Forming auditory objects in a reverberant cocktail party setting

Abstract

Event Abstract Back to Event Forming auditory objects in a reverberant cocktail party setting Sandra H. Blumenrath1* and Robert J. Dooling1 1 University of Maryland, College Park, United States In multi-signaler environments, listeners are faced with the challenge to selectively attend to and follow sound sequences of one sender while disregarding those of others. As a solution to the so-called “Cocktail Party” problem, the auditory system has to group sound components from one source into a single object based on specific unifying physical features, while at the same time separating them from components from other sources with different unifying features. Some of the grouping cues are common onset and offset times, common amplitude modulations, as well as similar frequency ranges and spatial origins. Although the integration and segregation of auditory objects is aided by such cues, successful object formation may be compromised in natural environments where vocal signals are reverberated. In a cacophony of reverberated stimuli, tails of echoes and the interaction between direct and reflected sound waves can, for instance, obliterate sharp onset and offset times and alter both the temporal and spectral patterns of sounds. The goal of this study was to investigate the effect of reverberation on behavioral measures of auditory object formation under conditions with increasing numbers of simultaneous signalers. We designed a psychophysical experiment with budgerigars, canaries, and zebra finches, in which subjects were tested with natural vocalizations from all three species. Tests involved a GO/NOGO procedure, in which the birds had to keep responding throughout one of two previously learned, 4-s long song sequences (GO vs. NOGO song) either in the absence (control) or presence of other superimposed songs from one, two, or four different individuals. The GO and NO GO song differed only towards the end, which forced the birds to attend to the entire song sequence. In the case of a NOGO song the birds would stop responding towards the end. A complete object was formed if correct responses (GO or NOGO) were given to either of these two sequence. Results showed clear independent effects of reverberation time, number of simultaneously singing individuals, and vocalization type. Most importantly, the birds’ ability to selectively attend to a specific sequence of sounds was particularly compromised when very high reverberation times coincided with many birds singing in the background, indicating a synergistic effect between the two factors. In contrast, neither of these factors alone decreased the birds’ sensitivity to or below threshold. Budgerigars generally outperformed both canaries and zebra finches and also showed a clear advantage when tested with conspecific song. These results revealed that in a cocktail party environment with multiple signalers, sound reverberation plays a critical role in affecting the percept of distinct auditory objects and renders identification of individual sound sources more difficult. The degree to which auditory stream segregation is compromised, however, depends on the amount of reverberation as well as the number of signaling individuals. Keywords: auditory object formation, auditory scene analysis, bird vocalizations, Birds, environmental acoustics, Psychoacoustics, reverberation Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster Presentation (see alternatives below as well) Topic: Sensory: Audition Citation: Blumenrath SH and Dooling RJ (2012). Forming auditory objects in a reverberant cocktail party setting. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00061 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 May 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Sandra H Blumenrath, University of Maryland, College Park, College Park, MD, 20742, United States, shb@umd.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Sandra H Blumenrath Robert J Dooling Google Sandra H Blumenrath Robert J Dooling Google Scholar Sandra H Blumenrath Robert J Dooling PubMed Sandra H Blumenrath Robert J Dooling Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.