A New Dual-Microphone Speech Enhancement Method for Oriented Noises

In this paper, we examine a modified Cross-Talk Resistant Adaptive Noise Canceller (CTRANC) structure that contains a delay unit on the primary channel to solve the causality constraint of conventional CTRANC. This Asymmetric CTRANC (ACTRANC) structure allows flexible alignment of noise source with the sensors array when the speech source is fixed in its position. Inserting delay unit on the primary path releases the placement of the noise sources and consequently, improves the capability of the structure in noise reduction. This can also be interpreted as the releasing causality constraint on the adaptive filters. We have shown that the best delay value in the structure is proportional to the propagation delay between reference and primary microphones (in terms of sample). Objective evaluations and informal listening tests demonstrate superior performance of the proposed method rather than conventional CTRANC.