存在声反馈的前馈有源降噪耳机设计方法  

Design of feedforward active noise canceling earphones with acoustic feedback

作　　者：郭剑锋 高智超 刘思辰 杨飞然[2] GUO Jianfeng;GAO Zhichao;LIU Sichen;YANG Feiran(Taiyuan University of Technology,Taiyuan 030024,China;Key Laboratory of Noise and Vibration Research,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;Xi’an Jiaotong-Liverpool University,Suzhou 215123,China)

机构地区：[1]太原理工大学,太原030024 [2]中国科学院声学研究所噪声与振动重点实验室,北京100190 [3]西交利物浦大学,苏州215123

出　　处：《应用声学》2024年第5期956-963,共8页Journal of Applied Acoustics

基　　金：国家自然科学基金项目(12204345,62171438);山西省自然科学基金项目(202103021223107,20210302123188);声场声信息国家重点实验室开放课题(SKLA202116)。

摘　　要：现有的前馈有源降噪耳机几乎都是采用扬声器后腔与参考传声器密封隔离的结构,该设计避免了次级声反馈,但也导致最优控制器的难以优化设计的问题。该文提出了一种新的存在声反馈的前馈有源降噪耳机结构,其中参考传声器入声孔朝向人耳且处于扬声器后腔中。针对这种新的有源降噪耳机结构,推导了最优控制器的表达式,提出采用多个级联的二阶IIR滤波器来逼近该最优控制器,将最优控制器的设计建模为一个多约束多参数优化问题,采用差分进化算法来寻找参数向量的全局最优解。实验发现,采用新结构的有源降噪耳机具有更加平滑的最优控制器频响曲线,因此需要更少的滤波器资源。测试结果表明,采用新结构的有源降噪耳机具有更宽的降噪频带和更高的降噪深度且不存在啸叫等问题。Almost all the existing feedforward active noise-canceling earphones use a structure in which the rear chamber of the loudspeaker is sealed and isolated from the reference microphone.This design avoids secondary acoustic feedback,but it is difficult to design the optimal controller.This paper proposes a new feedforward structure with acoustic feedback,in which the sound inlet of the reference microphone faces the ear and is located in the rear cavity of the speaker.With this new structure,we derive the expression of the optimal controller,and propose to adopt cascade Biquad filters to approximate the optimal controller.The optimal controller design is modeled as a multi-constraint multi-parameter optimization problem,and the differential evolution algorithm is used to find the global optimal solution of the parameter vector.Experiments have found that the designed earphone has a smoother optimal controller frequency response curve than traditional one,so the former requires less filter resources.The test results show that the proposed earphone achieves larger bandwidth and higher noise reduction and without any stability problems such as howling.

关 键 词：有源噪声控制 声反馈 前馈控制 

分 类 号：TP302.1[自动化与计算机技术—计算机系统结构]