Room acoustics measurements by microphone arrays

Room acoustics measurements play an important role in the design and analysis of enclosures for music and speech. Spatial measures such as the directivity index use spatial sound field information and attempt to predict the performance of enclosures for speech and music. Although recently developed microphone arrays were suggested for the measurement of these measures, they do not have sufficient spatial resolution to perform a complete, detailed analysis of sound fields. In this paper, the decomposition of acoustic fields into plane waves is performed by spherical microphone arrays, which use a large number of samples over a sphere to achieve high spatial resolution. The array processing then employs the spherical Fourier transform for the decomposition into plane waves. The paper presents simulation results of spherical array processing in various sound fields and examines the requirements for successful application of the method in realistic sound fields.