The Research And Improvement On Feedback Cancellation Of Digital Hearing Aids

For hearing impaired patients,digital hearing aids are an indispensable tool in their lives and can improve their hearing level.Echo feedback phenomenon is a common problem in the use of digital hearing aids.This paper focuses on the study of echo feedback cancellation technology in hearing aids.The main work includes:Firstly,This paper analyzes the phonetic mechanism of speech and human auditory model,and studies the basic theory of phonetics.It mainly introduces several key techniques used in digital hearing aids,including echo feedback cancellation,loudness compensation,sound source localization and speech enhancement,Which focuses on the echo cancellation algorithm research status and development.Secondly,In traditional NLMS algorithm,the performance will be seriously degraded when dealing with the strongly correlated speech signal.This paper will focus on the application of Affine Projection Algorithm(APA)in echo cancellation.In this paper,a new variable APA based on the discrete cosine transform is proposed.Compared with the traditional algorithm,the proposed algorithm has better performance than the traditional algorithm.The proposed algorithm achieves a faster convergence rate and a lower steady-state offset,which improves the effectiveness of the algorithm.Finally,Due to the repeated use of speech data,the affine projection algorithm is computationally complex,which affects the real-time performance of digital hearing aids.In this paper,the variable projection algorithm is added on the basis of the variable step-size projection algorithm,and the projection order of the algorithm is reduced in the iterative process,which reduces the computational complexity.The simulation results show that the proposed algorithm can reduce the computational complexity and ensure the real-time performance of the proposed algorithm while maintaining the convergence rate and steady-state offset.