抄録
The intrinsically peaceful sound of the water musical instrument derives from the air-bubbles formed by the impact of the water droplets on the water surface. Thus the control of the air-bubbles is the key to the tonal quality. Our study is focused on the influences of the length of the tube sunk under the water surface and water depth on the sound radiated from a water musical instrument. It has been done through the simultaneous measurement of both the generated sound and the process of the formation and collapse of the air-bubbles. When the pipe is immersed deeper in the water, the column of air-bubble becomes longer and the dominant frequency of the sound source based on the bubble vibration is shifted to the lower. And when the water depth becomes shallower, the vibration caused by air bubbles is generated later, and the dominant generated sound is shifted to the higher frequency accordingly.