Effects of temporal stimulus properties on the perception of across-frequency asynchrony.
The role of temporal stimulus parameters in the perception of across-frequency synchrony and asynchrony was investigated using pairs of 500-ms tones consisting of a 250-Hz tone and a tone with a higher frequency of 1, 2, 4, or 6 kHz. Subjective judgments suggested veridical perception of across-frequency synchrony but with greater sensitivity to changes in asynchrony for pairs in which the lower-frequency tone was leading than for pairs in which it was lagging. Consistent with the subjective judgments, thresholds for the detection of asynchrony measured in a three-alternative forced-choice task were lower when the signal interval contained a pair with the low-frequency tone leading than a pair with a high-frequency tone leading. A similar asymmetry was observed for asynchrony discrimination when the standard asynchrony was relatively small (≤20 ms) but not for larger standard asynchronies. Independent manipulation of onset and offset ramp durations indicated a dominant role of onsets in the perception of across-frequency asynchrony. A physiologically inspired model, involving broadly tuned monaural coincidence detectors that receive inputs from frequency-selective onset detectors, was able to accurately reproduce the asymmetric distributions of synchrony judgments. The model provides testable predictions for future physiological investigations of responses to broadband stimuli with across-frequency delays.
Department of Psychology, University of Minnesota, 75 East River Road, Minneapolis, Minnesota 55455, USA. wojtc001@umn.edu
Magdalena
M
Wojtczak
Jordan A
JA
Beim
Christophe
C
Micheyl
Andrew J
AJ
Oxenham
D000161:Acoustic Stimulation; D000704:Analysis of Variance; D001299:Audiometry; D001306:Auditory Pathways / Q000502:physiology; D001309:Auditory Threshold; D003463:Cues; D004192:Discrimination, Psychological; D006801:Humans; D007600:Judgment; D008954:Models, Biological; D010507:Periodicity; D010897:Pitch Discrimination; D011571:Psychoacoustics; D013997:Time Factors; D013998:Time Perception