Abstract: A method for forming a standardized faceplate for an individually adapted in-the-ear hearing aid shell which matches the physical characteristics of the hearing aid user's ear, and for fabricating an individually-adapted in-the-ear hearing aid shell made of radiation-reactive material and a battery compartment therein.

Abstract: A method for fabricating an individually adapted in-the-ear hearing aid shell with a battery compartment cast into the shell such that the door of the battery compartment is flush or slightly recessed in the portion of the shell that contacts the user's ear cavity.

Abstract: The specification discloses a trans-tympanic rod having a magnet at one end, and connected at the opposite end to a location in the middle ear, for transmitting the vibrations induced in the magnet by a magnetic induction hearing aid, to the inner ear. The rod can mate with the malleus by way of a set of prongs or by insertion in a hole in the malleus. Alternately, the rod can mate with a hole in an ossicular replacement prosthesis. Additionally, the rod can mate with a horseshoe shaped prosthesis located between the tympanic membrane and the malleus.

Abstract: A prosthesis for use with an intact ossicular chain to allow a magnet to be coupled to the ossicular chain, the magnet being moved by an electromagnetic induction hearing aid. The prosthesis has a body having a first groove which cooperates with the manubrium and a second groove formed by an arm extending from the body and a hooked end, the second groove cooperating with the long process. A magnet is connected to a planar surface developed by the arm and the hooked end and is generally parallel to the tympanic membrane when installed. A conventional disk shaped magnet can be utilized inside a biocompatible housing.

Abstract: A magnet assembly for location around portions of bones in the middle ear where one portion of the assembly is a magnet and another portion of the assembly is a magnetic material, the portions being hinged to one another so that they are held around the bone by the magnetic field and being adapted for optimal coupling with a magnetic field produced by a coil in a magnetic induction hearing aid.

Abstract: A noise elimination circuit, especially for a hearing aid, which removes all sound below a predetermined level and transmits a compressed sound range for all sounds above a predetermined level. The circuit uses a field effect transistor as a voltage variable resistor to transmit a signal when the sound signal is being compressed or is over a predetermined level and block the signal when the sound signal is not being compressed or is below the predetermined level. The field effect transistor drain to source resistance is varied by transmitting a signal indicative of the compression or signal level to the gate of the transistor, such that the gate voltage is higher than the source voltage when signal transfer is desired and the gate voltage is less than the source voltage when no signal transfer is desired. A switch is provided to defeat the noise elimination circuitry.

Abstract: A touch sensitive electronic volume control circuit so that the gain of an amplifier can be changed to any level from zero to maximum and the gain can be retained for periods of time without user adjustment or for power supply replacement.