Spatial aspects of acoustic processing in complex environments.

Abstract

From the perspective of acoustical signal processing, it is a challenge to analyze a complex sound environment and segregate the acoustic mixture into individual sources, each with its own spatial characteristics and reverberation pattern. However, auditory systems perform this perceptually critical task with impressive ease. This talk will review how acoustical array processors work to separate sound sources. We then consider what most vertebrates, who have two point receivers separated in space, can accomplish by combining the signals that reach their two ears. The nature of the information available to bird and mammalian auditory systems is briefly reviewed, and the computational approaches these systems take to separating sound sources is assessed, including the logic of processing sound within narrow frequency channels over brief time epochs (rather than, e.g., undertaking broadband analysis). Some observations about the ability of classical binaural processing models to implement earlier stages of processing for these complex environments will be discussed. Finally, performance of human and zebra‐finch subjects in tasks requiring judgments about individual sources embedded in complex sound mixtures will be considered in the context of physiologically motivated processing schemes. [Work supported by NIDCD: DC00100 (Colburn), DC05778 (Shinn‐Cunningham), and DC07610 (Sen).]