title: The role of spectral cues in timbre discrimination by ferrets and humans.
abstract: Timbre distinguishes sounds of equal loudness, pitch, and duration; however, little is known about the neural mechanisms underlying timbre perception. Such understanding requires animal models such as the ferret in which neuronal and behavioral observation can be combined. The current study asked what spectral cues ferrets use to discriminate between synthetic vowels. Ferrets were trained to discriminate vowels differing in the position of the first (F1) and second formants (F2), inter-formant distance, and spectral centroid. In experiment 1, ferrets responded to probe trials containing novel vowels in which the spectral cues of trained vowels were mismatched. Regression models fitted to behavioral responses determined that F2 and spectral centroid were stronger predictors of ferrets' behavior than either F1 or inter-formant distance. Experiment 2 examined responses to single formant vowels and found that individual spectral peaks failed to account for multi-formant vowel perception. Experiment 3 measured responses to unvoiced vowels and showed that ferrets could generalize vowel identity across voicing conditions. Experiment 4 employed the same design as experiment 1 but with human participants. Their responses were also predicted by F2 and spectral centroid. Together these findings further support the ferret as a model for studying the neural processes underlying timbre perception.
authors.affiliation: Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, United Kingdom.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Town
authors.affiliation: Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, United Kingdom.
authors.forename: Huriye
authors.initials: H
authors.lastname: Atilgan
authors.affiliation: Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, United Kingdom.
authors.forename: Katherine C
authors.initials: KC
authors.lastname: Wood
authors.affiliation: Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, United Kingdom.
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Bizley
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000328:Adult; D000818:Animals; D001306:Auditory Pathways / Q000502:physiology; D001522:Behavior, Animal; D003463:Cues; D004192:Discrimination, Psychological; D005260:Female; D005289:Ferrets / Q000502:physiology / Q000523:psychology*; D006801:Humans; D008144:Loudness Perception; D008297:Male; D010897:Pitch Discrimination; D011571:Psychoacoustics; D013018:Sound Spectrography; D013045:Species Specificity; D055815:Young Adult