Dissociation of perceptual judgments of "what" and "where" in an ambiguous auditory scene.

Whenever an acoustic scene contains a mixture of sources, listeners must segregate the mixture in order to compute source content and/or location. Some past studies have explored whether perceived location depends on which sound elements are perceived within a source. However, no direct comparisons have been made of "what" and "where" judgments for the same sound mixtures using the same listeners. The current study tested if the sound elements making up an auditory object predict that object's perceived location. Listeners were presented with an auditory scene containing competing "target" and "captor" sources, each of which could logically contain a "promiscuous" tone complex. In separate blocks, the same listeners matched the perceived spectro-temporal content ("what") and location ("where") of the target. Generally, as the captor intensity decreased, the promiscuous complex contributed more to both what and where judgments of the target. However judgments did not agree either quantitatively or qualitatively. For some subjects, the promiscuous complex consistently contributed more to the spectro-temporal content of the target than to its location while for some it consistently contributed more to target location. These results show a dissociation between the perceived spectro-temporal content of an auditory object and where that object is perceived.