Formation of auditory descriptions
Albert S. Bregman · The Journal of the Acoustical Society of America · 1976
In natural environments, sounds from many sources are mixed at the ear. The auditory system must parse the input to recover separate descriptions of the original sources. In addition to mechanisms for sound localization, it employs “compositional heuristics” for segregating and combining acoustic components to create a perceptual description of simultaneously active acoustic sources. The clues in the acoustic signal that indicate that components should be assigned to a single source include spectral similarity of successive components, slow and continuous changes, information for “temporary occlusion,” and, finally, synchronous and parallel changes of simultaneous components. Descriptions of multiple sources are built up simultaneously, and these descriptions compete for acoustic elements until elements are assigned as belonging to specific sources. The perception of certain qualitative features, such as timbre, depend on the perceptual grouping of components. Other perceptual consequences, such as the number of sources perceived, and the ability to judge the temporal order of elements, or to recognize patterns, also depend upon the preliminary parsing of the signal as controlled by the “compositional heuristics.” To demonstrate these effects, experiments will be described and recorded stimuli will be played.