Vibration modes and sound characteristic analysis for different sizes of singing bowls

¹ Department of Mechanical Engineering, National Pingtung University of Science and Technology, Pingtung, 912, Taiwan
² Machinery Division, National Nei-Pu Senior Agricultural Industrial Vocational School, Pingtung, 912, Taiwan

^* Corresponding author : wangbt@mail.npust.edu.tw

Abstract

The singing bowl is used not only for the instrument of Buddhism but also for musical therapy. This work aims to investigate the correlation of vibration modes and percussion sound for singing bowls. A typical singing bowl is first selected to perform finite element analysis (FEA) for theoretical modal analysis (TMA) as well as experimental modal analysis (EMA). Modal parameters of singing bowl, including natural frequencies and mode shapes, can be obtained from analysis and experiment, respectively. Singing bowl FE model can then be updated and verified by adjusting material properties and used to predict structural vibration modes. The percussion sound of singing bowl is also measured to obtain its sound spectrum. The peak frequency response of singing bowl sound can be interpreted and contributed from circular vibration modes of the bowl. With the knowledge of sound generation mechanism for the singing bowl, this work also studies the percussion sound characteristics of seven different sizes of singing bowls. Results show the fundamental frequency and overtone frequencies of singing bowl percussion sound are higher for the smaller size. Interestingly, that the peak resonant frequencies have near the integer ratio relationship makes the singing bowl revealing harmony sound effects. The radiated sound spectrum can be well calibrated and predicted for different sizes of singing bowls. This work shows the analytical and experimental approaches in studying the singing bowl percussion sound that strongly correlated to structural vibration modes and can be adopted for future development of singing bowls.