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Self-adaptive digital active noise reduction framework

An active noise reduction and self-adaptive technology, which is applied in the direction of sound-emitting devices and instruments, can solve the problem of poor noise reduction effect and achieve the effect of improving the noise reduction effect

Inactive Publication Date: 2019-03-29
SICHUAN CHANGHONG ELECTRIC CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide an adaptive digital active noise reduction architecture, which is used to solve the problem that the traditional adaptive architecture in the prior art has poor noise reduction effect on some non-causal frequency bands

Method used

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Examples

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Effect test

Embodiment 1

[0019] combined with figure 1 As shown, an adaptive digital active noise reduction architecture includes a reference microphone in the feedforward channel, an ADC connected to the reference microphone in sequence, a high-pass filter and a feedforward adaptive filter, and an error sensor in the feedback channel, An ADC and a high-pass filter connected in sequence with the error sensor, the output end of the high-pass filter of the feedforward channel is also connected with a feedforward fixed filter, and the output end of the high-pass filter of the feedback channel is connected with the feedforward adaptive filter, The output end of the high-pass filter of the feedback channel is also connected with a feedback fixed filter, and the output signals of the feedforward fixed filter, the feedforward adaptive filter and the feedback fixed filter are superimposed and then digital-to-analog converted and output by the speaker .

[0020] Since the feedforward adaptive filter only perf...

Embodiment 2

[0022] On the basis of Example 1, in conjunction with the attached figure 1 and figure 2 As shown, an automatic amplitude control circuit for amplifying / decreasing the signal amplitude is also connected between the output end of the high-pass filter of the feedback channel and the output end of the feedforward adaptive filter.

[0023] Since the feedforward adaptive filter usually uses a fixed-point algorithm, by adding an automatic amplitude control circuit, the coefficient of the feedforward adaptive filter can still be updated when the error signal amplitude is small, so as to achieve the optimal effect , which solves the lack of precision in fixed-point arithmetic.

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Abstract

The invention discloses a self-adaptive digital active noise reduction framework. The framework comprises a reference microphone, a first analog-digital converter, a first high-pass filter and a feedforward self-adaptive filter which are connected in sequence. The framework further comprises an error sensor, a second analog-digital converter and a second high-pass filter which are connected in sequence. The output end of the first high-pass filter is further connected with a feedforward fixed filter, the output end of the second high-pass filter is connected with the feedforward self-adaptivefilter, the output end of the second high-pass filter is further connected with a feedback fixed filter, and after being superposed, signals of output ends of the feedforward fixed filter, the feedforward self-adaptive filter and the feedback fixed filter are subjected to digital-to-analogue conversion and output by a loudspeaker. Noise reduction waves generated by the fixed filters are superposedwith noise reduction waves generated by the self-adaptive filter, so that defects of pure self-adaptive framework in the aspect of noise reduction effect are overcome; an automatic amplitude controlcircuit is additionally arranged in an error microphone sampling channel so as to overcome the precision defect of fixed-point operation.

Description

technical field [0001] The invention relates to the technical field of noise control, in particular to an adaptive digital active noise reduction architecture. Background technique [0002] With the gradual improvement of people's awareness of noise pollution, the demand for noise reduction is increasing. Living and working in a low-noise environment can effectively protect hearing on the one hand, and maintain a relatively good mood on the other hand to improve work efficiency. In the current environmental noise, passive noise reduction can effectively shield high-frequency noise, but the effect on low-frequency noise is not satisfactory, and active noise reduction can just solve the noise reduction problem of low-frequency noise, so the current active noise reduction technology The application in life and work is gradually increasing. Active noise reduction refers to the use of electronic circuits to generate signals with the same frequency, opposite phase, and consistent...

Claims

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Application Information

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IPC IPC(8): G10K11/178
CPCG10K11/17853G10K11/17854G10K11/17879G10K11/17881
Inventor 李想余世泉蒲显城韩大强姜志强
Owner SICHUAN CHANGHONG ELECTRIC CO LTD
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