Steady-state analysis of continuous adaptation in acoustic feedback reduction systems for hearing-aids

Author

Siqueira, Marcio G. ; Alwan, Abeer

Author_Institution

Dept. of Electr. Eng., California Univ., Los Angeles, CA, USA

Volume

8

Issue

4

fYear

2000

fDate

7/1/2000 12:00:00 AM

Firstpage

443

Lastpage

453

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 used in continuous adaptation to reduce acoustic feedback. A bias is found in the adaptive filter´s estimate of the hearing-aid acoustic feedback path. Methods for reducing this bias and producing an improved estimate of the acoustic feedback path are analyzed and compared. It is shown that by the use of a delay in the forward or cancellation paths of the hearing aid plant, and for representative feedback paths, it is possible to reduce this bias by more than 15 dB

Keywords

acoustic signal processing; adaptive filters; adaptive signal processing; delays; feedback; filtering theory; hearing aids; LMS-based adaptive algorithms; acoustic feedback reduction systems; adaptive filter estimate; bias reduction; cancellation paths; continuous adaptation; delay; feedback paths; forward paths; gain; hearing-aids; in-the-ear hearing aids; open molds; steady-state analysis; steady-state convergence; vented molds; Acoustic devices; Adaptive algorithm; Adaptive filters; Algorithm design and analysis; Auditory system; Convergence; Delay; Feedback; Hearing aids; Steady-state;

fLanguage

English

Journal_Title

Speech and Audio Processing, IEEE Transactions on

Publisher

ieee

ISSN

1063-6676

Type

jour

DOI

10.1109/89.848225

Filename

848225