| 摘要 |
PURPOSE: To control to reduce undesirable body propagating audio noise by setting in a container at least one vibrator to give ultrasonic vibration to the working liquid with a specific frequency band and a specific power intensity, detecting the body propagating audio sound through the working liquid in the container, and changing the subharmonic added on the working liquid. CONSTITUTION: Ultrasonic vibration is sent with a partial power intensity of 0.1-30 watt per square centimeter through a working liquid 18 in the first period when animal body is not soaked with the working liquid yet, by which an ultrasonic wave is applied on a part of the body through the working liquid with a frequency in the range from 15kHz to 100kHz at the step to sterilize the liquid, another step to soak a part of the animal body to have acoustic contact with the liquid in the second period different from the first period, and during the second period. Undesirable body propagating audio noise can be reduced by changing at least one of the following, namely, the shape of the vibrators in the container 16, the size of at least one of the vibrators, and the position of one of the vibrators. |
