Dissociation of perceptual judgments of “what” and “where” in an ambiguous auditory scene

Abstract

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.

Fusion of spatially separated vowel formant cues

“…However, the result cannot be generalized to cover all vowels as only the vowel /ae/ was applied to study this aspect in the test. When the two components were presented with the axis of symmetry along the side of the listener, the perceived direction of the vowel was found to follow the direction of the frontmost component, and to lie between the directions of the two components, which is in accordance with the "consistent-object" hypothesis (Schwartz and Shinn-Cunningham, 2010;Best et al, 2007).…”

“…If the components are fully fused, only one auditory event is perceived. According to the "consistent-object" hypothesis (Schwartz and Shinn-Cunningham, 2010), the perceived direction of the vowel should then fall between the directions from which the two components are presented (Best et al, 2007). Then again, the study may indicate that duplex perception occurs as one of the components contributes to the identification of the vowel and is at the same perceived as an additional auditory event.…”

Predictability effects in auditory scene analysis: a review

“…Näätänen and Picton ( 1987 ) coined the terms temporal uncertainty and event uncertainty to emphasize the qualitative difference between temporal regularities (reflecting the when aspect) and feature regularities (reflecting the what aspect; see also recent work by Sperduti et al, 2011 ; Arnal and Giraud, 2012 ; Hughes et al, 2013 ; Schwartze et al, 2013 ). Location, reflecting the where aspect, may constitute yet another qualitatively different feature (Rauschecker and Tian, 2000 ; Schwartz and Shinn-Cunningham, 2010 ). Thus, although the different features were initially treated as somewhat interchangeable to demonstrate the general principle of predictability effects in ASA, their specific effects should be disentangled in future studies (for an analogy in simultaneous ASA, see Kitterick et al, 2010 ).…”

Attention, Awareness, and the Perception of Auditory Scenes

“…Change deafness is the surprising failure to notice striking changes to auditory scenes. A visual analog to this phenomenon has been extensively studied in the visual domain, where it is referred to as change blindness (for reviews, see Rensink, 2002 ; Simons and Rensink, 2005 ). And a related auditory phenomenon was actually demonstrated as early as the work of Cherry ( 1953 ) who showed that changes to an unattended stream of auditory input (such as a change of the speaker’s identity) are often missed while shadowing a spoken message presented to an attended stream of auditory input (Vitevitch, 2003 ; Sinnett et al, 2006 ).…”