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A sound element gets lost in perceptual competition
Barbara G Shinn-Cunningham1, Adrian K C Lee, Andrew J Oxenham
1Boston University Hearing Research Center, 677 Beacon Street, Boston, MA 02215, USA. shinn@cns.bu.edu
Summary
Auditory perception relies on separating sounds. A new "nonallocation" effect shows a sound element can disappear when two auditory objects compete for it, impacting complex sound scene processing.
Area of Science:
- Auditory Neuroscience
- Psychoacoustics
- Perceptual Psychology
Background:
- Auditory scene analysis involves separating concurrent sounds into distinct objects.
- The principle of disjoint allocation suggests sound elements typically belong to one object.
- Exceptions like duplex perception (coallocation) exist where elements are shared.
Purpose of the Study:
- To investigate the phenomenon of "nonallocation" in auditory perception.
- To explore conditions where a sound element is not perceived as part of any auditory object.
- To examine the asymmetry in perceptual evidence for including versus excluding elements in auditory objects.
Main Methods:
- Presenting a target tone within sequences of tones or with a harmonic vowel complex.
- Manipulating the spatial configuration of auditory objects.
- Assessing target tone perception within competing auditory streams.
Main Results:
- A target tone is perceived as part of its stream (tones or vowel) when presented alone.
- When target, tones, and vowel are presented together with specific spatial configurations, the target may not be perceived.
- The target is not perceived as a separate entity but disappears from both competing objects.
Conclusions:
- The study reveals a novel
- nonallocation
- effect in auditory perception.
- Findings suggest an asymmetry in the perceptual evidence needed to reject versus include sound elements.
- This has implications for understanding how the brain processes ambiguous information in complex auditory scenes.
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