Implementation of implantable microphone in the middle ear cavity and telemetry module

With the advent of implantable hearing aids, acoustic sensing strategy of the implantable microphone becomes an important issue. In this paper, placing the microphone in middle ear cavity (MEC) is proposed and researched feedback characteristic when both the implantable microphone and transducer were in the MEC. Analytical and finite element analysis were conducted and implemented the microphone to have a natural frequency of 7 kHz. The implemented microphone showed good characteristics of SNR, sensitivity, and vibration immunity. For the verification, small animal in vitro experiments (n=4) conducted. From the experiments, the gain margin was measured and showed feasibility to use.