振動, 騒音の一過性聴力損失に及ぼす影響

抄録

Relationship among vibration, noise and hearing loss in human beings was investigated.
Significant hearing loss as an auditory temporary threshold shift was not observed in cases exposed to the vibration of acceleration 100cm/sec² and frequency either 2c/s, 5c/s or 10c/s. On the contrary, in those exposed to that of 500cm/sec² and 5c/s which is regarded as the resonance frequency of human body, statistically significant (5%) hearing loss was observed at 4kc. Heavier hearing loss was noticed at 4kc and 1kc in cases exposed to that of 500cm/sec² and 5c/s with a steady noise (all pass 101dB) than in those exposed to the noise only. It is, therefore, apparent that noise induced hearing loss may be aggravated by vibration. As the vibration induced hearing loss was noticed at 1kc, the authors newly indicated that proper hearing protection at 1kc would be also quite necessary in works with both noise and vibration.