Auditory scene analysis: Examining the role of nonlinguistic auditory processing in speech perception
Elyse Sussman
(Yeshiva University, Albert Einstein College of Medicine, New York)

Event-related brain potentials were used to investigate whether auditory stream segregation processes occur without attention focused on the sounds and to assess the effects of attention on segregation and grouping processes. In one set of studies, a sequence of alternating high and low frequency sounds was arranged so that when the sounds segregated a 3 tone rising pattern emerged separately in each frequency stream. Segregation of the sounds was induced either by manipulating the stimulus-driven factors of the sound sequence (Exp. 1) or by manipulating the subject’s task and not the sound sequence (Exp. 2). Pattern violations were detected when the sounds segregated, both when brought about by stimulus-driven factors and by attentional control. The results demonstrate that auditory memory can hold information about multiple sound streams and that attention can affect the formation of auditory streams. In another study, we measured the time course of auditory change detection. Sound change, an important cue used in analyzing the continually changing auditory scene, sometimes signals the start of new sources of information or a call for some action. We found that the brain’s response to the same stimulus event differed depending on the auditory context within which it occurred (brought about by the onset or cessation of a sound in the stimulus block), suggesting the existence of a dynamic system of change detection process that updates the neural model of the sensory input on line as the changes occur.

Supporting material:

Elyse Sussman and I Winkler (2001) Dynamic sensory updating in the auditory system. Cognitive Brain Research 12, 431–439.

Elyse Sussman, W Ritter and HG Vaughan, Jr. (1999). An investigation of the auditory streaming effect using event-related brain potentials. Psychophysiology, 36, 22–34.

Elyse Sussman W Ritter and HG Vaughan, Jr. (1998). Attention affects the organization of auditory input associated with the mismatch negativity system. Brain Research, 789, 130–138.