US 5,138,664 AGranted

Noise reducing device

AssigneeSony Corporation

InventorsAkira Kimura, Tooru Sasaki, Nobuo Kobayashi

Life of this patent

Estimating the term…

Loading patent…

Abstract

This invention is concerned with a device for reducing the external noise reaching the ear in extremely noisy places such as in the vehicle or construction sites. According to the present invention, the external noise in picked up by a microphone provided in the vicinity of an electro-acoustic transducer element, such as a headphone unit, provided in the vicinity of the wearer's ear, and the noise signal converted in this manner into electrical signals is produced as the acoustic signal by the electro-acoustic transducer element. The transfer characteristics and controlled in such a manner that the produced noise signal prove to be an acoustic signal which is of the same frequency spectrum and opposite in phase with respect to the external noise reaching the wearer's acoustic meatus from outside to reduce the external noise reaching the acoustic meatus.

Claims8

Dependent claims

A noise reducing device in which an external noise reaching a user's acoustic meatus may be reduced by being acoustically combined with an acoustic signal output by an electro-acoustic transducer arranged facing a user's acoustic meatus when the noise reducing device is worn a user, comprising:

acoustic-electrical transducer means arranged in a direction away from the user's acoustic meatus and in the vicinity of said electro-acoustic transducer that faces toward the user's acoustic meatus for picking up the external noise exclusive of the output of the said electro-acoustic transducer and producing an output signal therefrom,
characteristics transfer means having predetermined phase and frequency transfer characteristics matched to acoustic frequency characteristics of the external noise for receiving said output signal form said acoustic-electrical transducer means and supplying an output signal to said electro-acoustic transducer that produces an acoustic signal therefrom, said characteristics transfer means including control means receiving said output signal from said acoustic-electrical transducer means for producing a phase-inverted output signal therefrom, and amplifier means having a variable gain for amplifying said phase-inverted output signal from said control means and supplying an amplified, phase-inverted signal to said electro-acoustic transducer,
wherein the phase and frequency transfer characteristic of said characteristics transfer means are predetermined so that the transfer characteristics from said acoustic-electrical transducer means to said electro-acoustic transducer means are in registry with and opposite in phase to acoustic frequency characteristics of the external noise, and
further comprising gain control means for detecting the output signal level of said acoustic-electrical transducer means and controlling the gain of said amplifier means in said characteristics transfer means in response thereto.

1 more element

A noise reducing device in which an external noise reaching a user's acoustic meatus may be reduced by an acoustic signal output by an electro-acoustic transducer arranged in the vicinity of the user's ear when the noise reducing device is worn by the user, comprising:

acoustic-electrical transducer means arranged in the vicinity of said electro-acoustic transducer means and directed in a direction away from the user's acoustic means and adapted to pick up the external noise in the vicinity of the user's ear exclusive of the output of electro-acoustic transducer,
control means supplied with the output of said acoustic-electrical transducer means for controlling the transfer characteristics of a signal input thereto by having predetermined phase and frequency transfer characteristics matched to acoustic frequency characteristics of the external noise and producing an output signal,
amplifier means having a variable gain for amplifying the output signal of said control means and supplying an amplified output signal to said electro-acoustic transducer,
signal summing means for summing an audio program signal for reproduction by said electro-acoustic transducer and said amplified output signal from said amplifier means and producing a summed signal fed to and input of said electro-acoustic transducer,
wherein the transfer characteristics of said control means are predetermined so that the transfer characteristics from said acoustic-electrical transducer means to said electro-acoustic transducer are in registry with and opposite in phase to the acoustic frequency characteristics of the external noise reaching the user's acoustic meatus, and the acoustic signal from the electro-acoustic transducer and the external noise are acoustically combined in the vicinity of the user's acoustic meatus, and
further comprising gain control means for detecting the output signal level of said acoustic-electrical transducer means and controlling the gain of said amplifier means in response thereto.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/493,432Filed 14 Mar 1990
Priority: JP 1-7527725 Mar 1989
Granted: 11 Aug 1992
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

G10K 11/17823
Characterised by the analysis of the input signals only: reference signals, e.g. ambient acoustic environment
G10K 11/17813
Characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions: characterised by the analysis of the…
G10K 11/1785
By electro-acoustically regenerating the original acoustic waves in anti-phase: methods, e.g. algorithms; Devices
G10K 11/17873
General system configurations: using a reference signal without an error signal, e.g. pure feedforward

Family

No related US applications are recorded in the indexed filing history.

Timeline

Citations

Open elsewhere

Building an agent or pulling many patents? Use the API or MCP server instead of scraping pages. Get an API key