HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 93/6/3050    most recent 00985.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (37) Citing Articles via Google Scholar Google Scholar Articles by Zeng, F.-G. Articles by Starr, A. Search for Related Content PubMed PubMed Citation Articles by Zeng, F.-G. Articles by Starr, A.

TRANSLATIONAL PHYSIOLOGY

Perceptual Consequences of Disrupted Auditory Nerve Activity

¹Departments of Anatomy and Neurobiology, ²Biomedical Engineering, ³Cognitive Sciences, ⁴Neurology, and ⁵Otolaryngology–Head and Neck Surgery, University of California, Irvine, California

Submitted 21 September 2004; accepted in final form 17 December 2004

Perceptual consequences of disrupted auditory nerve activity were systematically studied in 21 subjects who had been clinically diagnosed with auditory neuropathy (AN), a recently defined disorder characterized by normal outer hair cell function but disrupted auditory nerve function. Neurological and electrophysical evidence suggests that disrupted auditory nerve activity is due to desynchronized or reduced neural activity or both. Psychophysical measures showed that the disrupted neural activity has minimal effects on intensity-related perception, such as loudness discrimination, pitch discrimination at high frequencies, and sound localization using interaural level differences. In contrast, the disrupted neural activity significantly impairs timing related perception, such as pitch discrimination at low frequencies, temporal integration, gap detection, temporal modulation detection, backward and forward masking, signal detection in noise, binaural beats, and sound localization using interaural time differences. These perceptual consequences are the opposite of what is typically observed in cochlear-impaired subjects who have impaired intensity perception but relatively normal temporal processing after taking their impaired intensity perception into account. These differences in perceptual consequences between auditory neuropathy and cochlear damage suggest the use of different neural codes in auditory perception: a suboptimal spike count code for intensity processing, a synchronized spike code for temporal processing, and a duplex code for frequency processing. We also proposed two underlying physiological models based on desynchronized and reduced discharge in the auditory nerve to successfully account for the observed neurological and behavioral data. These methods and measures cannot differentiate between these two AN models, but future studies using electric stimulation of the auditory nerve via a cochlear implant might. These results not only show the unique contribution of neural synchrony to sensory perception but also provide guidance for translational research in terms of better diagnosis and management of human communication disorders.

This article has been cited by other articles:

				S. L. Phillips, S. J. Richter, and D. McPherson Voiced Initial Consonant Perception Deficits in Older Listeners With Hearing Loss and Good and Poor Word Recognition J Speech Lang Hear Res, February 1, 2009; 52(1): 118 - 129. [Abstract] [Full Text] [PDF]

				A. J. Oxenham Pitch Perception and Auditory Stream Segregation: Implications for Hearing Loss and Cochlear Implants Trends in Amplification, December 1, 2008; 12(4): 316 - 331. [Abstract] [PDF]

				G. Rance, R. Fava, H. Baldock, A. Chong, E. Barker, L. Corben, and M. B. Delatycki Speech perception ability in individuals with Friedreich ataxia Brain, August 1, 2008; 131(8): 2002 - 2012. [Abstract] [Full Text] [PDF]

				F.-G. Zeng and S. Liu Speech perception in individuals with auditory neuropathy. J Speech Lang Hear Res, April 1, 2006; 49(2): 367 - 380. [Abstract] [Full Text] [PDF]

				W. Tang, Y. Zhang, Q. Chang, S. Ahmad, I. Dahlke, H. Yi, P. Chen, D. L. Paul, and X. Lin Connexin29 Is Highly Expressed in Cochlear Schwann Cells, and It Is Required for the Normal Development and Function of the Auditory Nerve of Mice J. Neurosci., February 15, 2006; 26(7): 1991 - 1999. [Abstract] [Full Text] [PDF]

				D. Gothelf, N. Farber, E. Raveh, A. Apter, and J. Attias Hyperacusis in Williams syndrome: Characteristics and associated neuroaudiologic abnormalities Neurology, February 14, 2006; 66(3): 390 - 395. [Abstract] [Full Text] [PDF]

				D. Oertel Importance of Timing for Understanding Speech. Focus on "Perceptual Consequences of Disrupted Auditory Nerve Activity" J Neurophysiol, June 1, 2005; 93(6): 3044 - 3045. [Full Text] [PDF]