To reduce interference in monoaural hearing aids from spatially separated sound sources, the information from multiple microphones might be useful in enhancing the signal from a desired source for monaural presentation. The technique of Griffiths and Jim [IEEE Trans. Antennas Propagat. AP‐30, 27–34 (1982)] was used to filter and combine microphone signals ins way that preserves signals arriving from straight ahead of the microphone array while minimizing output power from off‐axis signals. The filters adapt to the interference environment using a variation of the LMS (Widrow) algorithm. Although it adapts slowly (1 s), LMS approaches optimum performance in stationary, anechoic environments, providing a bound on performance in nonstationary, reverberant environments. In three simulated rooms, anechoic, living room, and conference room, with interferring babble 45° off‐axis and on‐axis target at − 12 dB/S/B, a two‐microphone system with 100‐point filters reduced the interference by 20, 12, and 4 dB, respectively. Informal listening indicated minimal degradation of the desired signal and substantial intelligibility improvement in anechoic and living room environments. [Work supported by NIH.]