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Scene adaptive active noise reduction method and earphone

An active noise reduction and adaptive technology, applied in active noise cancellation hearing devices, earpiece/headphone accessories, sensors, etc., can solve the problems of slow convergence of active noise reduction and poor broadband noise control effect.

Active Publication Date: 2018-11-27
SICHUAN CHANGHONG ELECTRIC CO LTD
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  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a scene-adaptive active noise reduction method and earphones, which are used to solve the problems in the prior art that the FXLMS algorithm is used for active noise reduction, the convergence speed is slow, and the control effect on broadband noise is poor

Method used

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  • Scene adaptive active noise reduction method and earphone
  • Scene adaptive active noise reduction method and earphone
  • Scene adaptive active noise reduction method and earphone

Examples

Experimental program
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Effect test

Embodiment 1

[0055] combined with figure 1 and figure 2 As shown, a scene adaptive active noise reduction method, including:

[0056] Step S1: the microphone picks up the ambient noise and converts it into a primary noise electrical signal;

[0057] Step S2: The noise identification module extracts noise energy concentration frequency bands and frequency distribution characteristics according to the primary noise electrical signal, and matches with the preset noise patterns in the noise pattern library to determine the noise type;

[0058] Step S3: Select EQ filter parameters from the filter library and load them into the active noise reduction module, the EQ filter parameters include center frequency f, bandwidth Q and gain amount GAIN;

[0059] Step S4: The active noise reduction module performs adaptive filtering on the primary noise electrical signal, and generates a noise cancellation electrical signal to excite the speaker;

[0060] It specifically includes: step S41: the EQ filt...

Embodiment 2

[0069] On the basis of Embodiment 1, the step S44 specifically includes:

[0070] A. Solve the signal e(n) received by the error sensor, specifically:

[0071] The input signal X(n) of the active noise reduction module will reach the error sensor through the main channel P(z) and the secondary channel. The output of the secondary channel is expressed as: At this time, if it is assumed that the weight coefficient of the adaptive filter W(z) remains unchanged in a short period of time L, let r(n)=x(n)*s(n), we can get At this time, the signal e(n) received by the error sensor is the sum of the output signals of the main channel P(z) and the secondary channel, namely:

[0072] e(n)=d(n)+s(n)=d(n)+r T (n)W(n), wherein d(n) is the output signal after the signal X(n) passes through the main channel P(z), and W(n) is the transfer function of the adaptive filter;

[0073] B. Solve the optimal weight coefficient of the adaptive filter, specifically:

[0074] Choose the minimum me...

Embodiment 3

[0081] On the basis of embodiment 2, in conjunction with the attached image 3As shown, there are two EQ filters, one of which is used to receive the secondary channel transfer function identification result The output signal is filtered and then input to the adaptive filter W(z), and another EQ filter is used to receive the signal e(n) received by the error sensor and is filtered and then input to the adaptive filter W(z).

[0082] From the second calculation method of calculating the optimal weight coefficient vector, it can be seen that the noise energy of signals with different frequency distribution characteristics will also be concentrated in different frequency bands. Therefore, in order to enhance the noise reduction effect of the active noise reduction module on a certain scene, The active noise reduction module introduces two EQ filters to enhance the processing of frequency bands where noise is concentrated. After adding the EQ filter, the selected frequency band ...

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Abstract

The invention discloses a scene adaptive active noise reduction method, which comprises the steps of: picking up environmental noise and converting into a primary noise electrical signal; determiningthe noise type by a noise recognition module; selecting an EQ filter parameter from a filter library to load an active noise reduction module; carrying out adaptive filtration on the primary noise electrical signal by the active noise reduction module to generate a noise reduction electrical signal for exciting a speaker; generating a noise reduction wave by the speaker after receiving the noise reduction electrical signal, and emitting a second canceling audio signal, wherein the noise reduction wave has the same spectral distribution as the primary noise electrical signal, and the sound pressure is the same in magnitude and opposite in phase. A scene adaptive active noise reduction earphone comprises a microphone, a speaker and an active noise reduction module. The noise reduction earphone can adjust the EQ filter parameters in the FXLMS noise reduction algorithm according to the difference of the noise energy concentration region in the noise scene, and cancel the noise which cannotbe removed by the passive noise reduction, thereby improving the effect of the external noise of the scene of the human ear to the earphone export audio.

Description

technical field [0001] The invention relates to the field of noise reduction earphones, in particular to a scene adaptive active noise reduction method and earphones. Background technique [0002] With the increasing frequency of people's traffic, environmental noise has seriously affected the quality of travel. Traditional noise reduction methods mainly include sound insulation, material absorption, etc., but limited by factors such as layout space, material characteristics, and cost, traditional methods are better for high-frequency noise removal, but not ideal for low-frequency noise. Therefore, active noise reduction has gradually entered the public life from the field of civil aviation and military affairs. Different from traditional noise reduction methods, active noise control (ANC) uses the principle of sound wave interference and cancellation, and uses secondary sound sources to offset the original noise to achieve noise cancellation. Active noise reduction can au...

Claims

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Application Information

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IPC IPC(8): H04R1/10
CPCH04R1/1091H04R2460/01
Inventor 陈龙
Owner SICHUAN CHANGHONG ELECTRIC CO LTD
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