Sound field synthesis method using distributed spherical microphone arrays based on spherical harmonics

Sound field synthesis is one of the core techniques for realizing advanced virtual reality systems. The development of micro-electromechanical systems technology has enabled the use of compact spherical microphone arrays (SMAs) with numerous microphones to capture accurate sound field. While an SMA typically needs to be placed at the listening point, this placement is not always feasible in real-world scenarios. To address this issue, several methods have been proposed to reproduce sound field using distributed SMAs, without requiring them to be positioned at the listening point. One conventional technique involves translating the spherical harmonic (SH) center to the listening point by converting the expansion coefficients obtained from each SMA. However, the accuracy of the reconstructed sound field is often insufficient. In this presentation, we introduce our proposed sound field synthesis methods using distributed SMAs. In the methods, secondary sound pressures are calculated from the signals recorded by the SMAs. The sound pressure at the listening point is then reconstructed from these secondary sound pressures using SH-based approaches, such as the Auditory Display based on Virtual Sphere (ADVISE) model. The simulation results indicate that the proposed methods can synthesize sound field even when the listening point is far from SMAs.