Implantable microphone for hearing systems

An implantable microphone for use in hearing systems comprising:

• a housing having a sidewall and a back wall adjacent to the sidewall, the back wall having a recess configured to be coupled to an auditory ossicle;
• a first membrane coupled to a top portion of the housing, the first membrane configured to move in response to movement from the auditory ossicle;
• a second membrane coupled to the sidewall and configured to move in response to movement from the first membrane, the second membrane dividing an interior volume of the housing into a first volume and a second volume such that the first volume is on one side of the second membrane and the second volume is on the other side of the second membrane, the first volume having an opening that permits fluid to flow out from the first volume, the second membrane configured to move in response to movement from the fluid;
• and
• a vibration sensor coupled to the second membrane, the vibration sensor configured to measure the movement of the second membrane and convert the measurement into an electrical signal, wherein the vibration sensor is a MEMS differential capacitor.