Microphone arrangement for a breathing mask

An apparatus comprising a breathing mask and an electro-acoustical transducer device engaged to the breathing mask, the electro-acoustical transducer device comprising:

• a body structure, and
• a differential microphone located in an aperture of a first wall of the body structure,
• wherein
• the differential microphone comprises a front side for receiving an acoustical signal and a rear side for receiving the acoustical signal in modified form,
• the differential microphone is arranged to produce an electrical output signal substantially proportional to a difference of the acoustical signal at the front side and the acoustical signal at the rear side,
• the body structure is arranged to form a chamber shared with the rear side of the differential microphone, and
• there is at least one first tubular channel in the first wall of the body structure to the chamber so that the at least one first tubular channel and the chamber constitute an acoustical filter for filtering the acoustical signal falling to the rear side of the differential microphone.