Discrimination of Ball Trajectory Using Sound of Bat Hitting in Baseball

In sports, various sounds are generated, such as the shouts of players, footsteps, and the sound of hitting the ball with a racket. In the sound of a bat hitting, differences in the intensity and pitch of the sound also appear with each batting. This paper describes an investigation and analysis of the relationship between the sound of a bat hitting and ball trajectory in baseball. In the experiments, datasets of the bat hitting sounds were constructed, and these hitting sounds were analyzed. Bat hitting sounds were recorded using a 32-bit float recording that enables recording without clipping. A total of 996 bat hitting sounds were recorded, and three types of datasets were constructed. Moreover, the ball trajectories were discriminated from a ball hitting sound using a support vector machine (SVM). In an experiment to discriminate three types of ball trajectories using SVM, an average correct rate was up to 48.4 %. The results suggest that it is possible to discriminate the ball trajectory from a bat hitting sound.