A cochlear prosthesis composed of a transmitter part which is to be carried exterior to the user's body and a receiver part which is to be implanted in the user, the transmitter and receiver parts being coupled by a radio link provided by implanted receiver coils and external transmitter coils free of...http://www.google.com.au/patents/US5069210?utm_source=gb-gplus-sharePatent US5069210 - Cochlear implant employing frequency-division multiplexing and frequency modulation
