TY - JOUR
T1 - Loudness perception in the domestic cat
T2 - Reaction time estimates of equal loudness contours and recruitment effects
AU - May, Bradford J.
AU - Little, Nicole
AU - Saylor, Stephanie
N1 - Funding Information:
This research was funded by NIDCD grants R01 DC000109 and P30 DC05211. Eric Young and members of his laboratory contributed greatly to the conceptual design of recruitment experiments. In particular, the authors thank Michael Heinz and Diana Ma for their assistance with sound exposure. Roger Miller synthesized vowel stimuli. Denise Brown supervised animal husbandry.
PY - 2009/6
Y1 - 2009/6
N2 - The domestic cat is the primary physiological model of loudness coding and recruitment. At present, there are no published descriptions of loudness perception in this species. This study used a reaction time task to characterize loudness perception in six behaviorally trained cats. The psychophysical approach was based on the assumption that sounds of equal loudness elicit responses of equal latency. The resulting equal latency contours reproduced well-known features of human equal loudness contours. At the completion of normal baseline measures, the cats were exposed to intense sound to investigate the behavioral correlates of loudness recruitment, the abnormally rapid growth of loudness that is commonly associated with hearing loss. Observed recruitment effects were similar in magnitude to those that have been reported in hearing-impaired humans. Linear hearing aid amplification is known to improve speech intelligibility but also exacerbate recruitment in impaired listeners. The effects of speech spectra and amplification on recruitment were explored by measuring the growth of loudness for natural and amplified vowels before and after sound exposure. Vowels produced more recruitment than tones, and the effect was exacerbated by the selective amplification of formant structure. These findings support the adequacy of the domestic cat as a model system for future investigations of the auditory processes that underlie loudness perception, recruitment, and hearing aid design.
AB - The domestic cat is the primary physiological model of loudness coding and recruitment. At present, there are no published descriptions of loudness perception in this species. This study used a reaction time task to characterize loudness perception in six behaviorally trained cats. The psychophysical approach was based on the assumption that sounds of equal loudness elicit responses of equal latency. The resulting equal latency contours reproduced well-known features of human equal loudness contours. At the completion of normal baseline measures, the cats were exposed to intense sound to investigate the behavioral correlates of loudness recruitment, the abnormally rapid growth of loudness that is commonly associated with hearing loss. Observed recruitment effects were similar in magnitude to those that have been reported in hearing-impaired humans. Linear hearing aid amplification is known to improve speech intelligibility but also exacerbate recruitment in impaired listeners. The effects of speech spectra and amplification on recruitment were explored by measuring the growth of loudness for natural and amplified vowels before and after sound exposure. Vowels produced more recruitment than tones, and the effect was exacerbated by the selective amplification of formant structure. These findings support the adequacy of the domestic cat as a model system for future investigations of the auditory processes that underlie loudness perception, recruitment, and hearing aid design.
KW - Auditory reaction time
KW - Loudness estimation
KW - Sensorineural hearing loss
KW - Sound exposure
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U2 - 10.1007/s10162-009-0157-z
DO - 10.1007/s10162-009-0157-z
M3 - Article
C2 - 19198944
AN - SCOPUS:67349089030
VL - 10
SP - 295
EP - 308
JO - JARO - Journal of the Association for Research in Otolaryngology
JF - JARO - Journal of the Association for Research in Otolaryngology
SN - 1525-3961
IS - 2
ER -