| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2001: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
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| Research Abstract |
Although pneumatic system are suitable for assistance to man, pneumatic noise generated from the system jars on us. The pneumatic noise such as jet noise from discharged air and the noise reduced by silencer is generally evaluated by A-weighted sound pressure level. We, however, feel that the noise decreased the level is loud.
In this work, the noise evaluation method utilized electroencephalogram i.e. EEG is proposed. EEG was measured by ten-twenty electrode system. Alpha wave was observed on the occipital when experimental subjects sat down and relaxed in the noise measuring room. During the stimulation of the pneumatic noise, alpha wave was disappeared and beta wave was appeared on the frontal and the central. Loudness is projected on beta wave. For steady noise, relationship between average of electric potential of beta wave and sound pressure was obtained by steavns power function. The expression can be estimate the loudness of pneumatic noise.
Furthermore, the pneumatic noise was studied from physiological view. Heart rate, hidrosis, and respiratory of man were measured. Heart rate, coefficients of R-R interval variation, and respiration were increased when experimental subjects were heard the pneumatic noise. Mental sweating was also observed. Explanations based on function of the brain are given. It is cleared that autonomic functions are influenced by the pneumatic noise.
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