The auditory organization of speech and other sources in listeners and computational models

Speech is typically perceived against a background of other sounds. Listeners are adept at extracting target sources from the acoustic mixture reaching the ears. The auditory scene analysis (ASA) account holds that this feat is the result of a two-stage process. In the first-stage, sound is decomposed into collections of fragments in several dimensions. Subsequent processes of perceptual organization reassemble these fragments, based on cues indicating common source of origin which are interpreted in the light of prior experience. In this way, the decomposed auditory scene is processed to extract coherent evidence for one or more sources. Auditory scene analysis in listeners has been studied for several decades and recent years have seen a steady accumulation of computational models of perceptual organization. The purpose of this review is to describe the evidence for the nature of auditory organization in listeners and to explore the computational models which have been motivated by such evidence. The primary focus is on speech rather than on sources such as polyphonic music or non-speech ambient backgrounds, although all these domains are equally amenable to auditory organization. The review includes a discussion of the relationship between auditory scene analysis and alternative approaches to sound source segregation. (C) 2001 Elsevier Science B.V. All rights reserved.