Abstract: Apparatus for use as an in-the-ear hearing aid. The apparatus includes a housing having a shell and a face plate, wherein the shell is molded to custom fit a hearing aid wearer's ear. A first non-directional microphone system is included having a first output signal representative of the sound received. A second non-directional microphone system is included having a second output signal representative of the sound received. A switch mechanism is included having an operator extending through the housing for switching the in-the-ear hearing aid between a non-directional mode and a directional mode. In the directional mode, the microphone system is adjustable to account for component tolerances. The switched directional/non directional microphone feature is employed in a custom in-the-ear Contralateral Routing of Signals (CROS) or Bilateral Routing of Signals (BiCROS) two instrument hearing aid system.

Abstract: An acoustic conditioning apparatus. The mechanism includes an attenuator to limit excessive noise levels. The attenuator includes a circuit for compressing an output sound pressure level below a desired level, such as 90 dBA over an eight-hour period. The mechanism also includes an amplifier for conditioning ambient sound level in accordance with the normal needs of a hearing impaired person using the conditioning apparatus. Additionally included is a switch in an electrical circuit to enable selection of attenuation of excessive noise levels or normal amplification. The switch can be controlled either manually by means of a toggle on a housing enclosing the various components, or automatically in response to the sensed noise level.