A Practical Approach for Microphone Array Calibration in Augmented and Virtual Reality Applications

Abstract

Spatial sound is rapidly becoming an important part of augmented reality (AR) and virtual reality (VR) applications. Microphone calibration is essential for providing spatial sound capture and reproduction capabilities in AR/VR. This paper presents RAndom PerturbatIons for Diffuse-field (RAPID), a precise method for the diffuse field calibration of the magnitude responses of microphones. The performance of RAPID is compared against the ground truth obtained using a well-established method utilising a two-axis turntable. Notably, it is possible to perform calibration using RAPID in 30 seconds, whereas calibration using the turntable method can take up to 4 hours. RAPID achieves similar results to the ground truth with significantly less effort and setup requirements. A tool is also available as an open source MATLAB application for performing RAPID calibration with ±0.5 dB accuracy.