title: Induced Loudness Reduction and Enhancement in Acoustic and Electric Hearing.
abstract: The loudness of a tone can be reduced by preceding it with a more intense tone. This effect, known as induced loudness reduction (ILR), has been reported to last for several seconds. The underlying neural mechanisms are unknown. One possible contributor to the effect involves changes in cochlear gain via the medial olivocochlear (MOC) efferents. Since cochlear implants (CIs) bypass the cochlea, investigating whether and how CI users experience ILR should help provide a better understanding of the underlying mechanisms. In the present study, ILR was examined in both normal-hearing listeners and CI users by examining the effects of an intense precursor (50 or 500 ms) on the loudness of a 50-ms target, as judged by comparing it to a spectrally remote 50-ms comparison sound. The interstimulus interval (ISI) between the precursor and the target was varied between 10 and 1000 ms to estimate the time course of ILR. In general, the patterns of results from the CI users were similar to those found in the normal-hearing listeners. However, in the short-precursor short-ISI condition, an enhancement in the loudness of target was observed in CI subjects that was not present in the normal-hearing listeners, consistent with the effects of an additional attenuation present in the normal-hearing listeners but not in the CI users. The results suggest that the MOC may play a role but that it is not the only source of these loudness context effects.
authors.affiliation: Department of Psychology, University of Minnesota, N218 Elliott Hall, 75 East River Rd., Minneapolis, MN, 55455, USA. wang2087@umn.edu.|Nurotron Biotechnology Co., Ltd, Hangzhou, Zhejiang, China. wang2087@umn.edu.
authors.forename: Ningyuan
authors.initials: N
authors.lastname: Wang
authors.affiliation: Department of Otolaryngology, University of Minnesota, Rm 8-323 Phillips Wangensteen Building, 420 Delaware St. SE, Minneapolis, MN, 55455, USA.
authors.forename: Heather
authors.initials: H
authors.lastname: Kreft
authors.affiliation: Department of Psychology, University of Minnesota, N218 Elliott Hall, 75 East River Rd., Minneapolis, MN, 55455, USA.|Department of Otolaryngology, University of Minnesota, Rm 8-323 Phillips Wangensteen Building, 420 Delaware St. SE, Minneapolis, MN, 55455, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Oxenham
mesh_terms: D000328:Adult; D003054:Cochlear Implants; D005260:Female; D006309:Hearing; D006801:Humans; D008144:Loudness Perception; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: auditory context effects; cochlear implants; loudness; loudness recalibration