title: Promoting the perception of two and three concurrent sound objects: An event-related potential study.
abstract: The auditory environment typically comprises several simultaneously active sound sources. In contrast to the perceptual segregation of two concurrent sounds, the perception of three simultaneous sound objects has not yet been studied systematically. We conducted two experiments in which participants were presented with complex sounds containing sound segregation cues (mistuning, onset asynchrony, differences in frequency or amplitude modulation or in sound location), which were set up to promote the perceptual organization of the tonal elements into one, two, or three concurrent sounds. In Experiment 1, listeners indicated whether they heard one, two, or three concurrent sounds. In Experiment 2, participants watched a silent subtitled movie while EEG was recorded to extract the object-related negativity (ORN) component of the event-related potential. Listeners predominantly reported hearing two sounds when the segregation promoting manipulations were applied to the same tonal element. When two different tonal elements received manipulations promoting them to be heard as separate auditory objects, participants reported hearing two and three concurrent sounds objects with equal probability. The ORN was elicited in most conditions; sounds that included the amplitude- or the frequency-modulation cue generated the smallest ORN amplitudes. Manipulating two different tonal elements yielded numerically and often significantly smaller ORNs than the sum of the ORNs elicited when the same cues were applied on a single tonal element. These results suggest that ORN reflects the presence of multiple concurrent sounds, but not their number. The ORN results are compatible with the horse-race principle of combining different cues of concurrent sound segregation.
authors.affiliation: Institute of Psychology and Cognitive Neuroscience, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2., Budapest, H-1117, Hungary; Department of Cognitive Science, Faculty of Natural Sciences, Budapest University of Technology and Economics, Egry József u. 1., Budapest, H-1111, Hungary. Electronic address: kocsis.zsuzsanna@ttk.mta.hu.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kocsis
authors.affiliation: Institute of Psychology and Cognitive Neuroscience, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2., Budapest, H-1117, Hungary; Institute of Psychology, University of Szeged, Egyetem u. 2., Szeged, H-6722, Hungary. Electronic address: winkler.istvan@ttk.mta.hu.
authors.forename: István
authors.initials: I
authors.lastname: Winkler
authors.affiliation: Cognitive Systems Lab, Institute of Physics, Technische Universität Chemnitz, Reichenhainer Str. 70, Chemnitz, D-09126, Germany. Electronic address: alexandra.bendixen@physik.tu-chemnitz.de.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Bendixen
authors.affiliation: Rotman Research Institute, Baycrest Centre, 3560 Bathurst Street, Toronto, Ontario M6A 2E1, Canada; Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario M5S 3G3, Canada. Electronic address: calain@research.baycrest.org.
authors.forename: Claude
authors.initials: C
authors.lastname: Alain
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult
keywords: Concurrent sound segregation; Cue combinations; Object-related negativity (ORN); Three simultaneous sound objects