Prompt transform from vibration to audible sound considering health care

摘要

The appropriate low frequency vibration is good for making a bone stronger and prenatal care. But in case that a man is continuously exposed to vibration whose center frequency is over 4Hz, various damage of health for example a stomach ulcer, backache, headache, or a jaw resonance will be possibly lead to the said man taking a long time. So if we detect unhealthy vibration soon by audibility or visibility and notify its situation to the user of vehicle, he/she can judge that he/she should not ride on its vehicle for a long time and a designer of a vehicle can decide to improve plinth by strengthen mass of chassis, lowering the center of gravity of a vehicle, fastening each parts more tightly, optimizing vibration control material at front panel, or using adaptive predicting type AVC (automatic vibration control) as designing feedback. Especially in case that we use audibility as its warning a rider or a driver can recognize it without risk by which he/she look away from front. In this study sound at which caution or safe can be recognized within 5 seconds was made by using variance of instrumental sound color and spectrum inclination and Q of sound resonance in correspondence with proportion of power whose divide is 4Hz as vibration.