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Impulse noise induced hearing loss from simulated work-week exposures.
Henderson-D; Hamernik-RP; Hynson-K
Department of Otolaryngology and Communication Sciences, State University of New York, Upstate Medical Center, Syracuse, New York, 1981 Jan; :1-25
After preexposure thresholds had been determined, six adult monaural chinchillas were exposed to a repetitive, reverberant impulse for 8 hours per day, for 5 days. The noise impulses were produced by two automated, cam driven, brass hammers hitting a steel plate. Thresholds were measured at 0.25, 0.5, 1, 2, 4, and 8 kilohertz (kHz) 0.5 hour before and 0.5 hour after each of the five 8 hour exposures. After the last exposure the recovery of threshold was monitored for 5 successive days. Final hearing thresholds were obtained starting at 30 days postexposure and were either the average of 3 days of averaged evoked response (AER) testing or 10 days of behavioral testing. The AER thresholds were systematically higher than the behavioral thresholds by 5 to 18 decibels. All frequencies were shifted by approximately the same amount by the end of the 5 day exposure as they were at the end of the first day's exposure, and there was no cumulative effect. There was still some residual threshold shift with 2 days' recovery. The actual degree of oscillation of threshold presumably would be a function of the actual noise exposure as well as the acoustic environment during recovery.
NIOSH-Grant; Noise-induced-hearing-loss; Laboratory-animals; Sensory-thresholds; Hearing-threshold
Otolaryngology Upstate Medical Center Departm 750 E Adams Street Syracuse, N Y 13210
Final Grant Report
NTIS Accession No.
Department of Otolaryngology and Communication Sciences, State University of New York, Upstate Medical Center, Syracuse, New York
Upstate Medical Center, Syracuse, New York
Page last reviewed: April 12, 2019
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