一种适用于助听器的低失调自适应指向性算法  

A low-misadjustment adaptive directional algorithm for hearing aids

作　　者：张云翼[1] 崔杰[1] 肖灵[1] 

机构地区：[1]中国科学院声学所医用声学实验室,北京市100080

出　　处：《信号处理》2011年第2期241-245,共5页Journal of Signal Processing

基　　金：中国科学院"科技助残行动计划"项目-高性能数字助听器(KGCX-YW-616)

摘　　要：在噪声环境中助听器的性能会受到严重影响。但当噪声与期望信号处在不同方向时,在助听器中使用指向性传声器系统能够有效地抑制噪声,使助听器的使用者受益。本文基于自适应LMS(最小均方)算法提出了一种适用于助听器的低失调自适应指向性算法,用以动态调整传声器系统中滤波器的系数,使指向性模式的灵敏度最低点朝向噪声源方向,达到降噪的目的。相比于现有的LMS算法,本文引入了一种后验信噪比并将与其相关的信噪比补偿因子引入自适应步长的更新过程,有效改善了语音信号存在时的失调情况。最后,本文通过仿真验证了本文算法对失调的改善作用。The performance of hearing aids may degrade severely in noisy environment.If noise and desired sound are at different directions,a directional microphones system is able to suppress the noise in hearing aids and benefit the hearing-impaired.A low-misadjustment adaptive directional algorithm based on LMS（Least Mean Square） for hearing aids is proposed in this paper.The proposed algorithm is designed for updating coefficients of the adaptive FIR so that the null of directional pattern would face the direction of noise. Compared to the available LMS,the proposed algorithm brings in a posteriori SNR and a related SNR compensation factor to update the step so that misadjustment is improved in presence of desired sound.Finally,improvement of misadjustment has been verified by simulation results.

关 键 词：自适应指向性算法 低失调 后验信噪比 信噪比补偿因子 

分 类 号：TN912[电子电信—通信与信息系统]