The Precedence Effect as a Dynamic Process
{'Code': '04040500', 'Directorate': {'Abbreviation': 'SBE', 'LongName': 'Direct For Social, Behav & Economic Scie'}, 'Division': {'Abbreviation': 'BCS', 'LongName': 'Division Of Behavioral and Cognitive Sci'}}
{'SignBlockName': 'Jasmine Young', 'PO_EMAI': 'jyoung@nsf.gov', 'PO_PHON': '7032924833'}
A series of experiments will investigate adults' perception of an               auditory phenomenon known as the precedence effect.  The                        precedence effect occurs when two identical sounds are delivered                from two spatial locations (e.g., two loudspeakers), with the                   onset of one leading the other by a few thousandths of a second.                The listener localizes the sound solely at the leading location                 and does not hear the sound at the lagging location at all.  When               the time delay between onsets is increased, the echo threshold is               reached and the lagging sound is heard as an echo.  The                         precedence effect is due to the nervous system's active                         suppression of the echoes.  These experiments will be directed                  toward establishing the conditions under which this suppression                 breaks down.  Previous work has shown that a sudden switch in the               location of leading and lagging sound will break down the                       suppression.  These experiments will explore whether the presence               of the echo before the switch is necessary and whether only the                 leading (or lagging) sound being changed in location is                         sufficient to break the suppression.  Acoustic characteristics of               the sound, such as intensity and frequency, will be varied to                   determine how they affect suppression.  Inhibition of echoes is a               critical feature of everyday listening in normal settings.                      Without echo suppression, it would be very difficult to detect                  the original source of a sound, leading to confusion of sound                   sources.  Because the precedence effect is an inhibitory process                of the central nervous system, brain damage produced by lesions                 or strokes could impair a person's ability to localize sound.                   Better understanding of the precedence effect and the stimulus                  conditions affecting it has relevance for theories of binaural                  hearing and has practical implications for patients with damage                 in the auditory areas of the brain.
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{'Name': 'University of Massachusetts Amherst', 'CityName': 'AMHERST', 'ZipCode': '010039252', 'PhoneNumber': '4135450698', 'StreetAddress': '101 COMMONWEALTH AVE', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Massachusetts', 'StateCode': 'MA', 'CONGRESSDISTRICT': '02', 'CONGRESS_DISTRICT_ORG': 'MA02', 'ORG_UEI_NUM': 'VGJHK59NMPK9', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF MASSACHUSETTS', 'ORG_PRNT_UEI_NUM': None}
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{'Code': '118000', 'Text': 'HUMAN COGNITION & PERCEPTION'}
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