Central Institute for the Deaf

Storz Instrument Co.

K/s Himpp

A Maynard Engebretson

Michael P O'Connell

Robert E Morley, Jr

Thomas J Sullivan

George L Engel

John Fredrickson

Baohua Zheng

Gerald R Popelka

Adaptive compressive gain and level dependent spectral shaping circuitry for a hearing aid include a microphone to produce an input signal and a plurality of channels connected to a common circuit output. Each channel has a preset frequency response. Each channel includes a filter with a preset frequency response to receive the input signal and to produce a filtered signal, a channel amplifier to amplify the filtered signal to produce a channel output signal, a threshold register to establish a channel threshold level, and a gain circuit. The gain circuit increases the gain of the channel amplifier when the channel output signal falls below the channel threshold level and decreases the gain of the channel amplifier when the channel output signal rises above the channel threshold level. A transducer produces sound in response to the signal passed by the common circuit output.

Adaptive gain and filtering circuit for a sound reproduction system

An electronic filter for an electroacoustic system. The system has a microphone for generating an electrical output from external sounds and an electrically driven transducer for emitting sound. Some of the sound emitted by the transducer returns to the microphone means to add a feedback contribution to its electrical output. The electronic filter includes a first circuit for electronic processing of the electrical output of the microphone to produce a first signal. An adaptive filter, interconnected with the first circuit, performs electronic processing of the first signal to produce an adaptive output to the first circuit to substantially offset the feedback contribution in the electrical output of the microphone, and the adaptive filter includes means for adapting only in response to polarities of signals supplied to and from the first circuit. Other electronic filters for hearing aids, public address systems and other electroacoustic systems, as well as such systems and methods of operating them are also disclosed.

Electronic filters, hearing aids and methods

A noise reduction circuit for a hearing aid having an adaptive filter for producing a signal which estimates the noise components present in an input signal. The circuit includes a second filter for receiving the noise-estimating signal and modifying it as a function of a user's preference or as a function of an expected noise environment. The circuit also includes a gain control for adjusting the magnitude of the modified noise-estimating signal, thereby allowing for the adjustment of the magnitude of the circuit response. The circuit also includes a signal combiner for combining the input signal with the adjusted noise-estimating signal to produce a noise reduced output signal.

Adaptive noise reduction circuit for a sound reproduction system

An electronic filter for filtering an electrical signal. Signal processing circuitry therein includes a logarithmic filter having a series of filter stages with inputs and outputs in cascade and respective circuits associated with the filter stages for storing electrical representations of filter parameters. The filter stages include circuits for respectively adding the electrical representations of the filter parameters to the electrical signal to be filtered thereby producing a set of filter sum signals. At least one of the filter stages includes circuitry for producing a filter signal in substantially logarithmic form at its output by combining a filter sum signal for that filter stage with a signal from an output of another filter stage. The signal processing circuitry produces an intermediate output signal, and a multiplexer connected to the signal processing circuit multiplexes the intermediate output signal with the electrical signal to be filtered so that the logarithmic filter operates as both a logarithmic prefilter and a logarithmic postfilter. Other electronic filters, signal conversion apparatus, electroacoustic systems, hearing aids and methods are also disclosed.

Electronic filters, signal conversion apparatus, hearing aids and methods

Electronic filters, repeated signal charge conversion apparatus, hearing

An electronic filter for filtering an electrical signal. Signal processing circuitry therein includes a logarithmic filter having a series of filter stages with inputs and outputs in cascade and respective circuits as

The acoustical coupler has a closed-bottom containment with compliant diaphragm attached to the containment periphery to form an acoustic chamber. A length of tubing is connected through the side or bottom or the containment of the chamber for conveying sound pressure between the chamber and an electroacoustic transducer connected at the other end of the tubing. The transducer may be either a microphone or a hearing aid receiver. The electroacoustic transducer, being too large for direct placement within the middle ear cavity may be located elsewhere in the skull, such as behind the ear adjacent to the surface of the skin. When connected to a microphone, the coupler may be placed within the middle ear cavity behind the tympanic membrane and may be attached to the malleus with a wire hook secured to the coupler diaphragm. When attached to a vibration sending unit the coupler may transfer the generated vibration directly to the incus end of the stapes. In one embodiment, this transfer is effected by means of a hollow tube having a generally hollow member therein and containing a quantity of low loss material. The member defines one end connected to the vibration sending unit and a second end connected directly to the stapes.

Implantable hearing aid coupler device

The implanted device includes a rectifier circuit which is switched between modes of half wave and full wave rectification in response to the signal to be conveyed. The external device is inductively coupled to the implanted device through a pair of coils, one coil being embedded beneath the skin, forming the primary and secondary windings of a transformer. The external device delivers energy to the implanted device in amounts which vary in accordance with the rectification mode of the implanted device. By monitoring the energy delivered, the external device determines the rectification modes as they are switched and thereby ascertains the signal being conveyed from the implanted device.

Method of readout of implanted hearing aid device and apparatus therefor

An electronic filter for an electroacoustic system. The system has a microphone for generating an electrical output from external sounds and an electrically driven transducer for emitting sound. Some of the sound emitted by the transducer returns to the microphone means to add a feedback contribution to its electical output. The electronic filter includes a first circuit for electronic processing of the electrical output of the microphone to produce a filtered signal. An adaptive filter, interconnected with the first circuit, performs electronic processing of the filtered signal to produce an adaptive output to the first circuit to substantially offset the feedback contribution in the electrical output of the microphone, and the adaptive filter includes means for adapting only in response to polarities of signals supplied to and from the first circuit. Other electronic filters for hearing aids, public address systems and other electroacoustic systems, as well as such systems, and methods of operating them are also disclosed.

The acoustical coupler has a closed-bottom containment with compliant diaphragm attached to the containment periphery to form an acoustic chamber. A length of tubing is connected through the side or bottom of the containment to the chamber for conveying sound pressure between the chamber and an electroacoustic transducer connected at the other end of the tubing. The transducer may be either a microphone or a hearing aid receiver. The electroacoustic transducer, being too large for direct placement within the middle ear cavity may be located elsewhere in the skull, such as behind the ear adjacent to the surface of the skin. When connected to a microphone the coupler may be placed within the middle ear cavity behind the tympanic membrane and may be attached to the malleus with a wire hook secured to the coupler diaphragm. When attached to a receiver or vibration sending unit the coupler may be attached to the incus end of the stapes using a porous disc secured to the coupler diaphragm, the porosity of the disc permitting tissue growth and infusion whereby the stapes becomes permanently attached to the disc. The acoustic couplers may be used with a wide range of electronic signal processing and amplification circuitry tailored to the particular patient's hearing loss.

Implantable middle ear hearing aid system and acoustic coupler therefor

A hearing aid including a microphone for generating an electrical output from sounds external to a user of the hearing aid, an electrically driven receiver for emitting sound into the ear of the user of the hearing aid, and circuitry for driving the receiver. The circuitry drives the receiver in a self-generating mode activated by a first set of signals supplied externally of the hearing aid to cause the receiver to emit sound having at least one parameter controlled by the first set of externally supplied signals and then drives the receiver in a filtering mode, activated by a second set of signals supplied externally of the hearing aid, with the output of the external microphone filtered according to filter parameters established by the second set of the externally supplied signals. Other forms of the hearing aid, apparatus for supplying the sets of signals to the hearing aid in a total system, and methods of operation are also described.

Growing community of inventors

Ladue, MO, United States of America

A Maynard Engebretson