Coherence-Based Dual-Channel Noise Reduction Algorithm in a Complex Noisy Environment

In this paper, a coherence-based noise reduction algorithm is proposed for a dual-channel speech enhancement system operating in a complex noise environment. The spatial coherence between two omnidirectional microphones is one of the crucial information for the dual-channel speech enhancement system. In this paper, we introduce a new model of coherence function for the complex noise environment in which a target speech coexists with a coherent interference and diffuse noise around. From the coherence model, three numerical methods of computing the normalized signal to interference plus diffuse noise ratio (SINR), which is related to the Wiener filter gain, are derived. Objective parameters measured from the enhanced speech demonstrate superior performance of the proposed algorithm in terms of speech quality and intelligibility, over the conventional coherence-based noise reduction algorithm.