Blind estimation of the coherent-to-diffuse energy ratio from noisy speech signals

A novel dual-channel algorithm is proposed which estimates the coherent-to-diffuse energy ratio (CDR) of background noise in mixed noise fields. The algorithm is based on an estimate of the noise field coherence from a noisy speech signal and a subsequent minima tracking in order to increase the estimation accuracy even in the presence of speech. The obtained CDR estimate can be used, e.g., for the acoustic environment classification in hearing aids or to control speech enhancement algorithms such as noise reduction or speech dereverberation. Besides, the approach can be used to calculate an estimate of the direct-to-reverberant energy ratio (DRR) blindly from reverberant speech signals.