Abstract: An apparatus for controlling an adjustable operational parameter of a hearing aid by the use of an external magnetic actuator held in proximity with the hearing aid. The hearing aid has a microphone for generating signals, hearing aid circuitry for processing the signals, an output transducer for transforming the processed signals to a user compatible form, and a single magnetic switch, such as a reed switch, connected to the hearing aid circuitry. The magnetic switch controls the hearing aid circuitry to adjust an adjustable operational parameter, such as volume. In one embodiment the adjustable operational parameter continues to adjust or cycle between a minimum and a maximum as long as the magnetic actuator is maintained in proximity with the magnetic switch. When the magnetic actuator is removed the adjustment ceases. The invention allows precise adjustment and control of an adjustable parameter with minimal effort and movement by the user.

Abstract: An apparatus and method for controlling a plurality of adjustable operational parameters of a hearing aid by the movement of an external magnetic actuator into and out of proximity with the hearing aid. The hearing aid has a microphone, hearing aid circuitry, an output transducer, and a magnetic switch, such as a reed switch, connected to the hearing aid circuitry. The hearing aid circuitry has a plurality of adjustable operational parameters and includes control processing circuity for switching between and controlling the adjustable operational parameters. The magnetic source is moved into and out of proximity with the hearing aid a selected number of times activating the magnetic switch each time.

Abstract: A hearing aid is programmable with dual-tone multiple-frequency signals, received through the hearing aid microphone, to adjust operating coefficients of signal conditioning circuitry in the aid. A DTMF receiver filters and detects DTMF tone pairs into digital words provided to a controller for decoding, some of the digital words representing programming instructions and others representing data. In accordance with the instructions, the controller conveys the data to memory operatively associated with a plurality of control ports to the signal conditioning circuitry, with operating coefficients of the conditioning circuitry determined by the contents of the memory.

Abstract: A volume control circuit for hearing aids is adjustable to vary a control signal supplied to an amplifier between a microphone and receiver of a hearing air. The volume control circuit includes a positive voltage source, a charge holding circuit, and a switch for alternatively connecting the holding circuit with the positive voltage source to increase its voltage, with ground to decrease voltage, and with an open circuit to maintain a constant voltage. The holding circuit voltage is inverted around a predetermined reference voltage level, with the inverted signal amplified and applied to the gate terminal of an n-channel field effect transistor having its source terminal biased to a predetermined source voltage level, and its drain terminal electrically connected to the amplifier to provide the control signal. In response to charging of the holding circuit, the gate voltage is reduced to increase the FET impedance, thus decreasing the gain of the amplifier.

Abstract: A signal processing circuit for hearing aids includes a broadband peak detector for generating a control voltage based upon the sound pressure level of an incoming acoustical signal over its entire frequency spectrum. The control signal is used to determine the cut-off frequency of a voltage controlled adaptive high-pass filter. An amplified electrical signal, corresponding to the acoustical signal, also is provided to the high-pass filter. In setting the cut-off frequency, the control voltage causes the high-pass filter to selectively suppress the low frequency portion of the signal, generating a modified signal in which the noise component is reduced.