Real-time audio detection and regeneration of moving sound source based on optical flow algorithm of laser speckle images.

Sound detection with optical means is an appealing research topic. In this manuscript, we proposed a laser microphone system allowing simultaneous detection and regeneration of the audio signal by observing the movement of secondary speckle patterns. In the proposed system, optical flow method, along with some denoising algorithms are employed to obtain the motion information of the speckle sequence with high speed. Owing to this, audio signal can be regenerated in real time with simple optical setup even the sound source is moving. Experiments have been conducted and the results show that the proposed system can restore high quality audio signal in real time under various conditions.