FRIDAY MORNING, 20 MAY 2005 REGENCY E, 8:30 A.M. TO 12:00 ...

More documents

Recommendations

Info

FRIDAY MORNING, 20 MAY 2005 PLAZA C, 8:50 TO 11:30 A.M. Session 5aAB Animal Bioacoustics and ASA Committee on Standards: Behavioral Audiometric Methods in Animal Bioacoustics: The Search for Standards I Edward J. Walsh, Cochair Boys Town National Research Hospital, Omaha, NB 68131 Ann. E. Bowles, Cochair Hubbs-Sea World Research Inst., 2595 Ingraham St., San Diego, CA 92109 Chair’s Introduction—8:50 Invited Papers 9:00 5aAB1. Common hearing functions among mammals and birds. Richard R. Fay Parmly Hearing Inst., Loyola Univ. Chicago, 6525 N. Sheridan Rd., Chicago, IL 60626, rfay@luc.edu Among many mammals and birds, frequency-place cochlear maps have a similar form and differ primarily with respect to the length of the cochlea or basilar papilla, and with respect to the frequency range of hearing. This is remarkable, especially given the differences in anatomical organization and evolutionary history between mammals and birds. This is a striking example of convergent or parallel evolution. With few exceptions, the cochleae of mammals and birds are indeed scale models of one another. One of the primary functions of the frequency-place map is in frequency analysis. Whether this function is defined by frequency discrimination thresholds, critical masking ratios, critical bands or auditory filters in general, frequency analytic performance, behaviorally-defined, can be laid out on the basilar membrane and a critical basilar membrane distance can be associated with a given performance criterion. In general, these critical distances differ according to the function e.g., frequency delta Fs versus critical bandwidths, but are remarkably similar functions of frequency within and between species they tend to be constant. It seems likely that evolution has selected the consequences of frequency analytic mechanisms for perception rather than the mechanisms themselves. Work supported by NIH. 9:20 5aAB2. How do you know what an animal can hear? Henry E. Heffner Dept. of Psych., Univ. of Toledo, Toledo, OH 43606 The comparative study of hearing is based on the ability to obtain valid behavioral measures of hearing in different species. This requires careful generation and measurement of sound, a behavioral task and reinforcer appropriate for the species, and a comparable definition of threshold. For audiograms, it is important to generate artifact-free pure tones and test with the animal’s head fixed in a free-field sound field. For sound localization, a two-point discrimination with the animals head fixed in the sound field is commonly used. For all discriminations, it is important to obtain data for stimuli that are below threshold to ensure that an animal is not using extraneous cues. Descriptions of techniques should be sufficiently detailed to allow other researchers to replicate them; new techniques can be calibrated by replicating the results of others. Behavioral procedures that work well with one species may not elicit optimal performance from others. Although performance should be corrected for false positives, signal detection measures are difficult to interpret and cannot compensate for the failure to keep an animal under stimulus control. In general, valid results are obtained by following good scientific practice. 9:40 5aAB3. The critical band and the critical ratio. William A. Yost and William Shofner Parmly Hearing Inst., Loyola Univ. Chicago, 6525 N. Sheridan Rd., Chicago, IL 60626 The critical band is arguably one of the most important psychophysical descriptors of auditory function. The critical ratio is often used in animal psychophysical research to estimate critical bandwidth because it is easier to obtain than estimates of critical bandwidth. However, in most cases the underlying assumptions required to use the critical ratio as an estimate of critical bandwidth are rarely met. The critical bandwidths for chinchilla and guinea pigs are similar to those obtained for human subjects, while the critical ratios are considerably higher, an observation that violates the use of the critical ratio as an estimate of critical bandwidth. This paper will describe the assumptions necessary for the critical ratio to estimate critical bandwidth. We will describe data on critical bands and critical ratios for chinchilla and guinea pigs, and we will provide evidence that the chinchilla appears to be a wideband processor of the signal in critical-ratio experiments. The inability of the chinchilla to process the signal in its narrow critical band in the criticalratio psychophysical procedure leads to the large critical ratios. We recommend that the critical ratio not be used to estimate critical bandwidth. Work supported by NIDCD grants to Dr. Yost and to Dr. Shofner. 2582 J. Acoust. Soc. Am., Vol. 117, No. 4, Pt. 2, April 2005 149th Meeting: Acoustical Society of America 2582
10:00–10:10 Break 10:10 5aAB4. Estimating loudness in animals. Micheal L. Dent Dept. of Psych., 361 Park Hall, Univ. at Buffalo-SUNY, Buffalo, NY 14260, mdent@buffalo.edu Although auditory acuity experiments in animals are valuable, this is not how animals typically encounter real world sounds. It is also important to know how animals respond to stimuli at more ‘‘realistic’’ intensities. The perception of above-threshold level sounds has been well documented in humans, but is much less studied in animals, where acoustic communication is important for survival. In humans, equal loudness contours are used to show that loudness does not increase with intensity equally at all frequencies. Loudness is a subjective experience, however, and much harder to measure in animals. Reaction time is one untrained response that can be used to gauge how different or similar two stimuli are: high intensities yield short and low intensities yield long reaction times. Comparing reaction times across frequencies equal latency contours in birds and mammals show results that are similar to equal loudness contours obtained in humans. At low SPLs equal-latency contours closely parallel threshold curves, while at high SPLs the contours flatten and all frequencies are perceived as being about the same loudness. These results in animals should be considered when thinking about aspects of acoustic communication such as sound transmission, vocal signals designs, and sound-attenuating properties of the environment. 10:30 5aAB5. Animal behavioral psychoacoustics: Issues related to methodology and interpretation. David Kastak, Ronald Schusterman, Brandon Southall, Marla Holt UCSC Long Marine Lab., Santa Cruz, CA 95060, and Colleen Kastak UCSC Long Marine Lab., Santa Cruz, CA 95060 A brief survey of the literature in animal behavioral psychophysics shows that researchers use numerous methods to obtain information on sound detection, discrimination, and identification. Behavioral methodology in animal psychoacoustics includes both classical and operant conditioning, go/no-go or multiple alternative forced-choice tasks, and various methods of estimating detection and discrimination thresholds. Recent emphasis on comparing data across subjects, species, and media e.g., hearing in air versus water, as well as investigations into the effects of age, noise, and ototoxins on auditory perception highlight the need for methodological standardization. In this paper we will discuss several important issues related to behavioral audiometrics, focusing primarily on marine mammals. These issues include variability among species, individual subjects, and laboratories; experimental concerns such as time constraints; adaptive versus non-adaptive psychophysical methodology and threshold reliability; signal detection theory versus threshold models of audition and the search for unbiased estimates of auditory performance; and measurement and interpretation of subject response bias. Standards for animal psychoacoustic methodology should be sensitive to each of these factors. 10:50 5aAB6. Body size and assessment of auditory function: A comparative conundrum. Edward J. Walsh, JoAnn McGee Boys Town Natl. Res. Hospital, Omaha, NE 68131, John Rosowski, and William Peake Harvard Med. School, Boston, MA 02115 One goal of the bioacoustics community is to compare auditory function among species representing the entire animal kingdom, including terrestrial mammals. As an alternative to behavioral measures, it is frequently necessary, and/or desirable, to assess auditory function using electrophysiological approaches. Body size is an important factor that can effect the distribution and amplitude of evoked brain potentials EP measured from the surface of the head and the ranges of body mass and size within Mammalia are extensive. Consequently, the development of comparison protocols must include consideration of factors affected by size differences, e.g., the distance between EP generators and recording electrodes and the thickness of the skull. Ultimately, these factors, along with the acoustical character of the recording environment itself, affect acquired signal-to-noise ratios SNR. In this context it is notable that the SNR associated with large animals are reduced relative to those observed in smaller animals, making the comparison of results from one species to another complex. This procedural challenge is further complicated by the requirement to acquire data efficiently and rapidly in recording environments that are non-optimal from an acoustic perspective. These issues will be addressed by considering auditory brainstem responses in tigers, bobcats, manuls, sandcats and rodents. 11:10 5aAB7. Psychometric data and standards for the estimation of noise exposure for animals. Ann E. Bowles Hubbs-SeaWorld Res. Inst., 2595 Ingraham St., San Diego, CA 92109, annb1@san.rr.com ASA standards are used in the estimation of noise exposure for humans. The approaches pioneered for humans can be used as a model for animal standards, but a number of differences must be considered. First, animal standards will normally be applied across multiple taxa rather than to a single, monotypic species. Thus, it will be essential to find defensible methods for generalizing across taxa. Second, samples of subjects and measurement conditions are often inadequate in animal studies e.g., measurements on a single animal, noisy testing conditions, but may be the only data available. Therefore, standards are needed for specifying the limitations of various data sources. Third, taxa may have very different psychoacoustic capabilities e.g., best sensitivity, temporal integration time, and loudness perception. Therefore, comparative measures will be essential. For example, while weighting functions for humans are standardized to zero at 1 kHz, there are advantages to developing weighting functions for animals with an appropriate correction for taxon-specific sensitivity. Although the differences between standards for animals and humans represent a significant challenge, the development process and research in support of animal standards will yield valuable new perspectives that could be applied to humans in the future. 5a FRI. AM 2583 J. Acoust. Soc. Am., Vol. 117, No. 4, Pt. 2, April 2005 149th Meeting: Acoustical Society of America 2583
Page 1 and 2: FRIDAY MORNING, 20 MAY 2005 REGENCY
Page 3: given the simple geometry, and serv
Page 7 and 8: 9:00 5aBBa5. Image-guided high inte
Page 9 and 10: 9:20 5aBBb4. Shear wave interferome
Page 11 and 12: FRIDAY MORNING, 20 MAY 2005 BALMORA
Page 13 and 14: Contributed Paper 11:45 5aMU9. The
Page 15 and 16: 11:15 5aNS8. Digital identification
Page 17 and 18: FRIDAY MORNING, 20 MAY 2005 REGENCY
Page 19 and 20: 5aPP3. Comparing linear regression
Page 21 and 22: plained from Outer-Hair-Cell OHC ac
Page 23 and 24: 5aPP24. Utilizing different channel
Page 25 and 26: 11:30 5aSA10. Vibration control of
Page 27 and 28: for statistical characterization of
Page 29 and 30: nificant impact on the intelligibil
Page 31 and 32: FRIDAY MORNING, 20 MAY 2005 GEORGIA
Page 33 and 34: FRIDAY MORNING, 20 MAY 2005 GEORGIA
Page 35 and 36: separability or quasi-separability
Page 37 and 38: 2:30 5pBB2. A system to evaluate an
Page 39 and 40: 2:10-2:15 Break 2:15-4:15 Panel Dis
Page 41 and 42: cess by which speakers alter their
Page 43 and 44: very limited and mostly based on di
Page 45 and 46: hearing were presented with voices
Page 47: esults, the feasibility of performi

FRIDAY MORNING, 20 MAY 2005 REGENCY E, 8:30 A.M. TO 12:00 ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?