Binding the acoustic features of an auditory source through temporal coherence

Abstract

Numerous studies have suggested that the perception of a target sound source can only be segregated from a complex acoustic background if the acoustic features underlying its perceptual attributes (e.g., pitch, location, and timbre) induce temporally modulated responses that are mutually correlated, and that are uncorrelated from those of other sources in the mixture. This "temporal coherence" hypothesis asserts that listening attentively to one or a subset of attributes of a target source enhances their neural responses and concomitantly enhances all other coherent responses, thus binding them together while simultaneously suppressing the incoherent responses to the background features. Here we report on EEG measurements in human subjects engaged in various sound segregation tasks that demonstrate rapid binding among the temporally coherent features of the attended source regardless of their identity, harmonic relationship, or frequency separation, thus confirming the key role temporal coherence plays in the organization of auditory scenes.