Acoustical studies of Japanese traditional drums (Tsuzumi)—Vibration, analysis, and synthesis

First, properties of vibrations on the membranes of Tsuzumi (Japanese traditional drums) are reviewed. There are two kinds of Tsuzumi, Ootsuzumi and Kotsuzumi, that have features different from each other. It is mentioned that the vibrational frequencies of Ootsuzumi may approximate ratios of the roots of Bessel’s function and those of Kotsuzumi may indicate harmonic properties. Then the Ootsuzumi and Kotsuzumi tones are analyzed and their various physical parameters are extracted by means of discrete Fourier transform (DFT) techniques, and the synthesized tones using these parameters are produced and studied with regard to the features of these parameters contributing to the tone quality of Tsuzumi. Physical parameters for several playing styles of each Tsuzumi are classified in the following: (1) waveforms, (2) spectra, (3) amplitude envelopes of partials, and (4) time variances of the frequencies of partials. Finally, a subjective test for the above synthesized tones with the original ones is performed. It is verified that the synthesized tones have good similarity with the original ones using the following methods: (a) partial synthesis for Ootsuzumi tones, (b) additive synthesis for Kotsuzumi tones on Otsu and Hodo styles, and (c) additive synthesis which includes partial synthesis on the parts of the spectrum for Kotsuzumi tones on Kashira and Kan styles.