In the method according to the invention a signal processing unit receives signals from at least two microphones worn on the user's head, which are processed so as to distinguish as well as possible between the sound from the user's mouth and sounds originating from other sources. The distinction is based on the specific characteristics of the sound field produced by own voice, e.g. near-field effects (proximity, reactive intensity) or the symmetry of the mouth with respect to the user's head.