Noise and vibration interactions: effects on hearing.
Auditory Research Laboratory, State University of New York, Plattsburgh, New York, Report No. ARL 88-4 1988 Dec; :1-42
Chinchillas were exposed to a 30 hertz (Hz), 3g RMS (root mean square) and a 20Hz, 1.3g RMS cage vibration combined with continuous noise at 95 decibels (dB), 0.5 kHz octave band and impact noise of 113, 119, or 125dB peak sound pressure level (SPL) for 5 days. Measurements were taken of temporary and permanent threshold shifts in hearing using evoked potentials. There was little found to distinguish the impact noise control groups on the basis of percent sensory cell loss. There was a statistically significant frequency effect for both percent inner and percent outer hair cell losses which reflected greater sensory cell losses in the mid frequency region of the cochlea where the majority of the acoustic energy of the impacts was located. The authors conclude that the two vibration alone exposures resulted in no significant audiometric changes in either the mean asymptotic threshold shift (ATS), permanent threshold shift (PTS), or percent sensory cell loss measures. The three impact noise exposure conditions produced the same levels of mean ATS, no statistically different levels of PTS or percent sensory cell loss. Some of the noise/vibration paradigms showed that such exposures did change some of the dependent measures of hearing employed. This effect was only significant for the stronger vibration exposure conditions and was particularly evident in the outer hair cell losses.
NIOSH-Grant; Noise-induced-hearing-loss; Industrial-noise; Hearing-loss; Laboratory-animals; Vibration-exposure; Sensory-thresholds; Hearing-impairment;
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 88-4
State University of New York at Buffalo, Buffalo, New York