An implantable microphone device is provided. The device comprises a hermetically sealed housing (3) having an internal cavity (2). The internal cavity (2) has a microphone assembly arranged to receive sound waves originating from external the housing (3). The device further comprises a pressure sensor arrangement, arranged to detect and determine the differential pressure between the internal cavity (2) and the exterior of the housing (3). The determined differential pressure is used to determine a suitable transfer function to be applied to the output of the microphone assembly to produce a signal representative of the received sound waves.
