Michael Keith O'Connell

US Patent:

54127351, May 2, 1995

Filed:

Feb 27, 1992

Appl. No.:

7/842566

Inventors:

A. Maynard Engebretson - Ladue MO
Michael P. O'Connell - Somerville MA

Assignee:

Central Institute for the Deaf - St. Louis MO

International Classification:

H04B 1500

US Classification:

381 94

Abstract:

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.

US Patent:

57063524, Jan 6, 1998

Filed:

Apr 7, 1993

Appl. No.:

8/044246

Inventors:

A. Maynard Engebretson - Ladue MO
Michael P. O'Connell - Somerville MA

Assignee:

K/S HIMPP - Vaerloese

International Classification:

H04R 2500

US Classification:

381684

Abstract:

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.

US Patent:

57244332, Mar 3, 1998

Filed:

Jun 7, 1995

Appl. No.:

8/477621

Inventors:

A. Maynard Engebretson - Ladue MO
Michael P. O'Connell - Somerville MA

Assignee:

K/S HIMPP - Vaerloese

International Classification:

H04R 7500

US Classification:

381106

Abstract:

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.

US Patent:

50162802, May 14, 1991

Filed:

Mar 23, 1988

Appl. No.:

7/172266

Inventors:

A. Maynard Engebretson - Ladue MO
Michael P. O'Connell - Maplewood MO
Baohua Zheng - University City MO

Assignee:

Central Institute for the Deaf - St. Louis MO

International Classification:

H04R 2500
H03B 2900

US Classification:

381 68

Abstract:

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.