Observation of traveling wave with laser tomography

Abstract

In this study, we observe traveling sound waves with a laser and computed tomography. In our previous research, we observed steady-state sound fields using a sine wave signal. However, transient sound fields observation is necessary in order to observe more complicated sound fields that need to be separated into direct and reflected sounds. Therefore, in this study, we use a traveling sound wave (pulse sound wave). For fundamental experiments, we observed projections of a traveling pulse sound wave generated by a 2-way loudspeaker and a flat-panel loudspeaker with a laser. For transit sound fields, we used the sound field projections obtained with a laser to observe that a flat sound wave generated by a flat-panel loudspeaker is reflected by a sound-reflecting board. Then, we reconstructed the sound field information on the transition of a pulse sound wave generated by a 2-way loudspeaker, by computed tomography.