The development of an automated striking device for repeatable percussion strikes

Abstract

Many high-quality directivity systems involve a single microphone arc which rotates around a sound source. Since multiple data captures are necessary as the arc rotates around a sound source, the source should emit the sound in a steady and repeatable way at all arc positions. To obtain directivity measurements of a struck percussion instrument, it is crucial to be able to strike the instrument during each microphone arc position as consistently as possible. However, a human player typically cannot strike the instrument in the exact same way for many consecutive measurements. To overcome the shortcomings of human players, an automatic striking device was developed to aid in the study of the directivity of percussion instruments. The device consists of a striking implement holder attached to a stepper motor that is controlled by an Arduino. The striking implement holder allows the user of the striking device to use different-sized mallets/drumsticks depending on the instrument that is being measured. The automatic striking device has been used to obtain directivity measurements on several instruments including a glockenspiel, cymbal, and drum. The details of the automatic striking device will be presented along with a subset of directivity results.