Pitch perception is critical for recognizing speech, music and animal vocalizations, but its neurobiological basis remains unsettled, in part because of divergent results across species. We investigated whether species-specific differences exist in the cues used to perceive pitch and whether these can be accounted for by differences in the auditory periphery. Ferrets accurately generalized pitch discriminations to untrained stimuli whenever temporal envelope cues were robust in the probe sounds, but not when resolved harmonics were the main available cue. By contrast, human listeners exhibited the opposite pattern of results on an analogous task, consistent with previous studies. Simulated cochlear responses in the two species suggest that differences in the relative salience of the two pitch cues can be attributed to differences in cochlear filter bandwidths. The results support the view that cross-species variation in pitch perception reflects the constraints of estimating a sound’s fundamental frequency given species-specific cochlear tuning.
All psychophysical data and stimuli for this study have been uploaded to Dryad doi:10.5061/dryad.95j80kv).
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: The animal procedures were approved by the University of Oxford Committee on Animal Care and Ethical Review and were carried out under license from the UK Home Office, in accordance with the Animals (Scientific Procedures) Act 1986 and in line with the 3Rs. Project licence PPL 30/3181 and PIL l23DD2122.
Human subjects: Informed consent was obtained from human participants. Consent to publish was not required, as there is no identifying information present in the manuscript. All experimental procedures on humans were approved by the Committee on the Use of Humans as Experimental Subjects at MIT (Protocol 1208005210).
© 2019, Walker et al.
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