Abstract: An implanted hearing aid for deaf patient having an intact auditory nerve includes an implanted receiver unit provided with a receiver coil surrounding patient's auditory channel. An external transmitter unit is electrically connected to a separate transmitter coil embedded in a fitting piece insertable into the auditory channel in the range of the receiving coil so as to establish an optimum inductive coupling. A microphone is supported on an ear yoke and connected both to the transmitter and the receiver units. The receiver unit is electrically connected to an excitation electrode mounted on cochlea in patient's ear.

Abstract: A multi-frequency transmission system for implanted hearing aid includes an external transmitting part and an encapsuled receiver part implantable into middle ear of the user. The transmitting part includes a microphone, a speech processor including a set of audio frequency band pass filters connected respectively via adjustable threshold switches to pulse shapers which release an audio frequency band only when an adjusted threshold level is exceeded. A plurality of high frequency transmitters is modulated by the signals from the pulse shapers. A pair of additional high frequency transmitters is controlled by the pulses from the speech processor to alternately transmit high frequency pulses corresponding to the polarity of the triggering pulses. A frequency channel selector is connected between the transmitters and the speech processor to activate simultaneously one of the transmitters from the bipolar high frequency stage and one of the amplitude modulated transmitters.