How violinists alter sound volume and tempo when expressing bright and dark timbres

Abstract

In this paper, we report the results of our experiment conducted to reveal the effect of timbre on sounds when violinists play the violin, which we will use to improve the expression ability of our violin-playing robot to promote better human-robot interaction design. In our study, we focused on bright and dark timbres, and analyzed their effect on the sound volume and tempo of two musical pieces. The subjects were two trained violinists who are music college graduates. We chose two short musical pieces, each of which has a major and a minor key. The subjects were asked to play the violin while altering the sound volume or tempo to give bright and dark timbres to the musical pieces. We recorded the produced sounds and analyzed their sound volume and tempo. As a result, we found that the overall sound volume of bright and dark timbres is larger and smaller than normal timbres, respectively. In addition, the difference between the average and maximum sound volumes is large for dark as compared to bright timbres. Furthermore, the sound volume of one note increases gradually, while abrupt increases at the beginning and after volume change become very small. When playing to produce a bright sound, one violinist decreased the sound volume in the middle of the musical piece. Finally, we found that the tempo in a bright timbre is larger than in dark.