title: Using individual differences to test the role of temporal and place cues in coding frequency modulation.
abstract: The question of how frequency is coded in the peripheral auditory system remains unresolved. Previous research has suggested that slow rates of frequency modulation (FM) of a low carrier frequency may be coded via phase-locked temporal information in the auditory nerve, whereas FM at higher rates and/or high carrier frequencies may be coded via a rate-place (tonotopic) code. This hypothesis was tested in a cohort of 100 young normal-hearing listeners by comparing individual sensitivity to slow-rate (1-Hz) and fast-rate (20-Hz) FM at a carrier frequency of 500 Hz with independent measures of phase-locking (using dynamic interaural time difference, ITD, discrimination), level coding (using amplitude modulation, AM, detection), and frequency selectivity (using forward-masking patterns). All FM and AM thresholds were highly correlated with each other. However, no evidence was obtained for stronger correlations between measures thought to reflect phase-locking (e.g., slow-rate FM and ITD sensitivity), or between measures thought to reflect tonotopic coding (fast-rate FM and forward-masking patterns). The results suggest that either psychoacoustic performance in young normal-hearing listeners is not limited by peripheral coding, or that similar peripheral mechanisms limit both high- and low-rate FM coding.
authors.affiliation: Department of Psychology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Whiteford
authors.affiliation: Department of Psychology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Oxenham
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold; D003051:Cochlea / Q000502:physiology*; D003056:Cochlear Nerve / Q000502:physiology*; D003463:Cues; D004007:Dichotic Listening Tests; D004056:Differential Threshold / Q000502:physiology; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D008959:Models, Neurological; D010470:Perceptual Masking; D010507:Periodicity; D010897:Pitch Discrimination / Q000502:physiology; D025341:Principal Component Analysis; D011571:Psychoacoustics; D013997:Time Factors; D055815:Young Adult