The major objective is to determine the appropriateness and the limitations of the Mongolian gerbil as an animal model of presbyacusis. This is achieved, in part, by monitoring some of the properties of auditory electrical potentials recorded from awake and sedated animals who have been born and reared in an acoustically controlled environment. Of especial interest are auditory potentials arising from the auditory nerve and brainstem and their age-related declines as indicated by auditory sensitivity, amplitude-intensity and latency-intensity functions, and measures of frequency selectivity. A second objective is to assess interactions between hearing loss associated with aging and the hearing loss produced by exposure to low and moderate levels of noise. Noise levels range from 65 to 98 dBA, and exposure durations from 10 days to 2.5 yrs. Of specific interest is the determination of the relations between the magnitude of the hearing loss and the level of the noise for short-duration exposures, long-duration exposures which occur prior to the onset of aging effects, and long-duration exposures where age- related interactions occur. Animals from this project are the experimental animals of Project #3, 4 and 5 on cochlear pathophysiology, histopathology, and histochemistry. Results of the proposed experiments are pertinent to diagnostic and rehabilitative procedures in noise-induced hearing loss and presbyacusis as well to theoretical issues in audition and in the neurosciences.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Specialized Center (P50)
Project #
5P50NS025039-02
Application #
3923448
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Medical University of South Carolina
Department
Type
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29425
Schum, D J; Matthews, L J (1992) SPIN test performance of elderly hearing-impaired listeners. J Am Acad Audiol 3:303-7
Schum, D J (1992) Responses of elderly hearing aid users on the hearing aid performance inventory. J Am Acad Audiol 3:308-14
Schum, D J; Matthews, L J; Lee, F S (1991) Actual and predicted word-recognition performance of elderly hearing-impaired listeners. J Speech Hear Res 34:636-42
Schmiedt, R A; Mills, J H; Adams, J C (1990) Tuning and suppression in auditory nerve fibers of aged gerbils raised in quiet or noise. Hear Res 45:221-36
Schum, D J; Collins, M J (1990) The time course of acoustic/phonemic cue integration in the sensorineurally hearing-impaired listener. J Acoust Soc Am 87:2716-28
Mills, J H; Schmiedt, R A; Kulish, L F (1990) Age-related changes in auditory potentials of Mongolian gerbil. Hear Res 46:201-10
Schum, D J (1990) Noise reduction strategies for elderly, hearing-impaired listeners. J Am Acad Audiol 1:31-6
Schmiedt, R A (1990) Intermodulation distortion in the cochlea as shown by offset action potential (AP) masking curves. J Acoust Soc Am 87:1357-9
Klein, A J; Mills, J H; Adkins, W Y (1990) Upward spread of masking, hearing loss, and speech recognition in young and elderly listeners. J Acoust Soc Am 87:1266-71
Smith, D I; Mills, J H; Schmiedt, R A (1990) Frequency selectivity of the middle latency response. Hear Res 43:95-105

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