Auditory Processing of Complex Sounds Across Frequency Channels

摘要

The research supported by this grant is directed towards gaining an understandinghow the auditory system processes complex sounds. The results of binaural psychophysical experiments in human subjects suggest (1) that spectrally synthetic binaural processing is the rule when the number of components in the tone complex are relatively few (less than 10) and there are no dynamic binaural cues to aid segregation of the target from the background, and (2) that waveforms having large effective envelope depths are on the average more easily lateralized than those having small effective envelope depths. Psychophysical experiments in human subjects using sinusoidally amplitude modulated narrowband noises and complex patterns of modulation of tonal carriers have been directed toward understanding auditory object perception. Results from experiments and theoretical modelling suggest that slow temporal modulation of different spectral components can be used by the auditory system to fuse these components into one auditory image. The results of psychophysical experiments show that the effects of noise bandwidth on intensity discrimination of noise in chinchillas are similar to data from human subjects; the results can be accounted for by a modification of the ideal energy detector. Neurophysiological experiments have been directed at gaining an understanding of how auditory neurons encode pitch related information in the temporal properties of discharge. The results show that a temporal representation at the level of the cochlear nucleus can account for some, but not of the pitches of rippled noise. Auditory processing, hearing, complex sounds, psychophysics, neurophysiology.