Previous work with cats has shown that functional changes in central auditory mechanisms follow sound-induced hearing loss or mechanical destruction of the cochleas. The functional changes include a virtual elimination of temporal summation for electrical stimulation of cochlear nucleus. A power function model, in contrast to an exponential model, has proved useful in describing temporal summation in normal-hearing and hearing-impaired human subjects. This same model can also characterize temporal summation data obtained with electrical stimulation of cochlear nucleus in normal-hearing cats and in cats with mechanically destroyed cochleas. The objective of the proposed work is to test the hypothesis that there are at least two sites of temporal summation--one of these sites being within the cochlea, while other summation processes reside in central auditory mechanisms. In normal-hearing cats, temporal summation will be measured using operant behavioral procedures both with acoustic stimuli and with electrical stimulation of auditory brainstem nuclei. In addition to type (auditory/electrical) and site (peripheral/central) of stimulation, sound-induced hearing-loss will be used to alter the operation of the summation processes. The use of a single species in the proposed work is important in order to probe the nature of the interrelated operations underlying auditory temporal summation. Knowledge concerning central involvement following hearing loss may prove to be of importance in the design of hearing aids, in the interpretation of evoked response data, and in the search for a useful cochlear prosthesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS019512-02
Application #
3399573
Study Section
Hearing Research Study Section (HAR)
Project Start
1985-01-01
Project End
1987-12-31
Budget Start
1986-01-01
Budget End
1986-12-31
Support Year
2
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Texas-Dallas
Department
Type
Other Specialized Schools
DUNS #
City
Richardson
State
TX
Country
United States
Zip Code
75080