A Study Of Echo Cancellation Algorithm In Digital Hearing Aid

Hearing aid is one of the most commonly used and most effective medical devices to compensate for hearing loss.However,for a long time,the echo phenomenon is the most common problem of the hearing aid users,so how to eliminate the echo has been a key task in the digital hearing aid technology.The acoustic echo path is inevitable in hearing aids is the essential reasons of the echo,so the adaptive filtering method is the most commonly used in digital hearing aid echo cancellation method,through to the echo path of real-time changes in the adaptive Ying Jianmo constantly adjust the weights of filter parameters,to obtain the echo path estimation,and signal echo,and subtract it from the output of the hearing aid,so as to effectively eliminate echo howling produced,greatly improve the hearing aid output sound quality.The research of digital hearing aid in above process,echo cancellation principle and adaptive filter theory,discussed based on least mean square criterion and affine projection criterion based on the two kinds of adaptive echo cancellation algorithm.The minimum mean square(LMS,Least Mean Square)algorithm,normalized least mean square(NLMS Normalized,Least Mean Square)algorithm,the leakage type normalized least mean square(LNLMS,Leaky Normalized Least Mean Square)algorithm,the proportion of normalized least mean square(PNLMS,Proportionate Normalized Least Mean Square)algorithm,the normalized segmented proportion LMS(SPNLMS,Proportionate Normalized Least Mean Square)algorithm,delay LMS(DLMS,Delay Least Mean Square)algorithm,Proportionate affine projection algorithm(Proportionate Affine Projection Algorithm,PAPA),the proportion of the improved affine projection algorithm(Improved Proportion Affine Projection Algorithm,IPAPA),IPAPA(Combined IPAPA convex combination algorithm,CIPAPA)the complexity,convergence speed and steady-state error,tracking performance and other aspects of in-depth analysis and comprehensive comparison and discussion.Finally,using the United States MIT(Massachusetts Institute of Technology)multimedia laboratory database of the echo path is simulated for real speech signals,the digital hearing aid echo corresponding eliminating software simulation platform,the platform can be through friendly interface verification and understand the validity and reliability of algorithm.The platform can choose different background environment,can set the signal to noise ratio,and can verify the validity and reliability of different algorithms through a friendly interactive interface.