Characterization of diffusivity based on spherical array processing

The purpose of this study is to assess the diffuse field conditions in a reverberant space using a sound field reconstruction method based on spherical microphone array measurements. Spherical microphone arrays are particularly well suited for applications in non-anechoic enclosures, where the sound waves impinge on the array from multiple directions, as they have convenient properties such as omnidirectionality and compensable scattering from the rigid sphere. The proposed methodology makes use of a spherical equivalent source method (S-ESM) to reconstruct the sound field over a three-dimensional domain and consequently examine some of its fundamental properties: spatial distribution of sound pressure levels, particle velocity and sound intensity. The study allows for visualization of the intensity field inside a reverberant space, and successfully illustrates the behavior of the sound field in such an environment. This initial investigation shows the validity of the suggested processing and reveals interesting perspectives for future work. Ultimately, the aim is to define a proper and reliable measure of the diffuse sound field conditions in a reverberation chamber, with the prospect of improving the accuracy of sound absorption, sound power, and transmission loss measurements.