Self-adaptive active noise reduction method for error-free microphone

Abstract

The invention discloses a self-adaptive active noise reduction method for an error-free microphone. According to the method, only one reference microphone is used for achieving active noise reduction;the method comprises the steps that firstly, transfer functions of a main channel and a secondary channel are estimated in advance, an error signal of a target noise-reduction point is estimated in real time by utilizing a received reference signal, and then weight coefficient vectors of a feedforward filter and a feedback filter are updated by using the error signal; the output of the feedforward filter and the output of the feedback filter are superimposed to obtain the output of an infrasound source. By means of the method, an error microphone required in a traditional self-adaptive activenoise reduction method is not needed, the problems of insufficient algorithm stability, complicated earphone structure and the like generally existing in traditional self-adaptive active noise reduction can be solved, and therefore the applicability and stability of the self-adaptive active noise reduction algorithm are greatly improved.

Description

technical field [0001] The invention relates to the field of active noise control, relates to an active noise control method, in particular to an adaptive active noise reduction method for an error-free microphone. Background technique [0002] Active Noise Control (ANC) is a technology that uses a secondary sound source to generate a sound wave with the same frequency as the noise but opposite in phase to counteract the noise. Since active noise control has a better control effect on low-frequency noise than passive noise reduction methods, its application in active noise reduction headphones and other fields has attracted extensive attention. [0003] The control mode of active noise reduction headphones can be divided into two types: fixed filter and adaptive filter. Limited by the development of electronics, active noise control in the early years was all based on analog electronic technology. Due to the low flexibility of the analog circuit, only the control mode of t...

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Problems solved by technology

[0007] The purpose of the present invention is to overcome the defects of the current self-adaptive active noise reduction system, propose an adaptive active noise reduction method for an error-free microphone, obtain the main channel and secondary channel transfer functions of the earphone through the method of offline self-adaptive system identification, And use the reference microphone signal and the secondary sound source output signal to filter the main channel and secondary channel respectively to obtain the primary noise and secondary noise, so as to estimate the error signal at the human ear, and reduce the noise through an adaptive algorithm

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