Simultaneous detection and analysis of reed vibration and sound of sheng pipes

Framed by a common research program of Chinese Academy of Sciences and of the Fraunhofer Gesellschaft a cooperation project on the acoustics of Chinese and European wind instruments has been established. A first set of experiments is dedicated to reed vibration and sound of individual pipes of a sheng, a typical Chinese free-reed instrument. The investigated pipe of the sheng was mounted in a tailored transparent boot, which allowed the measurement of the velocity of reed vibration by using a laser vibrometer. Simultaneously, the sound of the pipe was detected by a microphone located in the near field of the sound source. The pressurized air for exciting the sheng pipe was provided by a bidirectional laboratory wind system, developed originally for driving organ pipes. Both the reed velocity and sound pressure signals were synchronously sampled by a four channel AD board and recorded by a laptop. The measurements were carried out in a semi-anechoic chamber. Reed velocity and sound pressure as functions of wind pressure and air consumption were studied experimentally. Spectra of reed velocity and sound pressure were calculated from the recorded signals by a special sound analysis software. The attack transients which are very important for the perceived sound of the instrument, were also analyzed. The results presented in this paper will provide a better understanding of the sound generation mechanism of sheng pipes and can be applied for support further research activities with directly applicable potentials.