ASA 125th Meeting Ottawa 1993 May

4pMU8. Acoustics of a Chinese hand-exercise ball.

Edward R. Mansell

Thomas D. Rossing

Phys. Dept., Northern Illinois Univ., DeKalb, IL 60115

Pairs of steel balls, 3--4 cm in diameter, have been used in China as hand exercisers since the time of the Ming dynasty. Often a sounding device, consisting of a coil spring and a small steel ball, is placed inside the balls to produce a rather delicate tinkling sound as the balls are moved in circles in the hand. It is claimed that the balls can produce sounds ``which are like the whistling of a dragon and singing of a phoenix.'' The sound spectrum shows many strong partials up to 10 kHz or higher. The most identifiable pitch of G[sub 5] results from a partial at 773 Hz.