Noise canceling system and method, smart control method and device and communication equipment

Patent metadata

Field	Value
Publication number	US-9379751-B2
Application number	US-201114119611-A
Country	US
Kind code	B2
Filing date	Nov 8, 2011
Priority date	Sep 10, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

The present invention discloses a noise canceling system and method, a smart control method and device and a communication equipment. Said smart control method includes: when it is detected there is no voice signal output at a receiving end of a communication equipment, receiving an outside noise signal from a reference microphone away from ears and a detection signal from a monitoring microphone near ears; implementing performance analysis on said received outside noise signal and said detection signal to estimate a noise reduction performance curve after said feed-forward active noise cancellation; and regulating parameters of the control circuit in said feed-forward active noise cancellation according to said estimated noise reduction performance curve and the preset noise reduction performance curve to make a difference between said estimated noise reduction performance curve and said preset noise reduction performance curve within a preset range.

First claim

What is claimed is:

1. A non-closed feed-forward active noise canceling method, comprising:
picking up an outside noise signal away from ears;
subjecting the picked outside noise signal to feed-forward active noise cancellation to generate an anti-noise signal for balancing out said outside noise signal;
mixing the generated anti-noise signal and a voice signal received at the receiving end of the communication equipment; and
feeding the mixed signal into the ears to balance out the outside noise signal entering the ears via free space,
wherein, when it is detected that there is no voice signal output at the receiving end of said communication equipment, regulating the parameters of the control circuit used in said feed-forward active noise cancellation,
wherein, the step of when it is detected there is no voice signal output at a receiving end of a communication equipment, regulating the parameters of the control circuit used in said feed-forward active noise cancellation comprises:
receiving an outside noise signal from a reference microphone away from the ears and a detection signal from a monitoring microphone near the ears;
within a band range of 500 Hz˜1 kHz, analyzing the performance of said received outside noise signal and said detection signal to estimate a noise reduction performance curve about the noise reduction performance after said feed-forward active noise cancellation; and
regulating parameters of the control circuit used for said feed-forward active noise cancellation according to the estimated noise reduction performance curve and a preset noise reduction performance curve, so as to, within the band range of 500 Hz˜1 kHz, make a difference between said estimated noise reduction performance curve and said preset noise reduction performance curve within a preset range, and

wherein the parameters of said control circuit comprise a gain factor and phase adjustment parameters.

2. The non-closed feed-forward active noise canceling method of claim 1 , wherein regulating parameters of the control circuit used for said feed-forward active noise cancellation according to said estimated noise reduction performance curve and the preset noise reduction performance curve comprises:
comparing said estimated noise reduction performance curve with the preset noise reduction performance curve to determine regulation direction in which parameters of said control circuit need to be regulated; and
regulating parameters of said control circuit according to the determined regulation direction, wherein,
said regulation process for parameters of the control circuit applies feedback control, and each time after regulation, comparing whether said estimated noise reduction performance curve approaches closer to said preset noise reduction performance curve; if so, maintaining the regulation direction, if not, reversing said regulation direction, until the difference between said estimated noise reduction performance curve and said preset noise reduction performance curve is within said preset range.

3. The non-closed feed-forward active noise canceling method of claim 1 , wherein detecting whether there is any voice signal output at the receiving end of the communication equipment is implemented by calculating correlation between said outside noise signal and said detection signal or determining the value of energy of output signal of said receiving end.

4. The non-closed feed-forward active noise canceling method of claim 3 , wherein detecting whether there is any voice signal output at the receiving end of said communication equipment by calculating the correlation between said outside noise signal and said detection signal comprises:
subjecting signals picked by said reference microphone and said monitoring microphone to framing processing respectively;
calculating the correlation between two frames of data having been subjected to said framing; and
comparing the calculated correlation with a predetermined threshold to determine the correlation between signals picked respectively by said reference microphone and said monitoring microphone.

5. A device for non-closed feed-forward active noise cancellation, comprising:
a reference microphone configured to pick up an outside noise signal away from ears;
an anti-noise signal generating unit configured to subject the picked outside noise signal to feed-forward active noise cancellation to generate an anti-noise signal for balancing out said outside noise signal;
a signal mixing unit configured to mix said anti-noise signal and a voice signal received at the receiving end of the communication equipment;
a feed-in unit configured to feed the mixed signal into the ears;
a monitoring microphone configured to pick up the detection signal near the ears, said detection signal being a signal obtained by superposing, at the ears, the outside noise signal entering the ears via free space and the output signal of said feed-in unit; and
a smart control device, configured to regulate parameters of the control circuit for feed-forward active noise cancellation of said anti-noise signal generating unit when there is no voice signal output is detected at said receiving end of the communication equipment,
wherein the smart control device comprises:
a detecting unit configured to detect whether there is any voice signal output at the receiving end of the communication equipment;
a receiving unit configured to, when it is detected there is no voice signal output at said receiving end of a communication equipment, receive an outside noise signal from a reference microphone away from the ears and a detection signal from a monitoring microphone near the ears;
a noise reduction performance estimating unit configured to implement performance analysis, within a band range of 500 Hz˜1 kHz, on said received outside noise signal and said detection signal to estimate a noise reduction performance curve after said feed-forward active noise cancellation; and
a first regulating unit configured to regulate parameters of the control circuit in said feed-forward active noise cancellation according to said estimated noise reduction performance curve and the preset noise reduction performance curve, so as to, within the band range of 500 Hz˜1 kHz, make a difference between said estimated noise reduction performance curve and said preset noise reduction performance curve within a preset range.

6. The device for non-closed feed-forward active noise cancellation according to claim 5 , wherein said first regulating unit comprises:
a regulation direction determining module configured to compare said estimated noise reduction performance curve with the preset noise reduction performance curve to determine regulation direction in which the parameters of said control circuit need to be regulated; and
a second regulating module configured to regulate parameters of said control circuit according to the determined regulation direction;
wherein said regulation process for parameters of the control circuit applies feedback control, and each time after regulation, comparing again whether said estimated noise reduction performance curve approaches closer to said preset noise reduction performance curve; if so, maintaining the regulation direction, if not, reversing said regulation direction, until the difference between said estimated noise reduction performance curve and said preset noise reduction performance curve is within said preset range.

7. The device for non-closed feed-forward active noise cancellation of claim 5 , wherein said detecting unit determines whether there is any voice signal output at said receiving end by calculating the correlation of signals picked respectively by said reference microphone and said monitoring microphone or by detec

Assignees

• Liu Song
• Zhao Jian
• Lou Shasha
• Goertek Inc

Inventors

• Liu Song
• Zhao Jian
• Lou Shasha

Classifications

• H04R1/1083 Primary

  Reduction of ambient noise (active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06) · CPC title

• H04R2460/01

  Hearing devices using active noise cancellation · CPC title

• H04R2499/13

  Acoustic transducers and sound field adaptation in vehicles · CPC title

• H04R3/02

  for preventing acoustic reaction {, i.e. acoustic oscillatory feedback (specially adapted for hearing aids H04R25/453)} · CPC title

• H04R2410/05

  Noise reduction with a separate noise microphone · CPC title