find somebody in HUD whowould talk about acoustics, but nobodyin the entire department knew anythingabout the subject.Comment: I believe the consultant isboth correct and incorrect. The guidelinesthat were developed in the U.S. HUDdesign guidelines were enforceable atthe time there was the EPA noise officebecause they had the responsibility forbuildings that were constructed with U.S.government money which were publichousing facilities in some of our majorcities. That money dried up in the early70s, and there has been no more publichousing built with HUD funds. Buildingsconstructed by local or city governmentsdo not necessarily follow HUDguidelines. That’s why the consultantis right. Although you may be able tofile a civil lawsuit in the same way thatyou can with the American DisabilitiesAct—it’s a civil code. If you’re involvedin the construction of a public school,for example, nobody does inspectionsto check adherence to the guidelines.However, you can sue the entity and theyhave to make the changes if it’s found thebuilding was a poor design. That may stillbe the case with HUD regulations. If youlive in public-subsidized housing, you cansue and the building owners will have toaddress the problem. But it’s definitelynot in the building code. Building codesin the United States are driven 100percent by insurance and public safety.It started with the insurance companiesrefusing to insure a building that did nothave fire protection. When the buildingcodes were initiated there were groupsin American that worried about publicsafety. Consider the National ElectricCode with all its intricacies. Any changein that code has to be driven by safety.Will you show a reduction in the numberof lives lost, people injured, or buildingcosts in terms of fires that may be startedor safety of the building somehow. Thatis the driving force behind building codesas we have them throughout the U.S.Performance codes show up in guidelineslike the LEED and some cities havethem. Performance codes are always aseparate situation, and that’s where weare going to have to fit in, to get intoperformance-related codes because it’sgoing to be difficult to show the samelevel of detriment to the society withnoise problems disturbing people’s sleep.We know it’s a problem, and maybe it isa public safety issue but not the same asa fire burning down their house. Not thesame as not having enough ventilationso that people pass out, not the same ashaving a carbon monoxide buildup froma faulty installation. Noise is going tobe much harder to include in the U.S.building code. Is Europe different thatway?Comment: That’s my question also.The building codes in North America arestrictly designed. In other words, to get abuilding permit, you’ve got to submit thedesign of the building to the authorities.Once the builder gets the building permit,he can erect the building. There’s noperformance aspect of the building code;whereas in Europe, as I understand it,there are performance standards thatare established that are a part of thebuilding code so that a follow-throughon the design is carried out. In NorthAmerica it’s only the building inspectorswho get involved at the end of a project,and they’re not checking to the originaldesign. Am I correct?Comment: Yes and no. Many partsof the design are approved simply bylooking during the beginning phase.For the electrical installation, there areno performance requirements. You’rejust checking to see that the design isimplemented. However, things likeventilation rates are checked in biggercommercial buildings; but it dependson the situation of the building. Thechecking that is done is just to make surethe construction matched what the designwas but not checking the performance.Ventilation requirements are changing,and more cities have energy codes withstrict energy requirements that are beyondjust descriptive. Exterior rooms musthave fewer windows, and the energyperformance must be documented—somany BTU per hour or less.Design versus PerformanceQuestion: What about transmission lossbetween adjacent dwelling units?Answer: For transmission loss, in Canadaand the USA, the regulators do not checkthe performance.Comment: In Sweden real changeoccurred when we went from design toperformance. In the previous financingsystem, the responsibility for the designwas shared between the authorities andthe builder. Now the builder has the fullresponsibility. That made the change. Thesound classification system is based onmeasurements in the finished building. Itmust be proven through measurements2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org121

that the building fulfills a higher classthan C.Question: If the adjacent dwelling unitscannot fulfill the design specifications inSweden, are they allowed to rent, sell, orhave the building occupied?Answer: There are very few buildings inSweden that are not occupied. Our newlybuilt apartment houses have reasonablesound insulation quality.Comment: We are facing the phenomenaof “green” buildings now. The “green”buildings approach is to check the airconditioning system, the waste, the soil,the energy, and the acoustics. This is theresult of public pressure, from down up.The higher the standards, the greater theneed for improved acoustical design.Comment: The reference to the “green”building system is, I think, a perfectlyvalid one. Marketing “green” buildingsseems to be succeeding despite the factthat it is a design requirement almostentirely. Codes are moving now towardspost-occupancy evaluation, but in theearly stages it’s been purely in terms ofdesign and has caused a revolution indesign and in what’s being built. Howperfectly this is being achieved isn’tclear, but it’s drastically raised the scaleof what’s being built. Noise controlengineers should join that revolution.Transportation NoiseComment: I’d like to bring up the noisebarriers that are along the highways ofCanada and the U.S.A. A new interstatehighway was going into downtownBaltimore, but the Department ofTransportation said it would cost toomuch money. Much later demandincreased and now there are thousandsof miles of noise barriers along U.S. andCanada highways. Subsequent studiesshowed a lot more noise, dBs, and peoplenear highways than for airports. If it’splanned in the beginning, you can absorbthe cost and not even know it’s there.Comment: The comment about aircraftand highways is a good one. There hasbeen great progress in the aviation area,and there is more emphasis on aircraftnoise than there is on highway noise, butthe number of people affected by aircraftnoise is fairly small. So that’s a problem.The problems that affect a large numberof people are not getting addressed. Thosethat affect a small number of people havea lot of resources devoted to the problem.Question: Is the road traffic noiseproblem more serious in Europe?Answer: Yes, it is a problem for manymore people. In Europe aircraft areresponsible for 10 percent of the noiseannoyedpopulation, rail 5 percent, androad noise 85 percent. Most people areannoyed by road noise.Comment: The density of the populationis important. For example, Israel’spopulation is concentrated around TelAviv. Ben Gurion International Airportaffects over 1 million people.Comment: In Sweden in the early 90sthe National Action Plan Against Noisemade a limited study on the willingness topay for better sound insulation. We askedtwo questions: 1) Are you willing to payto be less annoyed by your neighbors? 2)Are you willing to pay not to annoy yourneighbors? The responses were almost thesame; there was an equal willingness topay by people annoying the neighbors asbeing annoyed by the neighbors. It wouldbe interesting to do the same study forroad transportation noise. To what extentwould drivers, car owners, be willing topay to not be annoyed and be willing topay to not annoy the neighborhood whendriving?SESSION 4: Codes,Practices, andStandards for LownoiseMachineryand EquipmentPanelists• Bob Hellweg, Consultant, U.S.A.,Session ChairOverview of standards and test codes• Jean Jacques, INRS, FranceInternational machinery and productnoise emission test standards andcodes• Matt Nobile, IBM, U.S.A.Product noise declarations for thegeneral public• Patrick Kurtz, BAUA, GermanyMachinery and product noise emissionlimits and requirements• Mike Lucas, Ingersoll-Rand, U.S.A.Limitations of current standards andtest codes• Hans Jonasson, SP, SwedenFuture needs for standards andtest codes for low-noise products,machinery, and equipmentPresentationsBob Hellweg - Overview ofstandards and test codes forproducts and machineryStandards and test codes can be brokeninto two categories: 1) Basic ISOstandards for product noise emissions:product sound power level - ISO 3740series; emission sound pressure level atthe operator position - ISO 11200 series;and noise declarations - ISO 7574 andISO 4871; and 2) machinery specific testcode standards: for example ISO 7779and ISO 9296 for information technology(IT) equipment and IEC 11600-11, -14 forwind turbines.The users of standards and test codes122 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

for products and machinery are themanufacturers who use them to test andreport to customers; to governmentson regulations, laws, and purchasespecifications; and for use on eco-labels(ECMA-370 IT Eco Declaration, BlueAngel). However, the purchasers ofproducts are the ultimate users of theresults of the standards. The developersand writers should realize this, in myopinion, important fact.The panelists in this session were giveneight questions (in italics) and backgroundfor the questions (See Page 83 forbackground.). Following some questionsare my responses.1. How can international test standardsbe more “user friendly”?2. How can we involve consumersand the public in the ISO and IECstandards development process?3. How do we ensure thatmanufacturers do not “cheat” on ormisrepresent the noise declarationsof their products?There is evidence that manufacturers havereported noise levels lower than those thatshould be obtained according to standards,resulting in unfair advantage over thosemanufacturers who follow the standards.Two examples of which I am personallyaware:The machine specific test code anddeclaration standard for IT equipment(ISO 7779 and ISO 9296) requiretesting of personal computers with fanspeed control at temperatures of 23˚C ± 2 ˚C for products with fan speedcontrol. Furthermore they also requiretesting of the emission sound pressurelevel L pAat the front operator position,which approximately 0.5 m in front ofa personal computer. I am aware of aEuropean PC company that measuresnotebook computer noise at 20 ˚C duringCPU operation and reports the emissionsound pressure level at bystander position(which is about twice the distancefrom the computer as the front operatorposition).Testing at an incorrect temperature resultsin fan speeds too low and A-weightedsound power levels and emission soundpressure levels are 2 to 5 dB (0.2 – 0.5 B)too low.Testing at a microphone position that istwice as far as the correct position resultsin an emission sound pressure level L pAthat is approximately 6 dB too low.Both result in the reporting of lowerthan required product sound data givingthe false impression that their productsare significantly quieter than theircompetition, which test properly. I haveevidence that another PC company is alsoreporting PC bystander position L pAinresponse to the first company claims.In addition to the two previous examples,there are also possibilities of unintentionalerrors in the reporting of noise valuesto customers.Many people andorganizations(with varyingdegrees ofexpertise) areinvolved inreporting noisevalues and theirimportance may be lost in the process:Developers of basic standard(expertise) => Developers ofmachinery test codes (less expertise?)=> Company engineer assigned toacoustics or external test lab engineer(less expertise) =>Test technician(still less expertise) =>Test reportwriter => Declaration determinationfrom test data and analysis =>Documentation writers => Sales andMarketing => end user.4. How can we ensure that teststandards enable or encouragethe application of technologywithout ambiguity and do not stifleinnovation by acting as barriers tothe implementation of technology?The International Standards mustprovide guidance for situations notconsidered by the standards.5. What new measurement standardsare needed? What currentmeasurement standards need majorrevision to improve their usability?6. How do we handle the confusion ofconsumers between sound powerlevel and sound pressure level andthe even more confusing use of thedecibel as the unit of measure forboth sound power level and soundpressure level?Why do acoustics standards use the same“metric” (decibels) for describing bothproduct sound power level and emissionand immission sound pressure level? Noother technical product attribute usesthe same unit to describe two differentquantities as illustrated in the followingtable:Energy Product Product Power Human ResponseThermal Heater Watts Temperature ˚CLight Light Bulb Watts Brightness, LumensAcoustic Washing Power – dB Pressure - dBMachineBased on the comparisons in the abovetable, consumers can easily understandthe difference in light bulb power andbrightness and in a heater power and thetemperature in a room; in my opinion itis not surprising that consumers do notunderstand the acoustics of products.The IT solution is to express the metricfor sound power levels in bels (instead ofdecibels) and keep the decibel to describeemission sound pressure level – thusconsumers are no longer confused onwhether the decibel value is sound powerlevel or sound pressure level.2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org123

7. In terms of product noisedeclarations (labels, tags, onlineinformation), actual numbersare important and useful forcharacterizing the noise emissionlevels, but how can we bestget “comparative” noise-levelinformation presented to a consumeron how one product compares toother products in the same family?8. With respect to product noisedeclarations what about productsthat are loud enough that anadditional concern (and perhapsthe only concern) is as a “NoiseHazard” with the potential forhearing damage?Jean Jacques – Internationalmachinery and product noiseemission test standardsand codes: Standardizednoise test codes for themeasurement and declarationof noise emission values ofmachinery and equipmentNoise test codes are machinery-specificstandards that specify all the informationnecessary for carrying out efficientlyand under standardized conditions thedetermination by measurement of noiseemission values of well identified familiesof machines. Based on ISO 12001 thatfixes the rules for drafting of noise testcodes, hundreds of noise test codes havebeen published during the recent yearscovering a large variety of machines andequipment. Some are ISO standards, manymore are European standards backing theEuropean regulation on machinery safety.These are essential tools for theimplementation of the internationalpolicy that consists, from noise emissiondata made available by machinerymanufacturers to potential clients andthrough market forces, to encourage theputting on the market and purchase oflow-noise machines.The next step is to enforce the useof these noise test codes by machinemanufacturers and the effective provisionby them of good quality noise emissiondata to their potential clients.Matt Nobile – Productdeclarations for the generalpublicHow do we get noise level informationto consumers so that they can makeinformed purchasing decisions? Ourbasic assumption is that we can increaseconsumer demand for quieter productsif we start providing them with easy-tounderstandnoise information in the sameway that we have increased consumerdemand for more nutritious food byusing nutrition labels, for more efficientappliances by using energy labels, and formore fuel-efficient cars by using mileagestickers.First let’s understand the terminology.There are three sub-classes of noisedeclarations: 1. Declarations publishedelectronically, 2. Declarations publishedin print, and 3. Declarations publishedas physical labels. For electronicdeclarations, which we hope will be theprimary approach, we have so-called“web declarations” that are marked updirectly in html, along with pdf filesand other online formats. For printdeclarations, which we hope will not bethe format of choice because they area headache to deal with, we are talkingabout noise declarations appearing in usermanuals, spec sheets, flyers, and otherhardcopy documents. And for physicallabels, we have labels affixed to products,removable tags on products, or physicallabels attached to the product or productpackaging. They are all “declarations,”and we prefer to use that term andreserve the word “label” for a physicallyapplied,stick-on label. However, theword “label” and the term “labeling” arevery entrenched already so we may findourselves using these terms even when thesubject is an electronic noise declarationon a company website.Although there are a few examplesaround the world of noise labels and noisedeclarations, most labels and declarationstoday are for energy. There are essentiallythree kinds of labels: 1. InformationLabels and Declarations, which provideinformation, and give actual values; 2.Comparative Labels and Declarations,which show a product in relation toother products of the same type, and 3.Endorsement Labels and Declarations,which put a seal of approval or stamp ofgood merit on the product.Last year we used the EU Energy Labelto illustrate the benefits of providingconsumers with product informationparticularly on a comparative basis —the EU Energy Label shows clearly howthe rated product compares with similarproducts on the market. This label hasbeen an overwhelming success in the 15years or so since its inception. Energyconsumption of appliances has decreasedbeyond expectations, so much so thatadditional categories like “A+” and“A++” have had to be added to the ratingsbecause so many products now exceedthe “best” performance envisioned whenthe labels were first introduced. We hopethat the same thing will happen withproduct noise. Finally, our proposal fromlast year was to institute a “Noise RatingTag” that looks a lot like the EU EnergyLabel, with its multi-colored bars, theA-G letter assignments, and the big, boldblack arrow, only in terms of noise levelsinstead of energy consumption.Although we thought it was a goodproposal, there were problems with usingthe EU label format. Foremost amongthem was that it was prohibited by EUregulations to use any kind of labelthat could be confused with the EnergyLabel. But that was fortuitous because itforced the INCE Technical Committeeon Product Noise Emissions to reevaluateour overall approach, and we found thatthere were other problems with using alabel based on the EU label format. Theseincluded: (1) Problems with using letters.124 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

Two products can have different lettersand be only slightly different in level(44.9 dB vs 45.1 dB); (2) Confusion aboutcell "edges" in general (not all "C's" arethe same); (3) Having both a declarednumber and letter can be confusing.Which is it, letter or number? (and whyhave both?); (4) Having a letter as partof a product rating prevents the range forthis type of product from being updatedin the future (e.g., EU label having toadd categories like A+ and A++); (5) The"block size" in terms of dB for each letterwould be different for different producttypes (i.e., the overall A-G range will bedifferent); (6) The "length" of the coloredlettered bars has no real meaning and addsconfusion; (7) "Quieter" is at the top, abit contrary to a "thermometer" type ofscale; and finally (8) No sense of wherethe particular A-G range of noise beingdisplayed fits into the overall range ofnoise levels.Therefore, we are introducing a brandnewproposal that we think is much betterthan last year’s proposal or anythingelse in the past. We note that engineersand the public want to know differentthings in terms of noise level information.While engineers may want to know thesound power level, sound pressure level,1/3-octave band levels, discrete toneratings, Sound Quality metrics, and othertechnical information, consumers reallywant to know just three things:1.How loud is this product?2. How loud is this product compared tosimilar products?3.Can this product damage my hearing?How loud is this washing machine?This is a question that we have not beenaddressing. Where in the overall rangeof noise levels does this product fall?And how loud is this washing machinecompared to other washing machines?The answer to this question will drivetheir purchasing decisions and lead toquieter products. And finally, can thisproduct damage my hearing? The publicwould like to have some sense from thenumber that is published whether or notthis is a hazardous noise level.Since it is nearly impossible to devise aproduct noise declaration with enoughdetail for engineers and practitioners yetsimple enough for the general public tounderstand, we are proposing that varioustrade associations (such as the InformationTechnology industry) simply continuewith their efforts to define and publishdetailed product noise declarations anddevelop standards governing their contentand use, but we define a new, simplified“Product Noise Rating” for the generalpublic. The goal of the new “PNR”scheme would be to answer the threequestions posed above.The new PNR scheme will definitelycontain a comparative element so thatconsumers can compare one product toanother, but this doesn't really answerthe fundamental question "How loudis it?" Even though I can learn that thisdesktop computer is quieter than anotheror that this hair dryer is the loudest on themarket, how loud exactly is it? Can I evenhear it? Will this annoy me? Do I needhearing protection?What is needed to answer these questionsin a way that the public can readilyunderstand is a simple "Noise Scale" thatshows the overall range of noise levels.This is the new and most importantelement of our proposal. The idea of ascale is not new as we are all familiarwith the Richter Scale. There’s a rangeof numbers on the scale, some simplelanguage description of what thesemean, and some examples. The publicunderstands roughly how powerful anearthquake is by these simple one-numberratings. There are many other types ofscales that have successfully presentedtechnical information to the public in aneasy-to-understand format.Our proposal is to establish a ProductNoise Rating (PNR) Scale for ratingthe noise levels of products for thepublic. It will be a numeric scale withsimple-language descriptions of what thenumbers mean and some examples. Allinterested parties and stakeholders willhelp us devise a consensus set of wordsand examples that define the scale, butthe point is that we will have a simplePNR scale that consumers can understand.What, then, are the units on the PNRscale? There are no units! (It's a ratingscale.) We feel that this will be mostimportant in getting the public to embracethe use of this new PNR scheme. As weall know, they have seldom been receptiveto the use of, or understanding of, thedecibel (or the bel).The use of a dimensionless scale is theprimary element of our new proposaland the main difference from previousproposals. The second element involveshow to present the PNR value toconsumers. We propose to use a “noiseometer”(like “speedometer”) icon. Ofcourse, other icon approaches may beproposed (such as a “thermometer”); itis the information that is important andit should be uniform. The noise-ometericon will display the overall range of PNRfrom 0 to 120. The big, bold arrow willclearly show where on the overall rangethe current product’s rating value falls.This answers the first question, “How loudis this product?”To answer the second question, “Howloud is this product compared to similarproducts?” we can superimpose a simplerange-of-levels segment along the overallscale that shows the range of PNRs forsimilar products. Again, this range oflevels information is what we feel willfinally drive down the noise levels ofproducts as consumers start routinelylooking for this comparative information.Finally, for the third question “Can thisproduct damage my hearing?” we proposeadding a "red zone" for potentiallyhazardous levels (again in analogy withthe red zone on a speedometer). Although2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org125

the overall discussion of whether or notsuch Product Noise Ratings should bevoluntary or mandatory is beyond thescope of this presentation, perhaps ifthe PNR is in the red zone, there mightbe a regulatory requirement to includean actual physical label or some kind ofwarning or safeguard on the product itself.In terms of logistics of implementing sucha Product Noise Rating scheme (scale plusicon), we anticipate that the following 5groups, at least, will be involved:1. INCE and the Technical Committeeon Product Noise Emissions, whichwill write a “Recommended Practice”for use of PNR .2. ANSI and ISO writing groups toturn that into a standard. Thereis a good precedent for this. TheINCE Technical Committee onInformation Technology Equipment,wrote a Recommended Practice formeasuring the noise emissions ofsmall air moving devices that wasfirst turned into an ANSI standardand later an ISO standard. This isnow the globally accepted way ofmeasuring the noise emissions fromsmall fans and blowers.3. A suitable “agency” – too early toidentify at this point – which willpublish guidelines or regulations foruse of the PNR based on the ANSI /ISO standard.4. Trade associations, which will playa key role and decide on the PNRrules for their products guided bythe agency guidelines and ANSI/ISO Standard. These groups will alsopublish detailed noise declarationsaccording to their own test codes andguidelines.5. Non-Governmental Organizations(NGOs) will play a key role inadvocating the use of PNR for allproducts, and publicizing quietproducts. The overall goal, of course,is to quiet the world and not just tostate the noise levels for the sake ofstating noise levels, so NGOs areexpected to play a key advocacy role.In conclusion, we believe that if aProduct Noise Rating for productsbecame as available as energy labels ornutrition labels, then the public will startpurchasing lower-noise products and evendemanding them. Furthermore, consumersmay be willing to justify spending alittle more when they see the “arrow”closer to the quiet end of the range ofsimilar products. When that happens, wemanufacturers will get the message and bemotivated to produce quieter products.Patrick Kurtz – Machinery andproduct noise emission limitsand requirementsNoise exposure at work places caused bymachines is still the major reason for themost important occupational disease inEurope. Although European Directivesexplicitly require to reduce the noiseemission of machines at source and toinform potential purchasers about theremaining risks by providing a noiseemission declaration, machines havenot significantly become quieter. Newideas are needed to foster the concept ofusing market forces in order to motivatemachine manufacturers to design quietermachines and to provide reliable noiseemission declarations. New approachesto better inform purchasers and tomotivate them to apply the noise emissiondeclarations are needed.RegulationsIn the EU the Machinery Directive (MD)was enacted in 1989 and updated withthe latest version effective 29 December2009. Its basic requirements are to reducenoise at source and provide a noiseemission declaration. The declarationmust include the A-weighted emissionsound pressure level (SPL) and thepeak C-weighted instantaneous soundpressure value at workstations and theA-weighted sound power level (PWL)emitted by the machinery. Besides theMD a second directive, “Outdoor”-Directive 2000/14/EC (OD), deals withthe noise of equipment for use outdoorsin the EU. The OD requires a label on theouter surface of the machine providing theguaranteed sound power level.Noise Emission Declaration FormatsTo allow a reliable declaration of noiseemission values required by the MD, theEuropean standard bodies were given amandate from the European Commissionto prepare noise test codes forming partsof so called C-standards (machinery safetystandards). They rely on B-standardswhich describe the basic methods todetermine both the A-weighted emissionsound pressure level and the sound powerlevel. Both quantities are characterizingthe machine as a source of airbornenoise and thus are independent from themeasurement environment.As the published noise emission valuesare used to allow the selection of quietmachines on the market, the operating,mounting, and installation conditionsmust be clearly defined. More than 750noise test codes have been published forspecific machines.Noise Emission Declarationsin PracticeAlthough there are many regulationsand agreements requiring or allowingthe information for potential purchasersabout the noise generation of products,reliable noise emission declarations arerare. The reason for this is simple. First,the given noise emission values are notunderstood by the laymen because thequantities used, both sound pressure andsound power levels, are given in dB(A)and thus interpreted as having the samevalue. Second, there are no referencevalues given describing the state of the artof noise reduction for the specific type ofmachine. An assessment of the quality ofthe provided data is almost impossible,and noise emission declarations accordingto the MD are in many cases unreliable.Typically they are lacking correct126 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

eferences to standards; the emissionvalues are measured for untypicaloperating conditions or use valuescopied from competitor´s declarations.Declarations may contain values whichlook nice to be particularly competitive,or are simply declaring emission valueswhich are just below exposure limitvalues, thus pretending to be on the safeside.On a very competitive market, 1 dB lowervalues may result in advantages whichmay motivate manufacturers to manipulatethe values. As the market surveillance hasso far ignored noise emission declarationsas an item to be checked, the onlysolution for the customer is to informthe manufacturer that before purchasethe declared noise emission values willbe part of the contractually guaranteedcharacteristics of the product. Experiencehas shown that such information can leadto a rapid increase of the declared noiseemission values before finally signing thecontract.Technical acoustical information seemsto be too complicated to be understoodby the purchaser of a machine orequipment and requires knowledgeof acoustics. As for the purchaser, theproduction performance, the price,service, maintenance etc. are the keyparameters defining the quality of aproduct; ergonomic or environmentalaspects are ignored. In consequence, thenoise emission of a machine or otherequipment is neglected. This has a strongeffect on the market because even thosemanufacturers producing quiet machineshave no additional benefit for their efforts.Thus reducing noise by choosing quietmachines has not been very successfuluntil now.New Ideas to Promote QuietMachinesTo promote the purchase of quietmachinery or equipment a proposalhas been made the European marketsurveillance advisory committee to checkthe present practice of noise emissiondeclarations according to the respectiverequirements of the MD. A steeringcommittee has been established. Theintention is to collect a large numberof noise emission declarations in thedifferent member states and to checkthe quality of these noise emissiondeclarations first by assessing theformat of the declaration and secondby a plausibility test concerning thedeclared values. A report will be writtendescribing the present state of noiseemission declarations in Europe andproposing ideas to improve the currentunsatisfactory situation. This could resultin better training for manufacturers asfar as the application of measurementand declaration standards are concerned.The idea of establishing a Europeanmachine data base containing noiseemission values could be revived with theconsequence that purchasers would geteasy access to comparable noise emissionvalues and also to information aboutthe state of the art of noise control for aspecific type of machine.In order to promote the use of emissionvalues, it is essential to explicitlydemonstrate to customers andoccupational health and safety people howeffective the purchase of quiet machinescan be to reduce the noise exposure ofworkers. This can be achieved throughmore industry-specific publications usingeasily-understood language and showingsimple examples for that industry. It willalso be necessary to develop applicableand easy-to-use software which allowsa rough estimate of the noise immissionat workplaces based on noise emissionvalues and room acoustic parameters fortypical workplace environments.However, there still remains the seriousproblem that dB(A) values are notunderstood as they do not always meanthe same thing. The difference betweenemission, immission, and exposurevalues is a significant barrier for nonacousticians.To understand the relatedquantities like emission sound pressurelevel, equivalent continuous soundpressure level at the work station, anddaily noise exposure level is difficult.Along with the sound power level, thisoften leads to complete misunderstandingsbetween manufacturers and purchasers/users of machines. The approach fromthe IT industry to use the B(A) insteadof the dB(A) for sound power level is nota solution. A more promising concept isthe energy label which uses an easy-tounderstandclassification system, whichpeople without technical backgroundsunderstand. However, that does not meanthe classical noise emission declarationsshould be replaced. No, the solution isa combination of both— a presentationof correct technical emission values andthe class system on one label. Althoughthis idea is simple, its realization iscomplicated. There are three importantquestions to be answered:• On what basis should the class limitsbe defined?• How can a representative amount ofnoise emission values be achieved inorder to define the class limits?• How should the dynamic process ofproduct development be handled toavoid outdated classifications?Although these questions are not easy toanswer, we should try to find answers.This idea has been adapted by manyother parties interested in the topic oflabeling. European gardening equipmentmanufacturers seem to be interested, andthe IT industry is likely to develop furthertheir approach to declaring noise emissionvalues. Presently the Federal Institute forOccupational Safety and Health (BAuA)in Dortmund is funding a project with theaim of establishing such a classificationsystem for office machines. Cooperationwith interested parties in the IT industry isin progress.ConclusionsThe application of noise emissionvalues to reduce the noise exposure at2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org127

workplaces is not yet very successful. Onemight call it a failure, although regulationson noise declarations and standards doexist. Moreover, employers are obligedto use these emission values whenbuying new machines in order to buycomparatively quiet ones. In consequence,it is time to take a new approach to besuccessful. Besides better informationfor all parties concerned, it may benecessary to develop a new format for thedeclaration of the classification systemsimilar to the European energy labelingfor house hold appliances.References2006/42/EC, Directive 2006/42/EC of theEuropean Parliament and of the Councilof 17 May 2006 on machinery, andamending Directive 95/16/EC (recast), OJL157/24, 9.6.20062000/14/EC, Directive 2000/14/EC of theEuropean Parliament and of the Councilof 8 May 2000 on the approximation ofthe laws of the Member States relating tothe noise emission in the environment byequipment for use outdoorsEN ISO 4871, Acoustics – Declarationand verification of noise emission valuesof machinery and equipment, 1996Nobile a. Matthew, “Noise Policy Forum,Motivating the Public to Demand Quiet”,Noise-Con 2008 DearbornMike Lucas – Limitations ofcurrent standards and testcodesTest codes are not perfect. Test codesare written for a wide audience of userswhere problems with the interpretationor implementation of the code are notrealized until the test code is fielded. It isno surprise that international standardscan be easily misinterpreted and abusedto gain a product market advantage. Thecreators of these standards need to bealways vigilant, they need to be alwayslistening to feedback from their users,and they need to be revising the standardsbased on input from the user community.Sometimes revisions to the standardsare not enough and laws are required toensure the true intended purpose of thestandard is achieved by the standardsorganization.In the past 10 years the InternationalStandard Organization has fielded alarge number of acoustical standardsthat have been adapted in some cases bywhole industries and in other cases byindividual manufacturers. Many times testcodes are referenced in the engineeringproduct literature. The declared valueand the referenced standard are used byconsumers when choosing between oneproduct manufacturer and another. Thisputs pressure on the manufacturer toachieve the lowest noise level possible togain market advantage. And here lies thecrux to the problem.In acoustics there are many techniquesfor measuring sound power of a product.Some of these techniques are more robustand less likely to give false readingsthan others. Depending on the size of theproduct or its installed running condition,some measurement techniques are not atall applicable to the given situation. All ofthese issues are taken into considerationby the creators of the measurementstandards. It is however unfortunate thatsome of these measurement techniquescan be abused to achieve a low productreading.It is the author’s opinion that acousticintensity is one of these measurementtechniques that can be abused and shouldbe avoided as a method for determiningthe declared value of a product. Intensityshould only be used when no othermethod can be reasonably applied. Thereare many situations where intensity cangive false readings, for example areaswhere large cooling vents expose theintensity probe to high velocities ofheated air. Other situations are areaswhere the machine can not be practicallyscanned because of its size or proximity toreflecting surfaces.How can international test standardsbe more “user friendly”? First, thestandards should be simple to useand can be easily understood by usersworldwide. The standard needs to beeasily understood by users that are notnecessarily trained in acoustics. Second,the instrumentation required by thestandard should be readily available andnot too expensive. Some manufacturershave small discretionary budgets limitingthe amount of resources they can allocateto noise testing. A type 2 sound levelmeter is the most affordable acousticinstrument that is available worldwide.Finally, the standard should take intoconsideration large machinery that has apackage cooling system. Often times thepackage cooling system is the greatestcontributor to the product noise and issometimes the most difficult to measureaccurately.How do we ensure that manufacturersdo not “cheat” on or misrepresent thenoise declarations of their products?On the whole, most manufacturers do notdeliberately cheat, but they may identifyweaknesses in the standard that can leadto lower measured noise levels. ISO-3744describes the measurement of sound powerusing a pressure microphone. ISO-3744is probably the most robust of the noisestandards and should be used wheneverpossible to measure a declared value ofa product. ISO9614-1 and 9614-2 aretwo acoustic intensity standards. Onestandard describes the measurement ofsound power by making measurements atdiscrete points and the other describes themeasurement of sound power using theacoustic intensity scanning technique. Bothof these techniques are accurate methods formeasuring sound power when performedby a trained expert in the use of acousticintensity, but without the proper trainingboth of these techniques can easily givefalse readings. Another problem with eithertechnique is the inability to make any kindof accurate measurement near a packagecooling system. As a result, many usersof acoustic intensity tend to scan aroundthe package cooling system, thereby not128 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

including in the measurement one of themajor contributors to the product noise level.How can we ensure that test standardsenable or encourage the applicationof technology without ambiguity anddo not stifle innovation by acting asbarriers to the implementation oftechnology? The ultimate goal is to lowerthe noise levels of consumer products. Toachieve this goal an environment needsto exist where all manufacturers are fairlycompeting among themselves. A simplyanalogy is a speed limit sign that hasno enforcement. Drivers will naturallyignore the sign until they learn otherwisethat there is a fine for not followingthe speed limit. Standardized productlabeling and enforcement will lead tonew innovation and technologies that willlower product noise levels. Standards canbe used to promote competition betweenmanufacturers when they know that theircompetitor is following the same systemof rules. If the standards are adaptedworldwide, then developing nationswill be encouraged to adapt the samestandards; thereby becoming a partner tothe world community in developing newtechnologies that will lower a product'snoise level.Hans Jonasson – Futureneeds for standards and testcodes for low-noise products,machinery, and equipmentThe paper focused on answering thefollowing three questions prepared by theorganizers:1. How can international test standardsbe more “user friendly”?2. How can we involve consumersand the public in the ISO and IECstandards development process?3. What new measurement standards areneeded? What current measurementstandards need major revision toimprove their usability?Examples on current problems behind Q1are:• The standards spend much space andeffort on problems that do not occurvery often;• Many equations, such as some newones on measurement uncertainty, lookterrifying, and tend to make peoplehostile to the standard;• The language is ”ISO English,” that isit is often not easily understandable.Some ways to improve the situation couldbe• Make simplified versions of the mostimportant standards. Another way todo this could be to exploit the fact thatto-day most standards are deliveredelectronically. This means that thetext could be held short and extrainformation, if needed, is given usinglinks to additional files.• Include preprogrammed spreadsheetswith the standard (See ISO 9612 forexample) where the only input ismeasured values and all calculationsare programmed. This is particularlyimportant for the new methods todetermine measurement uncertainty.• Create incentives to make standardssimpler (standards writers tendto be conservative and may needsome ”help” to carry out desirableimprovements).• Use more pictures and less text.Q2 is a difficult question but the followingactions could be a good starting point:• A first prerequisite is that the standardsare understandable by interestedparties, see Q1.• Make it cheaper (not so easy!) toparticipate in the standardizationprocess. In many countries you haveto pay for possibility to influencestandards.• Inform interested parties about currentprojects and provide the possibility togive feedback to the standardizers.• Distribute all ISO/DIS to interestedparties for additional comments to beconsidered by the WGs.Q3 on the need for new standards is toowide to be answered in detail but someexamples are the following:• For the basic sound power standardssystematic errors have to be dealtwith. Two such known errors are boxshapedmeasurement surfaces whendetermining sound power levels in anessentially free field above a reflectingplane and the erroneous assumptionthat the sound pressure level alwaysincreases by 3 dB when addingthe reflecting plane (Depending onmachine and frequency the increasemay be up to 6 dB)• Provide alternative measures for lownoise levels, the A-weighted soundpower level may not always be the bestsolution.• Improve methods to measure narrowband noise in semi reverberantenvironments in situ.• Sound power of multiple sources (cars,trucks, snowmobiles, etc.)• Allow for different impedancesurfaces, such as asphalt versusgrassland.• Prediction in the field from laboratorymeasurements where we need astandard describing in detail how wecan use measurement values fromthe laboratory to estimate the soundpressure level at the operator in a fieldinstallation.Finally, it was concluded that vastimprovements have been achieved ininternational standardization as a resultof the still ongoing globalization process.However, as focus has been on fillinggaps in current standards, not so muchhas been achieved in improving the userfriendliness of the standards. Althoughthere is still need for new standards itwould be beneficial for the future use ofthe standards if more effort was devoted tosimplify the practical use of the standards.2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org129

DiscussionComponent Sound LevelsQuestion: Should componentmanufacturers be forced to declare soundlevels to the public?Answer: For example, with componentmanufacturers we’re talking about fansthat are going into other products. I’mnot sure that an individual needs thisspecific information on the noise levelsof individual components that go into theend-use product.Comment: There are other problemswhich need to be solved, for instance,hydraulic pump descriptors. To describea hydraulic pump in the sense of a sourceacoustically is rather complicated. Weare only talking here about airbornenoise. But what about describing a fluidbornenoise source? I think we are stilllacking the right descriptors to do that.About 10-15 years ago we tried to haveWorking Group 22 define a descriptordescribing this structure-borne noisesource. We were unable to find a uniquedescriptor for the different ways in whichwaves are generated. As long as wehaven’t a solution for that, it’s simply notpossible to find an easy way to describea component and its contribution to theoverall sound of a machine.Question: When you have heavyequipment such as your companymakes, there is a big problem specifyinghow much noise it makes because itdepends highly not only on the operatingconditions but by how it’s installed. Howthe flexible connections are between yourequipment and other parts of the plantthat you have no control over. In otherwords, the installed noise can be radicallydifferent than was expected because of thepoor or excellent installation. How do youdeal with that?Answer: That’s an excellent question. Inparticular with centrifugal machines, mostof the noise occurs after the machine—atthe flange point—somewhere down thereyou’ve got a valve, and that valve you’vegot to close down so you can get thepressure you want to get. So all that noiseis going out of that valve. Well that’s notpart of the reported noise level of themachine. In addition, centrifugal machinescan be bigger than this room. So what doyou do? How do you measure it? And wedon’t have a good way to do that. AnotherU.S. company is using some techniquesthat I think are really solid. One of thoseis a standard that uses an accelerometer,and what you do is go around with anaccelerometer and measure the vibration,the structural radiation of that machine. Ihave been playing around with that quite abit and you’d be surprised at how accuratethat technique is because not only canyou identify the noise sources, but you’reisolating just the radiated sound from themachine and you’re not considering theseother sources. It’s kind of risky to use thatstandard because you can get differentnumbers if you’re not careful, but it’scertainly a good way to quantify the soundpower.Uncertainty Data for NoiseTest CodesQuestion: What is the interest of the usersof noise test codes to have well-defineduncertainty information included?Answer: The interest of the user dependson how to check the declared data. Ifthe measured value is reduced by theuncertainty, they are not interested in theprecise uncertainty. The users take theupper limit given by the basic documentsthat includes all possible families ofmachines. They are not interested inestablishing machinery-specific realisticvalues for their machinery. But if we donot allow subtraction of these values,then they are interested in more precisemeasurements.Comment: When we talk tomanufacturers, we are facing the situationthat many of them have no idea aboutuncertainty with their own products. Thetendency in this case is to simply referto the values made available in the basicstandards. I suspect those manufacturerswho have that information don’t want toshare such information.Involvement with StandardsDevelopmentQuestion: To involve stakeholders more,why can’t the objective and overviewof standards be supplied allowing forcomment including time taken formeasurements and example-simplifiedspreadsheets?Answer: As I said before, ISO is a veryconservative and difficult organization tochange. But if we start trying, I’m surethat sooner or later it will be possibleto make simplifications. This is a greatopportunity to start thinking about itbecause it’s quite clear that in the pastwe have focused on solving our technicalproblems and making the standards moreaccurate. Perhaps the focus could bechanged to make the standards more userfriendly.We have to find a solution to that.Existing procedures of ISO are extremelystrict, and one is not allowed to make anychanges. Thus changes may take sometime to achieve.Comment: The unfortunate situation isthat when we start to revise the standards,we have the feeling that no additionalexperience is gained. We are sitting withthe same people we have seen five or sixyears earlier.Comment: What is necessary is for themachinery-specific people to write anoise test code to clarify the advantageof having realistic lower values for theirmachinery instead of the limit valuesgiven by the basic standards.Comment: At the moment getting allpossible stakeholders involved is a majorissue for the whole standardization systemthroughout the world. It is not specific to130 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

acoustics; it’s a very general problem. Thesituation is not getting better; it’s gettingworse. Because we are now past the erawhen we had many experts around thetable—ISO staff to deal with problems,many manufacturers, and authorities.Now we get fewer and fewer expertsparticipating. There are financial problemsall over the world. The situation is notimproving; it’s more and more difficult toget the stakeholders involved. In Franceefforts are made to get consumers andtrade union representatives to participate,and there is some progress in thisdirection. Trade unions are importantbecause you will get feedback fromthe people who are actually using themachines everyday in their work. Thesepeople normally are not involved, so gettheir opinion about the problems theyhave met when using the machine.Comment: One of the major reasonsis that nowadays we depend more orless on the economic aspect. It must beshown that quiet machines will providea benefit for the company and willbring more income for the company. Ifwe don’t achieve this, we will have noimprovement at all. We have seriousproblems in getting representativesfrom machine manufacturers into theEuropean standardization groups. It’sunbelievable—you sit together withpeople who are in a position that doesnot allow them to discuss the technicalaspects. How can you then prepare agood standard? It’s almost impossible.Sometimes I run into a situation whereproposals are written based on ourknowledge but with the feeling that we’redeveloping the measurement methods fora type of machine about which we don’tknow enough.Question: Why is it so hard to getfeedback when revising standards?Answer: It is hard to get feedback frompeople who don’t want to talk to you.I keep suggesting that on the first pageof every standard a flashing light givingan e-mail address where the user of thestandard can react and submit ideas in hisexperience with the use of the standard.This is possibly a way for many peoplewho are using standards to understandthat standards are living documents thatare revised and they can contribute to therevision by letting the revisers know whatthey have done with the standard. Howthey like it; how they don’t like it.Question: How can we use the Internet toencourage the public to contribute towardsthe international standards?Answer: That sounds like a good idea.It is a bit problematic, but there aretraditional procedures of standardization.Hopefully it will be possible toget an agreement so we can makestandardization more transparent than itis today. Today there is a rather limitedway of developing standards. There maybe four or five people in the world whoseriously study the standards and arecapable of correcting them.Comment: The key questions for thisdiscussion are: What is the state ofthe technology? How do we make thestandards usable to help create a quieterenvironment?Comment: Those who really cancontribute to standards are probably herein this room. However, we also need tofind a number of individuals in five or sixdifferent countries who are willing to actpolitically to get something to happen.It is easier to find countries where thisis impossible, but what we are lookingfor is countries where we can get thepolicymakers high up in the hierarchywho can help us to drive the noise issuefurther internationally.Enforcing Product NoiseRequirementsQuestion: How do we require or enforceproduct noise requirements? Is it torequire or enforce per country or regiona viable, efficient approach? How do weglobally harmonize these?Answer: Let’s go back and look at whywas ISO successful. There were a numberof standards out there, and a numberof different standards organizations foreach of the different societies. Thosestandards were generating revenue forthe different societies. Then ISO camealong which is not really an internationalstandard but a European standardbecause every European country getsa vote—Luxembourg gets 1 vote, theUnited States gets 1 vote, China gets1 vote, and India gets 1 vote. So whatthat did was give ISO more leverage interms of how the standard was going tobe corrected and designed. In addition,many of the meetings were over in Europeso a lot of American manufacturers werenot able to go just because of travelcosts. But ISO did a very good job. Asa manufacturer worldwide my companywas forced to adhere to the rules, andwe scrapped our standards—there werea number of them—and went along withthe ISO standards. In addition, Americanstandards were worded so that they wouldbe recognized as ISO standards. That’swhy I feel that if we’re going to haveenforcement, ISO is going to have totake the lead again. America is not in aposition to take the lead given the politicalproblems that are going on and that there’snot going to be complete agreementamong all the companies. The Americancompanies will push back. Another thingis that we don’t have a densely populatednation like Europe does; and so noise iscertainly more important to the Europeansthan it is in America.Product Noise LabelingQuestion: Do you have enoughstakeholders involved with yourcommittee for their input in thedevelopment of your revised labelingproposal?Answer: Yes and no. The keyword there2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org131

is the development of the proposal. Wehave a pretty good cross-section on thetechnical committee itself—there areabout 35 involved INCE members. Toget final approval for whatever we aregoing forward with we need a muchbroader group of stakeholders. Gettingback to the word development, we haveenough representation on the technicalcommittee to produce a draft, andthat’s our immediate goal—to producea recommended practice, a draft thatwill then go to a much broader range ofrespondents and stakeholders to get thefinal version.There are stakeholders and there arestakeholders. The question was directedat my proposal and the key stakeholdersof my proposal, the public, want aproduct noise range for the public. Wehave ignored them in the past for variousreasons, and it’s not an identifiablegroup that we can approach. They donot attend our meetings, they’re noton the technical committees; but thatis changing. There are more and moreadvocacy groups out there such as theNoise Pollution Clearinghouse. It wouldbe a key stakeholder. Consumers Union inWestchester is another key representativeof the consumers. They’re not part of ourmeetings, but groups such as these are thestakeholders.Comment: I certainly encourage thisplan, but I have more of a cynical viewof this and that is that I feel ISO needsto take the lead because ISO is theone that started this. The reason is thatwhat happened with ISO, at least in thecompressor industry is that the standardcame down; we were forced to followbecause we sell products worldwide.Other countries around the world beganto adapt the standard, and that is whywe have a standard now today that weall follow. Prior to that we had a numberof different standards that we usedworldwide and, depending on the country,which standard we chose to use. So if ISOwere to develop a standard that wouldincorporate labeling and penalties, then Ithink that we have a good start.Question: If there are limits on products,who cares if there are informativenumbers for levels that are less than thelimit? Why regulate if there is no hazard?Answer: The situation mentioned withthe European directives in setting up limitvalues for very noisy machines is a goodidea. The problem was that too manylobbyists interacted, and it weakened thewhole preparation of the directive withthe consequence of the unstable situationwe now have. The consequence is thatnobody really deals with these numbersanymore. Even the state officials arenot dealing with them. A proposal wasmade for the European Commission tohave joint action on market surveillance.We agreed to have this action only forthe machinery directive, but only thatwe check the plausibility of the data.That means not measuring what hasbeen declared, but checking. This is aproblem for the stakeholders in marketsurveillance in Europe. So what happensif the declarations are wrong? Do wehave to give penalties for that? No, whatwe want to have is a good picture of thesituation. With this argument it is onlypossible to run this joint action on marketsurveillance. It’s really the state’s faultthat nobody controls it. It’s like hopingthe market will solve the problem, and themarket doesn’t solve the problem becausenobody is really interested. We must finda way to make consumers, customers,and factories aware of how to use thesevalues. Limit values should be used by allcompanies, maybe slightly changed, butthat’s something which is necessary. If wedon’t realize this broad use, we will neverfinalize what a good declaration is withreliable values or whether they are limitvalues or not.Answer: If it’s not hazardous, whyregulate it? There are two sides to this.The easy answer is, let’s not regulate it.If they do not pose a noise hazard, butare only quality-of-life effects, I’m forletting the market get the information tothe consumer. Having said that, I realizethere is another side to this. What I’veused in the past as an example on howgetting information out there can reallyhelp drive down noise levels, is the EUlabel on energy efficiency. It worked,and it’s continuing to work, and it islegislated. So it is mandatory to have thatlabel in Europe. Once that label is outthere, the efficiency increases. But I thinkthe jury is still out on whether or not it isbecause this is legislated or because theinformation was made available. I think itwas the latter. Once the information wasout there, the efficiencies went up. If wecan get the information out there withoutlegislation or regulation, I think the noiselevels will come down. But if we getto the point where consumers routinelysee this noise information available, areroutinely using it and manufacturers andtrade associations are still not publishingthe noise information, we can revisit thewhole issue of making it mandatory forlower-noise products.Comment: I would like to see quieterproducts manufactured and purchased.However, I don’t know if that is a goal oflabeling that we’ll have quieter productspurchased. I would like to think we let theconsumers have the option to purchasequieter products if they want to becauseconsumers don’t have that option today.If we do make available information onwhether the products are quiet, the marketwill drive it; and you will see quieterproducts as the result.Question: Product noise rating is theway forward. Let’s set up an internationalcollaboration to bring it through and putpressure on manufacturers worldwide tomake good quality noise emission dataavailable publicly. Is that feasible?Answer: The proposal which MattNobile presented today is a good stepin the right direction. In my institutionI’m responsible for customer help132 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

and guidelines, and this is one of thestrategic aims of the Federal Institute ofOccupational Safety and Health. We havea chance on special kinds of machines toestablish something which could be takenas an example for other product types.It is much easier to establish guidelinesin the IT industry than it is for concretebreakers. This may be a good exampleof how other manufacturers can beconvinced to have the same solution or atleast a comparable one.Comment: There are many Europeanproduct specific test codes which you canuse if you want to check products and thelabeling at the national level. In Europe,each nation is responsible for productcontrol and they can do what they want todo. The problem is that they don’t want tocarry out checking of noise levels becauseit costs money. Occasionally we havedone it in Sweden for, for instance, toyguns because the consumer agency hasbeen very active in this respect. Probablythey wouldn’t care so much about thesecompressors.Question: The need for labeling and theway to do it should strongly depend onthe number of products put on the marketin each category. There may be ten veryspecific machines of one type. There maybe 10,000 industrial compressors; theremay be 10 million laptops. How does onehandle that?Answer: There’s an implicit assumptionthat the need depends on the market size.I’m not sure I totally agree with that.We’ve been talking about a product as ifwe all know what a product is, but in ourtechnical committee there’s a task groupwhich is trying to define what we meanby a product that will bear the simplifiedproduct noise rating for the consumer.There are products where this informationis required, but for planners of datacenters, factories, or large compressors,we’re not anticipating the use of asimplified product noise rating for thiskind of equipment. There are differentneeds for the different products. We haveto differentiate the end purpose of theequipment in terms of the importanceof the “label.” For consumer productswhere we are talking about millions ofproducts, there is a need; and the needshould be for the simplified label thatI’ve been discussing. On the other hand,even if it’s a very small market of ten ora dozen large, noisy compressors that aregoing into a sensitive area, or there’s oneplanner who’s building one factory; theneed for accurate information on thoseproducts even for a small market is just asimportant.Cheating on NoiseDeclarationsQuestion: Where is the publishedevidence that manufacturers are“cheating” on noise declarations? Wewill put quotes around “cheating”meaning that they’re providing incorrectinformation on the noise declarations.Answer: There is no published evidence.At our U.S. company when we start anew line of products, we do a competitiveevaluation. We’ll buy a vendor’s machine,and sometimes we have to buy thesemachines under the radar so that theydon’t know what we’re buying. We setthese machines up and measure them. Wemeasure them for power, capacity; andwe measure them dimensionally. We havesurveys. We have people come in and theydo scorecard evaluations on these, andwe find the weaknesses and the strengths.One of the things that we measure isnoise, and that is where “cheating” comesup. I don’t know how to respond whenour marketing department says that themachine is 78 dB and they’re advertising74. Marketing asks me if we can make amachine at 74 dB, and I say yes, but it’sgoing to cost you and it’s going to add$1000 to the price of the machine. So it’sa struggle. That’s why I feel that it’s veryimportant to have honest numbers outthere.Comment: On a popular website itsays the measuring position for a PCis about one meter away from the PC;the standard says that you test at a halfa meter away. As acousticians we allknow that means a 6 dB lowering of thesound pressure levels. There’s evidenceof cheating there—presenting incorrectvalues. It is out there, but what can bedone? Those in this room who might workfor a manufacturer don’t do that, but weare aware of other companies who do.An analogy might be the Tour de France.We’d all like to think that the riders aredoing this on their own, but we very wellknow that many of the champions andtop riders have used a form of enhancingdrugs that shouldn’t be used. We’d like tothink they’re not doing that, but there aresome who do.Question: How are manufacturers ableto cheat using intensity in ways that theycan’t using pressure?Answer: As I pointed out, wheneveryou put an enclosure around somethingyou have two openings—an intake anda discharge. With acoustic intensity it’swell known if you get over 3 meters persecond, you can certainly influence thelevel and you can make it much higherthan what it’s supposed to be. WhatI suspect some people do is just scanaround the machine and ignore the venttotally. Just measure the radiation of thestructure. Because as soon as we go overthat hot air, your microphones are going toget very hot, they’re going to operate outof their specified ranges, and you’ve gotair blowing over them; and that’s a criticalproblem with intensity. That’s why whenwe had the ISO 2151 committee meetings,I sat in on those committee meetings. ASwedish company was there, and they liketo use intensity. I argued that we neededto include the hemispherical techniquewhich they finally did because the beautyof the hemispherical method is that youcan put your microphone four metersaway so that you’re far enough away fromthat air you don’t have any influence.NNI2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org133

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International RepresentativesBelow is a list of international contacts for the advertisers in this issue. The telephone number is followed by the fax number where available.In cases where there are two or more telephone numbers per location, or several locations within a country, a bullet (•) separates thetelephone number(s) from the respective fax number. Advertisers are asked to send updated information by E-mail to INCEUSA@aol.com.ACO PacificHong Kong/China: AP TechnologyLimited852 3114 6028 • 852 3114 6038Apmanli@biznetvigator.comHong Kong/China: Gelec(HK) Limited852-29198383 • 852 2591-0548alexwu00@hotmail.comKorea: ABC Trading Co.+82-2-2226-3161 • +82-2-2226-7383abctrd@abctrd.comBSWAAustralia: KINGfDOM PTY LTD+61 2 9975 3272kingdom@kingdom.com.auAustralia: Noise Measurement Services+61 7 3217 2850bob@noisemeasurement.com.auAustria: Ing. Wolfgang Fellner GmbH+43 1 282 53 43wf@shallmessung.comBelgium: ABC International Trading B.V.+31 162520447nl@abctradings.comCanada: Soft dB+1 418 686 0993contact@softdb.comEgypt: Elnady Engineering and Agencies+20 2 23425763info@elnadycompany.comFinland: APL Systems Ltd.+358(0)442199940Ville.ilves@apl.fiFrance: ViaXys+33 2 38 87 45 35oliver.blazere@viaxys.comGermany: ROGA Instruments+49 (0) 6721 98 44 54roga@roga-messtechnik.deIndia: Welan Technologies+91 20 25393126info@welantechnologies.comIreland: Sonitus Systems+353 01 2542560/+44 020 81236009enquiries@sonitussystens.comIsrael: Emproco Ltd.+972 (0) 8 6718187sales@emproco.comItaly: Spectra Sri+39 613321ecaglio@spectra.itKorea: SM Instruments Co., Ltd.+82 42 861 7004youngkey@smins.co.krSerbia: NORTH Point Ltd.+381 24 62 62 72gajins@north.rsSingapore: SHAMA Technoligies (S) Pte Ltd.+65 6776 4006shamatec@signet.com.sgSouth Africa: Vibranalysis Instruments S.A./+27 118867993 qqq +27 115075823laurence@vibranalysis.co.zaSouth America: SMART Tech+55 11 3168 3388marcelo@smarttech.com.brSpain: Anotec Consulting S.L.+34 916 897 540nico@anotec.comSpain: PROTOS Euroconsultores deIngeneria S.L.+34 91 747 5891Kimono.alexiou@protos-eci.esSpain: Uros Ingenieria+34 91 3329621Jalon_id@uros.esSweden: Acoutronic AB+46 87 650 280toby@acoutronic..seSweden: Arotate-Consulting AB+46 708 955150janos@arotate.comSweden: Sound View Instruments+46 (0) 70 681 79 89Anders.norborg@soundviewinstr.comTaiwan: OE SCIENTECH CO., LTD.+886 -2 25115747terry@oe.com.twTaiwan: Tops Technologies, Inc.+886 932 068 059kenlee@topstech.com.twThailand: Geonoise Instruments ThailandCo. Ltd.+66 042 342091info@geonoise-instruments.comThe Netherlands: ABC InternationalTrading B.V.+31 162520447nl@abctradings.comTurkey: DTA Ltd Sti.+90 224 280 84 44Akif.goksa@dta.com.trTurkey: VibraTek+90 0312 479 0302Ibrahim.Caglayan@vibratek.com.trUnited Kingdom: Sonitus Systems+353 01 2542560/+44 020 81236009enquiries@sonitussystens.comUSA: Scantek, Inc.+1 410 290 7726PeppinR@scantekinc.comScantek, Inc.Mexico and South America: CIAAMSADivisión Acústica(55) 1054 3209 • (55) 1054 3210nbenitez@ciaamsa-acustica.comSoundPLAN LLC2010 June www.inceusa.org • www.noisenewsinternational.net • www.i-ince.orgArgentina: Dakar ingenieria acusticaAArgentina: Dakar ingenieria acusticaArgentina+54 11 4865 79 84Soundplan@dakar-acustica.com.arAustralia: Marshall Day Acoustics+61 (0)2 9282 9422; +61 (0)2 9281 3611rleo@marshallday.com.auBrazil: GROM Acustica & Automacao+55 21 263 0792; +55 21 263 9108comercial@grom.com.brCanada: Navcon Engineering Network+1 714 441 3488; +1 714 441 3487Forschner@navcon.comChina: BSWA Technology Co., Ltd+86 10 5128 5118; ++86 10 8225 1626conghaidong@bswa.com.cnCzech Republic: SYMOS s.r.o.+420 220 999 977; +42 257225679symos@symos.czDennmark: SoundPLAN Nord ApS+45 39 46 12 00; +45 39 46 12 02jkl@soundplan.dkEgypt: Elnady Engineering and Agencies+2 (02) 23420896; +2 (02) 23426977info@elnadycompany.comFinland: Sound PLAN Nord+45 39 46 12 00; +45 39 46 12 02jkl@soundplan.dkFrance: Euphonia+33 02 40 18 05 18; +33 02 40 19 05 20contact@euphonia.frGermany: Braunstein + Berndt GmbH+49 7191 91 44 0; +49 7191 91 44 24bbgmbh@soundplan.deGreece: Acoustics Hellas+30 210 6630 333; +30 210 6630 334info@acoustics.grHungary: VIBROCOMP KFT+36 1 275 2138pbite@vibrocomp.huIndia: Foretek Marketing Pvt. Ltd.+91 80 2525 4706; +91 80 2526 6813info@foretekin.comIsrael: Labgoods Ltd.+972 3 6121341; +972 3 6121328email: ronen@labgoods.comItaly: Spectra s.r.l.+39 039 613321; +39 039 61 33235spectra@spectra.itIndoneisa: SHAMA Technologies (S) Pte Ltd+65 6776 4006; +65 6776 0592shama@singnet.com.sgJapan: ONO SOKKI Co. Ltd.Consulting Group, SV Development Center,Technical Headquarters+81 45 935 3818; +81 45 935 3806Watanan@onosokki.co.jpKorea (South): ABC TRADING+82 2 2226 3161; +82 2 2226 7383abctrd@abctrd.comKuwait: KuwaitGIS+965 2447733; +965 2456760info@KuwaitGis.comMalaysia: SHAMA Technologies (S) PteLtd+65 6776 4006; +65 6776 0592shama@singnet.com.sgMexico: Ing. Acustica Spectrum sa cv+55 57 52 85 13; +55 57 52 61 83acusticaspectrum@prodigy.net.mxNew Zealand: Marshall Day Acoustics+64 9 379 7822; +64 9 309 35 40siiri.wilkening@marshallday.co.nzNorway: SoundPLAN Nord ApS+45 39 46 12 00; +45 39 46 12 02jkl@soundplan.dkPoland: PC++ Software Studio+48 58 3075224; +48 58 3075224info@pcplusplus.com.plPortugal: AAC Centro de AcusticaAplicada SL+349 45 298233; +349 45 298261aac@aacacustica.comRomania: VIBROCOMP SRL Romania+40 723 614 524romania@vibrocomp.comRussia: Baltic State Technical University+7 812 7101573; +7 812 2988148marina_butorina@inbox.ruSerbia-Montenegro: Dirigent AcousticsD.O.O.+381 11 763 887; 381 11 763 887dgtdejan@yahoo.comSingapore: SHAMA Technologies (S)Pte Ltd+65 6776 4006; +65 6776 0592shama@singnet.com.sgSpain: AAC Centro de Acustica AplicadaSL+349 45 298233; +349 45 298261aac@aacacustica.comSweden: SP Technical Research Instituteof Sweden+46 10 516 5340; ++46 10 513 8381soundplan@sp.seTaiwan: Purtek Engerprise Co Ltd+886 2 2769 3863; +886 2 2756 7582purtek@ms13.hinet.netTurkey: Hid ro-Tek Ltd.Sti+90 2126598636; +90 2126598639aakdag@hidro-tek.com.trUnited Kingdom: Technical Development& Investigation+44 1787 478498; +44 1787 478328tdi.ltd@btconnect.comUSA: Navcon Engineering Network+1 714 441 3488; +1 714 441 3487Forschner@navcon.com137

AcknowledgementsINCE/USA Liaison ProgramACO Pacific, Inc..............................................................................Belmont, CaliforniaAVAC Continuing Education................................................Pittsburgh, PennsylvaniaColin Gordon and Associates...................................................San Bruno, CaliforniaAcoustical Solutions.......................................................................Richmond, VirginiaCavanaugh Tocci Associates.............................................Sudbury, MassachusettsG.R.A.S. Sound and Vibration....................................................... Vedbaek, DenmarkHarris Miller Miller & Hanson Inc..................................Burlington, MassachusettsNoise Control Engineering, Inc......................................... Billerica, MassachusettsOverly Door Company.......................................................Greensburg, PennsylvaniaScantek, Inc................................................................................... Columbia, MarylandVibro-Acoustics..........................................................Scarborough, Ontario, CanadaWyle Laboratories............................................................................Arlington, VirginiaSustaining Members of International INCEAcoustic Technologies (A-Tech).................................................... Brussels, BelgiumBrüel & Kjær.......................................................................................Nærum, DenmarkEcophon.............................................................................................. Hyllinge, SwedenG.R.A.S...............................................................................................Vedbaek, DenmarkLMS International, NV NumericalIntegration Technologies..............................................................Heverlee, BelgiumNarita International Airport Corporation (NAA).......................... Narita-City, JapanNorsonic AS.......................................................................................... Tranby, NorwayRion Company, Ltd..................................................................................... Tokyo, JapanInstitutional Members of International INCEArgentina................................ Centro de Investigacion en Acustica, Buenos AiresBelgium....................Laboratorium voor Akoestiek en Thermische Fysica, LeuvenConference CalendarBelow is a list of congresses and conferencessponsored by International INCE and INCE/USA. Alist of all known conferences related to noise canbe found by going to the International INCE page onthe Internet, www.i-ince.org.2011 July 25-27NOISE-CON 11Portland, OregonContact:Institute of Noise Control Engineering-USAAmy Herron, Conference CoordinatorINCE/USA Business Office9100 Purdue Road. Suite 200Indianapolis, IN 46268-3165Telephone: +1 317 735 4063E-mail: ibo@inceusa.orghttp://www.inceusa.org/nc112011 September 4-7INTER-NOISE 11Osaka, JapanContact: INCE/Japanc/o Kobayasi Institute of Physical Research3-20-41 Higashimotomachi, KokubunjiTokyo 185-0022Facsimile: +81 42 327 3847e-mail: office@ince-j.or.jphome page: http://www.internoise2011.com2012 August 12-15INTER-NOISE 12New York City, USAContact:Institute of Noise Control Engineering-USAAmy Herron, Conference CoordinatorINCE/USA Business Office9100 Purdue Road. Suite 200Indianapolis, IN 46268-3165Telephone: +1 317 735 4063E-mail: ibo@inceusa.orgFrance...................................Centre Technique des Industries Méchanique, SenlisKorea.......................................Center for Noise and Vibration Control Engineering,Korean Institute for Science and Technology,Science Town, Taejon-ChiNew Zealand.........................................................................Centre for Sound StudiesPortugal....................................... Laboratorio Nacional de Engenharia Civil, LisboaSweden............................. Department of Applied Acoustics, Chalmers Universityof Technology, GothenburgUSA............................................................................ Graduate Program in Acoustics,..............................................................................The Pennsylvania State University,..........................................................................................State College, Pennsylvania138 www.inceusa.org • www.noisenewsinternational.net • www.i-ince.org 2010 June

Directory of Noise Control ServicesInformation on listings in the Directory of Noise Control Services is available from the INCE/USA Business Office, 9100Purdue Road, Suite 200, Indianapolis, IN 46268-3165. Telephone: +1 317 735 4063: e-mail: ibo@inceusa.org. The price is USD400 for 4 insertions.NGC TESTING SERVICESAcoustical Testing LaboratoryASTM, ISO, SAE test capabilitiesincluding: E 90 (Floor-Ceiling &Partitions); E 492; C 423; E 1414; E1222(Pipe Lagging); SAE J1400(Automotive Barriers)Rental times also availablePlus Fire Test Services:E 84 (Flame Spread); E 119 (Endurance).1650 Military RoadBuffalo, NY 14217-1198716 873-9750716 873-9753 (Fax)email@ngctestingservices.comhttp://www.ngctestingservices.comSCANTEK, INC.Sound and Vibration Instrumentation& Engineering• Sales• Rentals• Calibration· NVLAP (NIST) Accredited• Service• Technical Support6450 Dobbin Rd. #AColumbia, MD 21045 USARichard J. PeppinTelephone: +1 410 290 7726Fax: +1 410 290 9167Web: www.scantekinc.comInfo@ScantekInc.comHESSLER ASSOCIATES, INC.Serving the Power Industry Since 1976• Ambient, Diagnostic andCertification Surveys• Environmental Assessments• Computer Modeling• Expert WitnessHessler Associates, Inc.3862 Clifton Manor Place, Suite BHaymarket, Virginia 20169 USAPhone 1: +1 703-753-2291Phone 2: +1 703-753-1602Fax: +1 703-753-1522e-mail: George@HesslerAssociates.comWeb: www.HesslerNoise.comThe Index of Advertisers contained inthis issue is compiled as a service to our readersand advertisers; the publisher is not liable forerrors or omissions although every effort ismade to ensure its accuracy. Be sure to letour advertisers know you found them throughNoise/News International magazine.ACO Pacific, Inc............................................. 75BSWA.............................................................. 73G.R.A.S........................................................... 136NGC Testing Servicces .................................75Price Noise Control Products ....................135Kinetics Noise Control................................ 134Odeom ............................................................136Scantek, Inc.................................................... 75SoundPLAN.................................................... 73Mark your calendar andplan to participate!NOISE-CON 2011Portland, OregonJuly 25 – 27, 2011The 27th annual conference of the Instituteof Noise Control Engineering, NOISE-CON2011, will run concurrently with the summermeeting of the Transportation ResearchBoard, Committee on Transportation-Related Noise and Vibration (ADC40)on Monday through Wednesday (25-27July, 2011). This conference is joiningthe overlapping transportation noise andvibration interest of the two organizationsin Portland, Oregon to take advantageof the strong public interest and readilyaccessible public transportation projectsites currently found in the PacificNorthwest. The technical program for thejoint conference will provide an opportunityfor public and private organizations toshare technical information on noise andvibration topics associated with high speedrail, light rail systems, highway surface andtire noise and aircraft noise to name a few.The INCE/USA Page at the Atlas BookstoreINTER-NOISE 06 ProceedingsThis searchable CD-ROM contains the 662 papers presented atINTER-NOISE 06, the 2006 Congress and Exposition on NoiseControl Engineering. This, the 35th in a series of internationalcongresses on noise control engineering was held held inHonolulu,Hawaii, USA on December 3-6, 2006. The theme ofthe congress was “Engineering a Quieter World.”www.atlasbooks.com/marktplc/00726.htmThe NOISE-CON 05 Proceedings Archive (1996-2005)This searchable CD-ROM contains 198 papers presented at thejoint NOISE-CON 05/ASA 150th meeting as well as 749 papersfrom the NOISE-CON conferences held in 1996, 1997, 1998,2000, 2001, 2003, and 2004 as well as the papers from theSound Quality Symposia held in 1998 and 2002. All papers arePDF files.The technical topics covered at INTER-NOISE 06 included:• Aircraft and Airport Noise Control• Community Noise• Fan noise and aeroacoustics• Highway, automobile and heavy vehicle noise• Machinery noise• Noise policy• Product noise emissions• Sound quality.Several papers are taken from sessions organized by theNoise, Architectural Acoustics and Structural AcousticsTechnical committees for this 150th ASA meeting. Thethree plenary lectures related to noise and its impact on theenvironment are included. Also included are papers in oneor more organized sessions in the areas of aircraft noise, tire/pavement noise, and hospital noise.

InTER-noISE ISE 09 CD-RoMThe Proceedings of INTER-NOISE 09, the 2009 InternationalCongress and Exposition on Noise Control Engineering arenow available on CD-ROM.This searchable CD-ROM contains 627 papers This, the 38thin a series of international congresses on noise controlengineering was held in Ottawa, Canada on August 23-26, 2009. The theme of the congress was “Innovations inPractical Noise Control.”The technical topics covered at INTER-NOISE 09 included:• Aircraft and Airport Noise Control• Active Noise and Vibration Control• Building Acoustics• Community Noise• Barriers• Fan noise and aeroacoustics• Highway, automobile and heavy vehicle noise• Machinery noise• Noise policy• Product noise emissions• Railway noise• Sound quality.These papers are a valuable resource of informationon noise control engineering that will be of interest toengineers in industry, acoustical consultants, researchers,government workers, and the academic community.Two indices of the papers presented atINTER-NOISE 09 are available on the Internet:Subject Indexhttp://www.atlasbooks.com/marktplc/00726internoise09index.pdfAuthor Indexhttp://www.atlasbooks.com/marktplc/00726internoise09author.pdfInTER-noISE 09 CD oRDER FoRMEnclosed is my check (or credit card authorization) for ________ U.S. dollars. Please send me ________ copies of the INTER-NOISE 2009CD-ROM at 80 U.S. dollars each. Shipping and handling charge: domestic, 3 U.S. dollars; all other countries, 6 U.S.dollars. Shipped by firstclass mail in the United States and by air mail to other countries. Stock number: IN09.Name Mr. Ms. Dr. Prof. _________________________________________________________________________________Address _________________________________________________________________________________________________________City ____________________________________________ State/Province _______________________ Zip/Postal Code _______________Country _________________________________________________________________________________________________________E-mail __________________________________________________________________________________________________________Credit card authorization:VisaMasterCardAmerican ExpressDiscover cardName on card (please print) _______________________________________________Card number:___________________________________________________________Expiration date (MM/YY): ________________________________________________Signature ______________________________________________________________You may order by postal mail, telephone (USA and Canada only), by FAX, or by e-mail. Postal mail: Bookmasters, Inc., Distribution ServicesDivision, 30 Amberwood Parkway, Ashland, OH 44805, USA. Telephone: 1 800 247 6553; FAX: 1 419 281 6883; e-mail: order@bookmaster.com.Internet: Go to the INCE/USA page at Bookmasters Atlas Bookstore. http://www.atlasbooks.com/marktplc/00726.htm

noISE-Con on 10 CD-RoMThis searchable CD-ROM contains PDF files of the 198 paperspresented at NOISE-CON 10, the 2010 National Conference onNoise Control Engineering. NOISE-CON 10 was held jointly withthe Acoustical Society of America on 19-21 April 2010 in theMarriot Waterfront Hotel in Baltimore, Maryland. This CD does notcontain the papers presented as ASA contributions.In NOISE-CON 10, there were 24 technical sessions:• Rocket Noise Environments• 15 papers Noise Control in Complex and Urban Environments• 11 papers Ventilation, Fan and Duct Noise Control• 21 papers Military Noise Environments• 16 papers Case History, Application and Integration ofArchitectural Acoustics in Building Modeling• 14 papers Materials for Noise Control• Manufacturer Presentations• 10 papers Building Design and Construction for EffectiveAcoustic Performance• 10 papers Experimental Techniques• 10 papers Construction Noise• 14 papers Information Technology Noise• 10 papers Aircraft Interior NoiseThis CD also contains Proceedings from NOISE-CON 08, NOISE-CON 07 and papers on sound quality presented as SQS08, the2008 Sound Quality Symposium. This CD-ROM supplementsthe NOISE-CON 05 CD-ROM which contains all of the paperspublished in NOISE-CON Proceedings from 1996 through 2005.These papers are a valuable resource of information on noisecontrol engineering that will be of interest to engineers in industry,acoustical consultants, researchers, government workers, and theacademic community.noISE-Con 10 CD oRDER FoRMEnclosed is my check (or credit card authorization) for ________ U.S. dollars. Please send me ________ copies of the NOISE-CON 2010CD-ROM at 70 U.S. dollars each. Shipping and handling charge: domestic, 2 U.S. dollars; all other countries, 5 U.S.dollars. Shipped by firstclass mail in the United States and by air mail to other countries. Stock number: NC10.Name Mr. Ms. Dr. Prof. _________________________________________________________________________________Address _________________________________________________________________________________________________________City ____________________________________________ State/Province _______________________ Zip/Postal Code _______________Country _________________________________________________________________________________________________________E-mail __________________________________________________________________________________________________________Credit card authorization:VisaMasterCardAmerican ExpressDiscover cardName on card (please print) _______________________________________________Card number:___________________________________________________________Expiration date (MM/YY): ________________________________________________Signature ______________________________________________________________You may order by postal mail, telephone (USA and Canada only), by FAX, or by e-mail. Postal mail: Bookmasters, Inc., Distribution ServicesDivision, 30 Amberwood Parkway, Ashland, OH 44805, USA. Telephone: 1 800 247 6553; FAX: 1 419 281 6883; e-mail: order@bookmaster.com.Internet: Go to the INCE/USA page at Bookmasters Atlas Bookstore. http://www.atlasbooks.com/marktplc/00726.htm