title: Contralateral masking in bilateral cochlear implant patients: a model of medial olivocochlear function loss.
abstract: Contralateral masking is the phenomenon where a masker presented to one ear affects the ability to detect a signal in the opposite ear. For normal hearing listeners, contralateral masking results in masking patterns that are both sharper and dramatically smaller in magnitude than ipsilateral masking. The goal of this study was to investigate whether medial olivocochlear (MOC) efferents are needed for the sharpness and relatively small magnitude of the contralateral masking function. To do this, bilateral cochlear implant patients were tested because, by directly stimulating the auditory nerve, cochlear implants circumvent the effects of the MOC efferents. The results indicated that, as with normal hearing listeners, the contralateral masking function was sharper than the ipsilateral masking function. However, although there was a reduction in the magnitude of the contralateral masking function compared to the ipsilateral masking function, it was relatively modest. This is in sharp contrast to the results of normal hearing listeners where the magnitude of the contralateral masking function is greatly reduced. These results suggest that MOC function may not play a large role in the sharpness of the contralateral masking function but may play a considerable role in the magnitude of the contralateral masking function.
authors: Department of Speech and Hearing Science, University of Illinois at Urbana-Champaign, Champaign, Illinois, United States of America; Communication and Neuroscience Division, House Research Institute, Los Angeles, California, United States of America.
authors: Justin M
authors: JM
authors: Aronoff
authors: Communication and Neuroscience Division, House Research Institute, Los Angeles, California, United States of America; Department of Otolaryngology, New York University, New York, New York, United States of America.
authors: Monica
authors: M
authors: Padilla
authors: Communication and Neuroscience Division, House Research Institute, Los Angeles, California, United States of America; Department of Head and Neck Surgery, University of California Los Angeles, Los Angeles, California, United States of America.
authors: Qian-Jie
authors: QJ
authors: Fu
authors: Communication and Neuroscience Division, House Research Institute, Los Angeles, California, United States of America; Department of Otolaryngology, New York University, New York, New York, United States of America.
authors: David M
authors: DM
authors: Landsberger
mesh_terms: D000368:Aged; D003051:Cochlea / Q000503:physiopathology; D019929:Cochlear Implantation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009847:Olivary Nucleus / Q000503:physiopathology; D010470:Perceptual Masking