A High-Speed Camera-Based Approach to Massive Sound Sensing With Optical Wireless Acoustic Sensors

This paper introduces an optical wireless audio system, which takes advantage of the parallel transmission feature offered by the arrangement of LEDs and a high-speed video camera. The motivation for building such system is the limitation encountered when deploying huge arrays of sound sensors, as existent wired and RF wireless microphones are undermined by complexity, energy, and bandwidth issues. In contrast, the proposed prototype is able to simultaneously capture 120 audio channels with full bandwidth each. Although the scalability to more channels is currently constrained by the camera interface hardware, our numerical analysis suggests that the proposed algorithms can decode optical signals of over 12 500 audio channels in a single GPU card. We discuss the various challenges involved in its deployment from the optical, image, and audio signal processing standpoints, and develop theoretical and practical solutions to accomplish a full real-time system integration. We further present examples of typical applications such as acoustic imaging of sound fields by beamforming with microphone arrays.