Room acoustics simulation for multichannel microphone arrays

Abstract

A new and efficient room acoustics simulation software package forMATLAB is presented which can simulate recordings of arbitrary microphone arrays within an echoic room. This simulator supports research related to developing and experimenting with multichannel microphone arrays and higher order ambisonic playback. Based upon the work by Schimmel et al. [1], this new simulation software package models both specular and diffuse reflections in a shoebox type environment. It is an improvement over previous work as it can simulate microphone arrays with arbitrary directional impulse responses and large numbers of sensors. The spherical harmonic expansion up to a specified order at any point within an echoic room can also be simulated by specifying a microphone array with custom directional gains that match the spherical harmonic functions. Furthermore, this simulator provides realistic phase information for the sound recorded by the microphone array, including accurate inter-sensor time delays for the sources and early specular reflections. The room acoustics simulator is implemented as a C program that interfaces with MATLAB and is freely available from the authors.