Abstract: A hearing aid is set forth that includes one or more hearing aid components that introduce an undesired undamped peak into the frequency response of the hearing aid. An electronic damping filter is utilized to compensate for the undamped peak. The electronic damping filter has a notch filter response that includes an inverse peak across the frequency range of the undamped peak thereby electronically damping the frequency response so that the hearing aid output is generally unaffected by the undesired characteristics of the inverse peak. The electronic damping filter may be programmable to vary the magnitude and/or shift the frequency of the inverse peak. A method is set forth that exploits this programmability and allows the same circuit topology to be used in two different hearing aids respectively having two different undamped peaks. A further method allows handling two or more peaks.

Abstract: A rectifier circuit produces an output which is a function of the magnitude of an input signal and has a controllable transient response. The circuit requires no rectification diodes. The voltage on a capacitor is sensed and compared with that of an input voltage. The operation of charging and discharging switches is adjusted by a control circuit to charge the capacitor if the magnitude of the input signal is greater than the capacitor voltage and to discharge the capacitor if the magnitude of the input signal is less than the capacitor voltage. The attack and release function of the rectifier is selectable by limiting the rate at which current charges/discharges the capacitor, preferably with constant current sources comprised of current mirrors. Multiple time constants are achieved by replicating the storage capacitor and charge/discharge elements configured with different time constants and then summing the resultant capacitor voltages.

Abstract: A hearing aid is set forth that includes one or more hearing aid components that introduce an undesired undamped peak into the frequency response of the hearing aid. An electronic damping filter is utilized to compensate for the undamped peak. The electronic damping filter has a notch filter response that includes an inverse peak across the frequency range of the undamped peak thereby electronically damping the frequency response so that the hearing aid output is generally unaffected by the undesired characteristics of the inverse peak.The electronic damping filter may be programmable to vary the magnitude and/or shift the frequency of the inverse peak. A method is set forth that exploits this programmability and allows the same circuit topology to be used in two different hearing aids respectively having two different undamped peaks. A further method allows handling two or more peaks.

Abstract: A hearing aid is set forth that includes one or more hearing aid components that introduce an undesired undamped peak into the frequency response of the hearing aid. An electronic damping filter is utilized to compensate for the undamped peak. The electronic damping filter has a notch filter response that includes an inverse peak across the frequency range of the undamped peak thereby electronically damping the frequency response so that the hearing aid output is generally unaffected by the undesired characteristics of the inverse peak. The electronic damping filter may be programmed to vary the magnitude and/or shift the frequency of the inverse peak. A method is set forth that exploits this programmability and allows the same circuit topology to be used in two different hearing aids respectively having two different undamped peaks. A further method allows handling two or more peaks.

Abstract: A method and apparatus for discriminating the data signal of a transmitter means. Binary encoded data is transmitted between a transmitter means and a receiver means in an amplitude modulated signal varying about a threshold level. A means and method are included for determining the number of threshold crossings of the carrier during each of a number of discrete successive time intervals. A further method and means characterizes those of said time intervals wherein the number of threshold crossings equals or exceeds a first predetermined number as a mark, and those of said time intervals wherein the number of threshold crossings does not exceed said predetermined number as a null. The number of successive marks not separated by a predetermined number of nulls is then counted by a further aspect of the method and means.