The relation between hearing loss, sensory cell loss and tuning characteristics in the chinchilla.
Auditory Research Laboratory, State University of New York, Plattsburgh, New York, Report No. ARL 88-5 1988 Dec:363 pages
Chinchillas were exposed to acoustic overstimulation to determine the effects of change in frequency selectivity to sensory cell loss. Each animal was exposed to 0.5, 1.0, 2.0, 4.0, 8.0 and 11.2 kilohertz (kHz), and measures of auditory thresholds and masked thresholds were taken using the auditory evoked potential recorded from the inferior colliculus. A comparison was made of three tuning curve variables to the amount of noise induced permanent threshold shift and to the percent sensory cell loss produced by a variety of noise exposures. Frequencies which showed permanent threshold shifts in excess of 10 decibels (dB) also demonstrated statistically significant differences between preexposure and postexposure measures of all three tuning curve variables. Statistically significant changes in the tuning curve variables did not result from shifts of less than 10dB. Systematic and parallel increases were demonstrated in the percentage of outer hair cell loss and percentage change in tuning curve characteristics as threshold shifts increased at all probe tone frequencies except 8,0 and 11.2kHz. The authors conclude that these findings support the concept of a systematic change in the variables which define the quality of tuning as hearing loss progressively increases and that these changes are clearly related to outer hair cell losses.
NIOSH-Grant; Noise-induced-hearing-loss; Industrial-noise; Noise-exposure; Cell-function; Cell-damage; Hearing-impairment; Laboratory-animals
Communicative Disorders & Scis Research Foundation of Suny P O Box 9 Albany, N Y 12201
Final Grant Report
Auditory Research Laboratory, State University of New York, Plattsburgh, New York, Report No. ARL 88-5
State University of New York at Buffalo, Buffalo, New York