A real-time 3D sound localization system with miniature microphone array for virtual reality

This paper presents a real-time three-dimensional (3D) wideband sound localization system designed with a miniature XYZO microphone array. Unlike the conventional microphone arrays for sound localization using only omnidirectional microphones, the presented microphone array is designed with both bidirectional (pressure gradient) and omnidirectional microphones. Therefore, the array has significantly reduced size and is known as the world´s smallest microphone array design for 3D sound source localization in air. In this paper, we describe the 3D array configuration and perform array calibration. For 3D sound localization, we provide studies on the array output model of the XYZO array, the widely known direction-of-arrival (DOA) estimation methods and the direction search in 3D space. To achieve the real-time processing for 1° search resolution, we accelerate the parallel computations on GPU platform with CUDA programming, and a 130X speedup is achieved compared to a multi-thread CPU implementation. The performance of the proposed system is studied under various reverberation lengths and signal-to-noise levels. We also demonstrate a real-time 3D sound localization demo showing good ability to virtual reality.