The Story of the Evolution of Hearing: Identifying the Sources of Sound

Abstract

Humans have the remarkable ability to determine the sources of sounds, and in general, sound source identification appears to be the most general function of hearing and the auditory system. A century of human psychoacoustical research has revealed a wealth of information about processing the basic properties of sounds. However, far less attention has been paid to how the auditory system uses this information to determine or identify sound sources. Psychoacoustical data, models, and theories suggest that the human’s ability to resolve spectral components of complex sounds and to localize sounds could be responsible for sound source identification. But sound sources provide a number of other characteristics that could be used by an auditory system to aid it in sound source identification. A complex auditory system should be able to use these characteristics to help form auditory images of sound sources, and these auditory images would provide the basis for sound source identification. One such characteristic is the slow temporal modulation of sound generated by almost all sound sources.