面向远场语音识别的回声消除算法及应用验证  

Echo cancellation algorithm and application verification for far-field speech recognition

作　　者：司永凤 高云龙 王永娟[1] SI Yongfeng;GAO Yunlong;WANG Yongjuan(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学机械工程学院,南京210094

出　　处：《兵器装备工程学报》2022年第11期231-237,共7页Journal of Ordnance Equipment Engineering

基　　金：XXX创新项目(18-163-11-ZT-005-032-01)。

摘　　要：针对小型侦查类设备在执行远场监听工作时,由于复杂军事作战环境中回声影响系统识别率的问题,基于步长调整原则,提出了一种面向远场语音识别的回声消除改进算法,从根本上提高了输入语音信号的质量。该算法在归一化最小均方(normalized least-mean-square,NLMS)算法的基础上引入了双曲正弦函数,得到能够表示误差与步长之间关系的步长调整函数,通过误差值的大小实现了对步长值的实时调整;并基于MATLAB平台对NLMS算法、SVSLMS算法、基于双曲正弦函数的LMS改进算法以及文中NLMS改进算法做模拟仿真,对比结果可知,改进算法性能更优,在不增大收敛误差的条件下具有更快的收敛速度。进一步搭建嵌入式硬件平台对其实际性能进行测试,试验结果表明,系统识别加入回声后的语音时,词错误率高达60%以上,通过改进算法做语音增强后,系统词错误率明显降低,平均识别率约为80%,验证了基于双曲正弦函数的NLMS改进算法在实际应用中的有效性。Aiming at the problem that the echo affects the system recognition rate in the complex military combat environment when small reconnaissance equipment performs far-field monitoring,based on the step adjustment principle,an improved echo cancellation algorithm for far-field speech recognition was proposed,which fundamentally improves the quality of the input speech signal.Based on the normalized least mean square(NLMS)algorithm,the algorithm introduced a hyperbolic sinusoidal function to obtain a step adjustment function that can represent the relationship between error and step size,and realized the real-time adjustment of step size through the size of error value;The NLMS algorithm,SVSLMS algorithm,LMS improved algorithm based on hyperbolic sinusoidal function and NLMS improved algorithm in this paper were simulated based on MATLAB platform,the comparison results show that the improved algorithm has better performance and faster convergence speed without increasing the convergence error.The embedded hardware platform was further built to test its actual performance.The test results show that when the system recognizes the voice with echo,the word error rate is more than 60%.After speech enhancement by the improved algorithm,the word error rate of the system is significantly reduced,and the average recognition rate is about 80%.It verifies the effectiveness of the improved NLMS algorithm based on hyperbolic sinusoidal function in practical application.

关 键 词：远场语音识别 回声消除 双曲正弦函数 军事侦查 

分 类 号：TN912.34[电子电信—通信与信息系统]