Abstract: A novel dual-microphone speech enhancement technique is proposed that utilizes the coherence function between input signals as a criterion for noise reduction. The technique is based on certain assumptions regarding the spatial properties of the target and noise signals and can be applied to arrays with closely spaced microphones, where noise captured by sensors is highly correlated (e.g., inside a mildly reverberant environment). The proposed algorithm is simple to implement and requires no estimation of noise statistics. In addition, it offers the advantage of coping with situations in which multiple interfering sources located at different azimuths might be present.