Diffuseness estimation with high temporal resolution via spatial coherence between virtual first-order microphones

The diffuseness of sound can be estimated with practical microphone setups by considering the spatial coherence between two microphone signals. In applications where small arrays of omnidirectional microphones are preferred, the diffuseness estimation is impaired by a high signal coherence in diffuse fields at lower frequencies, which is particularly problematic when carrying out the estimation with high temporal resolution. Therefore, we propose to exploit the spatial coherence between two virtual first-order microphones derived from the omnidirectional array. This represents a flexible method to accurately estimate the diffuseness in high-SNR regions at lower frequencies with high temporal resolution.