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。在复杂环境中采用自适应指向性的传声器系统能够动态调整指向性模式,以适应噪声的变化情况。基于自适应最小均方(LMS)算法提出了一种新的适用于助听器的自适应算法,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。相比于经典的LMS算法,该算法有效改善了期望信号存在时的失调情况。通过仿真结果讨论了算法中关键参数的选取对于失调并和收敛速度的影响。
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.Adaptive directional microphones could adjust the directional pattern over time for responding to noise variation in complicated environment.A novel adaptive algorithm based on Least Mean Square（LMS） is pro-posed 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 classical LMS,the proposed algorithm can im-prove the misalignment in presence of desired sound.Finally,simulation results are discussed to show how some key parameters affect misalignment and convergence rate.
出处
《声学技术》
CSCD
2011年第3期270-274,共5页
Technical Acoustics
基金
中国科学院"科技助残行动计划"项目(KGCX‐YW‐616)
关键词
自适应算法
指向性传声器
指向性模式
失调
adaptive algorithm
directional microphones
directional pattern
misalignment
