| Abstract: |
A large Balinese gamelan gong, the gong ageng wadon, is similar to other Indonesian gongs in that it is tonal. A previously undocumented phenomenon is the distinct acoustic beating this gong produces. In this study of the Brigham Young University's gong ageng wadon, acoustical and vibrometry measurements were performed. Scanning laser Doppler vibrometer results show a beat frequency of about 3 Hz is produced near 150 Hz and 160 Hz by closely spaced structural modes. A slightly slower beat frequency (around 2.5 Hz) is also produced at about 120 Hz. The difference in this case is that there is only one structural mode measured near this frequency. The acoustic radiation from this mode beats with a harmonic of the radiation from a lower structural mode, which harmonic is caused by nonlinear structural phenomena. |