Optical microphone array

Visualization of propagating sound wave by optical technique

Visualization of propagation of sound wave is useful for reduction of sound nose, detection of the abnormal sound in machine, and medical tools as ultrasound wave. In common way, a microphone is used, but it is difficult to visualize the propagation behavior of the sound wave. We have proposed a method of visualizing the sound wave propagation and reproduce the sound wave by using digital holography.