Westminster Open Spaces Noise Study 2008 Final Report

Westminster Open Spaces NoiseStudy 2008: Final Report4. Site visits and interviews with site users were carried out. Noise measurements weretaken at each site, simultaneously with interview sessions, to allow a correlation offindings between the two arms of the study.5. Classifications of sites were formed from site observations and a preliminary review ofinterview findings. Sites were then grouped into new typologies (see note on typologiesbelow)6. A toolkit was develop with weighted tranquillity factors for each typology7. Sites were assessed objectively by team members who had visited them, using theproformas provided with the Toolkit (see Toolkit below).2.3 Acoustic Measurement Methodology2.3.1 The majority of the sites were visited for a period of approximately one hour during aweekday in the period 13 October 2008 to 12 November 2008. The two sites visited at theweekend were on the edge of Hyde Park near the café and the Rose Garden on Saturday1 November 2008 a ; it was considered these would be more populated during the weekendsand hence have a different noise climate than during the week. During all the visits, noisemeasurements were made simultaneously to the social surveys.2.3.2 The noise instruments were set up at a point considered typical of the site as a whole.Where possible this was chosen to be central to the open space. Care was taken not tocause an obstruction to the users of the site or to be too close to an obvious local noisesource, such as building service equipment in nearby buildings. Multiple measurementswere taken at larger sites such as Hyde Park, Regent’s Park and St James’s Park to reflectthe different soundscapes at the edge and centre of each site.2.3.3 Noise measurements were undertaken with a 5-minute logging period, and recorded noiseindicators included: L Aeq , L AF10 , L AF90 , L AFmax and 1/3-octave L eq sound pressure levels foreach 5-minute period b .2.3.4 In addition to the noise measurements and social surveys, a site pro-forma was completedat each site to capture the following information:• Instrumentation used for noise measurements, including calibration records;• Weather conditions during measurements;• Audible noise sources noted during the site survey (categorised, with spaces foradditional noise sources and comments);• A subjective assessment of noise climate at the site (the opinion of acousticconsultant undertaking noise measurement, and separate from the questionnaireresponses).2.4 Acoustic Measurement Data Processing2.4.1 Analysis of the acoustic measurement data has included comparison with a number ofreference noise levels and noise guidelines, including the following:a It was envisaged that a greater proportion of sites would be visited during the weekend, however this was not possibledue to inclement weather and timescale constraints.b A glossary of noise terminology is included in Appendix A to this report.D121316/R1/024Scott Wilson LtdMarch 2009