Extracting Reverberant Sound Using a Linearly Constrained Minimum Variance Spatial Filter

Microphone arrays are typically used to extract the direct sound of sound sources while suppressing noise and reverberation. Applications such as immersive spatial sound reproduction commonly also require an estimate of the reverberant sound. A linearly constrained minimum variance filter, of which one of the constraints is related to the spatial coherence of the assumed reverberant sound field, is proposed to obtain an estimate of the sound pressure of the reverberant field. The proposed spatial filter provides an almost omnidirectional directivity pattern with spatial nulls for the directions-of-arrival of the direct sound. The filter is computationally efficient and outperforms existing methods.