Abstract: An electrical hearing aid device has a housing in which an integrated amplifier circuit is located. Also contained in the housing is at least one microphone, a switch, a filter, amplifier and a voltage source. The amplifier circuit also has at least one earphone allocated to the amplifier circuit. A protective device provides protection against high frequency electrical waves wherein the integrated amplifier circuit is protected against access of line bound radio frequency currents by filter elements. The filter elements are provided in electrical terminals of the amplifier circuit and directly at the integrated circuit.

Abstract: A hearing aid apparatus is disclosed that employs both an omnidirectional microphone and at least one directional microphone of at least the first order. The electrical signals output from the directional microphone are supplied to an equalization amplifier which at least partially equalizes the amplitude of the low frequency electrical signal components of the electrical signal with the amplitude of the mid and high frequency electrical signal components of the electrical signals of the directional microphone. A switching circuit accepts the signals output from both the omnidirectional microphone and the directional microphone. The switching circuit connects the signal from the omnidirectional microphone to an input of a hearing aid amplifier when the switching circuit is in a first switching state, and connects the output of the equalization circuit to the hearing aid amplifier input when the switching circuit is in a second switching state.

Abstract: A hearing compensation system for the hearing impaired comprises an input transducer for converting acoustical information at an input to electrical signals at an output, an output transducer for converting electrical signals at an input to acoustical information at an output, a plurality of bandpass filters, each bandpass filter having an input connected to the output of said input transducer, a plurality of AGC circuits, each individual AGC circuit associated with a different one of the bandpass filters and having an input connected to the output of its associated bandpass filter and an output connected to the input of the output transducer. The bandpass filters and AGC circuits may be divided into two processing channels, one for low frequencies and one for high frequencies and may drive separate audio transducers, one configured for maximum efficiency at low frequencies and one configured for maximum efficiency at high frequencies.

Abstract: A hearing aid has input AGC and output AGC using only one attack/release circuit and only one variable gain amplifier. An input AGC signal and an output AGC signal are summed and the summed signal, processed through the attack/release circuit, is used to control the gain of the variable gain amplifier.

Abstract: A method and circuit for signal amplification in digital hearing aids, in particular in hearing aids with automatic gain control (AGC). In the method there first ensues a digitization of an input signal from the signal path of the hearing aid, then a rectification of sampled values of the digitized input signal. Next a determination of gain values is allocated to the sampled values, after which there is a smoothing of the gain values. Finally, after previous allocation of the smoothed gain values to the sampled values, allocated values, reconverted to analog form, are outputted into the signal path of the hearing aid.

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 compensation system comprises an input transducer for converting acoustical information at an input thereof to electrical signals at an output thereof, a differential analog-to-digital converter sampling the electrical signals output from the input transducer at an input thereof and outputting differential signal samples at an output thereof, a digital signal processing circuit having an input connected to the output of the differential analog-to-digital converter and operating on the differential signal samples to form processed differential signal samples at an output thereof, and an output transducer for converting electrical signals at an input thereof to acoustical information at an output thereof, the processed differential signal samples coupled to the input of the output transducer.

Abstract: A programmable hearing aid has functional parts provided in the housing, such as a microphone, an amplifier circuit, an earphone, a current source, and a socket with electrical contacts, into which a plug of an external programming unit can be inserted. In addition, the hearing aid comprises an audio signal processing unit, so that during the programming of the hearing aid the audio signal processing unit can be simultaneously adjusted.

Abstract: A hearing aid has an input transistor, an amplifier and transmission circuit, an output transducer and a calculating unit that realizes fuzzy logic functions. The calculating unit responds to a tap signal taken at the amplifier and transmission circuit and supplies an event signal that is supplied to the amplifier and transmission circuit and influences an output signal emitted thereby. At least the calculating unit is implemented in digital circuit technology. Such a hearing aid can be manufactured with little development and circuit outlay, operates reliably and enables an optimum matching to the specific requirements of the hearing aid user.

Abstract: The process for controlling a programmable or program-controllable hearing aid for in-situ adjustment of said hearing aid to an optimum target gain in one or more frequency bands by establishing the hearing threshold level of the wearer for one or more frequency bands, determining the target input/output response for the detected hearing loss and generating a corresponding parameter set for an ideal input/output response for the detected hearing loss under feedback-free conditions, by setting the control parameter set of a signal processor initially to an input/output response with a gain equal to the maximum target gain, operating the hearing aid in-situ in accordance with said initial input/output response while monitoring said hearing aid for the occurence of any acoustic feedback, and if no noticeable feedback is detected setting said initial parameter set for said input/output response into said hearing aid, and if noticeable acoustic feedback is detected reducing the gain over at least one of said frequ

Abstract: In a method and an amplifier circuit for harmonic distortion suppression in hearing aids with signal-dependent gain control (AGC), a number of decay times of different length are prescribed for the gain control, and a switch is made between the decay times, and the selection of the respective decay time ensues dependent on a status change of the signal to be processed.

Abstract: A hearing aid circuit using an averaging detector and a plurality of time constants to produce a compression control signal to control the gain of a compression amplifier which compresses an input signal when the averaging detector signal exceeds a predetermined threshold. The compression control signal has an attack and release time. The release time of the compression control signal is proportional to the duration of time during which the averaging signal's amplitude exceeds the predetermined threshold level. The release has a variable recovery rate. The recovery rate is relatively fast during an initial portion of the release time and relatively slower during the remaining portion of the release time. The hearing aid circuit may also use a volume control to adjust the gain of the signal produced by the compression amplifier without adjusting the gain of the signal produced by a linear amplifier to provide volume control for soft sounds independent of loud sounds.

Abstract: A method for sound control of audio signals within a defined frequency range in which the gain of the audio signals is varied using a control element and the filter quality factor and/or the mid-frequency of the audio signals are varied simultaneously by the same control element used to control the gain.

Abstract: A hearing aid uses multiple compression feedback loops to minimize sound distortion includes a preamplifier network having an input connected to an input receiver, an output, and an automatically adjustable gain. The preamplifier network measures an output signal which is preferably a voltage and automatically adjusts the gain in response to the output signal. The hearing aid also includes an output drive network having an input connected to the preamplifier network output and an output connected to a load, such as a transducer. The output drive network has an automatically adjustable gain which is responsive to a measured signal at the output of the network. A volume control circuit may also be connected between the output of the preamplifier network and the input of the output drive network to permit the person wearing the hearing aid to adjust the output volume.

Abstract: A hearing compensation system for the hearing impaired comprises an input transducer for converting acoustical information at an input to electrical signals at an output, an output transducer for converting electrical signals at an input to acoustical information at an output, a plurality of bandpass filters, each bandpass filter having an input connected to the output of said input transducer, a plurality of AGC circuits, each individual AGC circuit associated with a different one of the bandpass filters and having an input connected to the output of its associated bandpass filter and an output connected to the input of the output transducer.

Abstract: An improved analog hearing aid is provided which incorporates a current source transconductance amplifier as an input stage. The gain defining bias current of the input stage transconductance amplifier is adjusted upon the application of battery power to the hearing aid to define a low input signal gain, and is then reduced by two gain regulators to define a compression threshold and compression ratio, and to provide a maximum output ceiling. Also provided is a method of trimming the low signal gain of the hearing aid at the time battery power is applied.

Abstract: In a method for processing data, in particular signal data in a programmable digital hearing aid, first a data memory is searched to locate a stored comparison input value corresponding with a current, incoming input data value E which satisfies a comparison condition. Subsequently the data memory is searched for a stored output value allocated in a predetermined manner now-identified to the stored input data value via a characteristic function. Subsequently the determined comparison output value is emitted as an output value, and the procedure is repeated for further incoming input data values. In a circuit for processing data, particularly signal data, in a programmable hearing aid, the incoming input data value is supplied via a data input/output unit of a processor to a comparison element for determining whether there exists a stored input value corresponding to the current input data value by satisfying a comparison condition.

Abstract: In a method for the adaptation of the transmission characteristic of a hearing aid to the hearing aid impairment of a hearing aid wearer using a personal computer having a pointer device such as a mouse, the acoustician selects segments of the graphic presentation of the hearing aid parameters with the mouse, modifies the graphics point-by-point or segment-by-segment by displacement of the mouse and thereby correspondingly co-modifies appertaining, displayable parameters. The hearing aid can be adapted to reach a target characteristic by means of one adaptation procedure, followed if necessary by further analogous fine adaptation procedures.

Abstract: A multi-channel synchronous compander for hearing aids, in which the input signal from an input transducer is directed through a 2:1 front compressor, then through a band splitting filter to divide it into a desired number of frequency bands, then through expander/compressors to provide selected expansion/compression of each frequency band depending on the user's hearing impairment. The outputs of the expander/compressors are summed, amplified and directed to the hearing aid output transducer. The compressor and each expander/compressor are all controlled by control signals derived from the compressed signal level at the output of the front compressor. The use of common control signals for both the front end compression and the expansion removes the need for close matching of temporal performance and improves the output signal fidelity. The front compressor allows the filter capacitors to be reduced in size so that they can be integrated.