抄録
Batting sound of a metal baseball bat and a ball is discussed in this paper. The frequency of the sound is analysed and four resonance frequencies are measured for a sample bat. First two frequencies dominates the batting sound, so frequency ratio between two frequecies, difference of the amplitude at the resonance frequency, and damping coefficient for each resonance are examined in psychological tests to determine comfortable sound. Conssonant sound between two frequencies is better than dissonant sound even for impulsive sound. Suitable amplitude and suitable damping coefficient are also obtained by the experiment. In order to achieve the comfortable batting sound, the thickness of the bat was analysed and small modification is enough to improve the batting sound. It is also asserted that this modification does not effect on the the restitution coefficient.
