The design of a small (0.8×0.5×0.2 in.) and light (1g) noise‐cancelling microphone based on the electret transducer is described. The microphone, mounted at the end of a boom, is used for a new operator's headset. The basic electret transducer is used as a first‐order gradient microphone whose directional characteristic is adjusted so that, for a given bandwidth and background noise spectrum (speech from nearby operators), the noise‐cancelling property is optimized. Pratical results indicating a minimum of 8 dB noise rejection are presented.