振動被曝中の聴覚音声言語および被曝後の聴覚変動
1978 年 71 巻 5special1 号 p. 607-619
詳細
1978 年 71 巻 5special1 号 p. 607-619
The effects of the whole-body vibration upon auditory and speech were examined in a series of eight experiments, in relation to the simultaneous existence or otherwise of noise. The 8 series of experiments consisted of; 1) measures of vibration which produced from vibratory tools and vibration environments, 2) effects of low-frequency vibration on man with the analysis of human body-mechanical vibratory system, 3) subjective responses to vibration, 4) minimum audible pressure level in dB SPL for pure tone (warble tone) and speech discrimation during exposure to vibration, 5) Temporary Threshold Shifts (TTS) produced following exposure to vibration, 6) fundamental pitch of Japanese vowels read by talkers under vibration, 7) vocal intensity and maximum phonation time read by talkers under vibration, and 8) monosyllablic word articulation and the sound spectrograms of the selected speech materials read by a talker under vibration. Talkers sitting erect were exposed to vertical sinusoidal vibration at low frequency in each of 5cps, 10cps, 15cps and 20cps in a controlled laboratory.
As a result from these experiments, it was found that the effects of low-frequency vibration upon auditory acuity and speech quite varied; aggravated, not changed or improved by vibration condition. The effects of whole vibration upon speech may be due to the modulation of the air passing through the mouth, and due to involuntary tightening of the abdominal, thorax and larynx muscles.
