Active denoising system for flexibly adjusting denoising signal time delay

一种信号延时、主动降噪的技术，应用在听筒/耳机附件、频率响应校正等方向，能够解决主动降噪失去效果、降低降噪滤波器精度、影响降噪效果等问题，达到增加延时、降低精度、加强降噪效果的效果

Active Publication Date: 2018-04-06
BESTECHNIC SHANGHAI CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But the digital solution introduces delay problems, including AD conversion delay, DA conversion delay, down-sampling or up-sampling filter delay
If the delay is too large, the anti-phase sound wave cannot be generated, and the active noise reduction will lose its effect; if the delay is too small, the audio sampling rate of the active noise reduction work is required to be high, but this will reduce the accuracy of the noise reduction filter, which cannot be very effective. Good fit to the frequency response of the microphone and speaker, affecting the noise reduction effect

Method used

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Embodiment Construction

[0031] The objects and functions of the present invention and methods for achieving the objects and functions will be clarified by referring to the exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in various forms. The essence of the description is only to help those skilled in the relevant art comprehensively understand the specific details of the present invention.

[0032] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, and related technical terms should be familiar to those skilled in the art. In the drawings, the same reference numerals represent the same or similar components, or the same or similar steps, unless otherwise specified. Below by specific embodiment content of the present invention is described, as figure 1 The schematic diagram of the signal transmission of the active noise reduction system that flexibly ...

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PUM

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Abstract

The invention provides an active denoising system for flexibly adjusting denoised signal time delay. The system comprises a noise collection channel and a music playing channel. The noise collection channel comprises a microphone, an AD converter, a denoising filter, a phase-locked loop which accesses the AD converter and has an adjustable clock frequency, and a first time delay control unit whichis connected between the AD converter and the denoising filter. The music playing channel comprises a music playing source, a first upsampling filter, an adder, a DA converter, a player, and a secondtime delay control unit which is connected between the adder and the DA converter. The adder is used for coupling and superposing a noise reference signal processed by the denoising filter and a music signal processed by the first upsampling filter, thereby outputting a mixed signal. The active denoising system provided by the invention is applicable to different earphone plugs, frequency response of the microphone and the player can be fitted well, and a relatively good denoising effect is realized.

Description

technical field [0001] The invention relates to the technical field of earphone noise reduction, in particular to an active noise reduction system for flexibly adjusting the delay of a noise reduction signal. Background technique [0002] Active noise reduction earphones use the active noise reduction system to emit sound waves in phase opposite to the ambient noise to offset the noise sound waves and eliminate the ambient noise, thereby achieving the effect of noise reduction. The specific principle is to use an external microphone to collect external noise, and then use the active noise reduction system to generate an anti-phase sound wave with the same amplitude as the noise and a phase difference of 180 degrees to cancel the noise, thereby achieving noise reduction. The specific function of the active noise reduction earphone is to reduce the external environmental noise and provide a quiet environment for the wearer. [0003] At present, after a lot of research and dev...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04R1/10H04R3/04
Inventor 杨磊
Owner BESTECHNIC SHANGHAI CO LTD
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