Title :
Steady-state analysis of continuous adaptation systems in hearing aids
Author :
Siqueira, M.G. ; Alwan, A. ; Speece, R.
Author_Institution :
Dept. of Electr. Eng., California Univ., Los Angeles, CA, USA
Abstract :
Acoustic feedback is a problem in hearing aids that contain a substantial amount of gain, hearing aids that are used in conjunction with vented or open molds, and in-the-ear hearing aids. Acoustic feedback is both annoying and reduces the maximum usable gain of hearing-aid devices. This paper studies analytically the steady-state convergence behavior of LMS-based adaptive algorithms when operating in continuous adaptation to reduce acoustic feedback. A bias is found in the adaptive filter´s estimate of the hearing-aid feedback path. A method for reducing this bias and producing an improved estimate of the feedback path is analyzed. It is shown that by the use of delays in the forward path of the hearing aid plant, it is possible to reduce the bias considerably
Keywords :
acoustic signal processing; adaptive filters; adaptive signal processing; convergence of numerical methods; correlation methods; delays; feedback; filtering theory; handicapped aids; hearing aids; least mean squares methods; LMS-based adaptive algorithms; acoustic feedback; adaptive filter estimate; bias reduction; continuous adaptation systems; correlated inputs; forward path delay; gain; hearing-aid devices; hearing-aid feedback path; in-the-ear hearing aids; open molds; speech-shaped noise; steady-state analysis; steady-state convergence; vented molds; white noise; Acoustic devices; Adaptive algorithm; Adaptive filters; Algorithm design and analysis; Auditory system; Convergence; Delay; Feedback; Hearing aids; Steady-state;
Conference_Titel :
Applications of Signal Processing to Audio and Acoustics, 1997. 1997 IEEE ASSP Workshop on
Conference_Location :
New Paltz, NY
Print_ISBN :
0-7803-3908-8
DOI :
10.1109/ASPAA.1997.625582
