Sound and cavity dynamics of hand clap*

A hand clap is an everyday activity for either communication or entertainment purposes. However, to the best of our knowledge, there are only a few studies that discuss the underlying principles of fluid dynamics. Pioneering works (Repp ( J. Acoust. Soc. Am., 1987) and Fletcher (Acoustics Australia, 2013)) suggested that the hand shape configuration largely determines the frequency response of the associated sound. Specifically, the volume of a cavity formed between hands is one of the primary parameters. However, the experimental data have not been provided without any systematic investigation. In this study, we used silicone rubber to craft the simplified human hand model with relatively controlled geometry to discuss the contribution of cavity dynamics to the overall sound generation process. The major experimental parameters are the cavity size and clapping speed. In addition to these controlled parameters, the alignment of the impacting hands was found to be one of the important factors. A combination of high-speed imaging and acoustic sensing allowed us to discrete sound data into regimes and like them to the clapping motion. Furthermore, we would like to report the results of the forthcoming experiment involving human subjects, which is currently planned.