to transmit the audio signal from the microphone pick up to the tooth referring now to fig7 of the accompanying drawings a microphone transmitter 70 is typically worn or carried by the subject and includes a microphone responsive to ambient sound to provide a corresponding electrical signal a transmitter housed in unit 70 transmits a signal at a predetermined radio carrier frequency the radio signal being modulated by the audio signal sensed by the microphone the receiver located in the subject 39 s mouth such as in housing 40 of fig4 or in a retainer or denture 53 of the type illustrated in fig5 is tuned to the predetermined radio carrier frequency transmitted by microphone transmitter 70 and in a conventional manner demodulates the received signal to recover the original audio signal derived by the microphone the level of the audio signal may be varied by a potentiometer 73 that is also located in the housing and preset at the time housing 40 is molded about the receiver components the level adjusted audio signal is then applied to the male connector 30 the female connector 25 and ultimately to transducer 15 implanted in the subject 39 s tooth the required power supply not shown for the receiver demodulator 71 is also contained within housing 40 referring to fig8 of the accompanying drawings the embodiment described in relation to fig5 and 6 includes a microphone 80 typically worn or carried by the subject the audio signal provided by microphone 80 in response to ambient sound is applied across a primary coil 81 that is also worn or carried by the subject typically as with prior art ear mounted hearing aid systems using.