Empirical analysis of modal precession in crystalline Himalayan singing bowls

To date, there is little data on the modal precession and acoustic beating effect observed when utilizing crystalline structure Himalayan singing bowls. This study will present data found through multiple experiments, including the use of a multipoint scanning laser Doppler vibrometer, performed on several crystalline bowls. The results from various experiments support the hypothesis that the acoustic beating effect often perceived from Himalayan bowls of any structural type is due to the rotation of the fundamental mode around the circumference of the bowl, and not an interference effect cause by the modulation of multiple frequencies present. In addition, the highly symetric geometry of the crystalline bowls produces very small spread in the bandwidth of frequencies present, including a lack of harmonic content beyond the fundamental frequency, when the crystalline bowl is excited.