TY - JOUR
T1 - Acoustic feedback cancellation in hearing aids using dual adaptive filtering and gain-controlled probe signal
AU - Akhtar, Muhammad Tahir
AU - Albu, Felix
AU - Nishihara, Akinori
N1 - Funding Information:
The authors would like to thank Prof. J. Kates for providing the MATLAB implementations of the HAAQI and HASQI measures. Authors would like to acknowledge anonymous reviewer for providing many critical and insightful comments, which has greatly helped in improving the contents as well as quality of presentation. This research has been funded from the Faculty Development Competitive Research Grants Program of Nazarbayev University.
Publisher Copyright:
© 2019 The Author(s)
PY - 2019/7
Y1 - 2019/7
N2 - In this paper, we propose a probe signal-based adaptive filtering method for acoustic feedback cancellation (AFC) in hearing aids. The proposed method consists of two adaptive filters. The first adaptive filter is excited by the receiver (loudspeaker) signal, and uses the microphone signal as its desired response. The first adaptive filter shows a fast convergence speed, however, it may converge to a biased solution at the steady-state because its input and desired response are correlated with each other. The second adaptive filter is excited by an internally generated (uncorrelated) probe signal. The two adaptive filters are adapted using a delay-based normalized least mean square (NLMS) algorithm. A strategy is devised to exchange the coefficients of two adaptive filters such that the both adaptive filters give a good (unbiased) estimate of the acoustic feedback path. Furthermore, we propose to vary the gain of the probe signal, such that a high level probe signal is injected during the transient state, and a low level probe signal is used after the AFC system has converged. The computer simulations demonstrate that the proposed method achieves good modeling accuracy, preserves good speech quality, and maintains high output SNR at the steady-state.
AB - In this paper, we propose a probe signal-based adaptive filtering method for acoustic feedback cancellation (AFC) in hearing aids. The proposed method consists of two adaptive filters. The first adaptive filter is excited by the receiver (loudspeaker) signal, and uses the microphone signal as its desired response. The first adaptive filter shows a fast convergence speed, however, it may converge to a biased solution at the steady-state because its input and desired response are correlated with each other. The second adaptive filter is excited by an internally generated (uncorrelated) probe signal. The two adaptive filters are adapted using a delay-based normalized least mean square (NLMS) algorithm. A strategy is devised to exchange the coefficients of two adaptive filters such that the both adaptive filters give a good (unbiased) estimate of the acoustic feedback path. Furthermore, we propose to vary the gain of the probe signal, such that a high level probe signal is injected during the transient state, and a low level probe signal is used after the AFC system has converged. The computer simulations demonstrate that the proposed method achieves good modeling accuracy, preserves good speech quality, and maintains high output SNR at the steady-state.
KW - Acoustic feedback
KW - Hearing aids
KW - NLMS algorithm
KW - Probe signal
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U2 - 10.1016/j.bspc.2019.03.012
DO - 10.1016/j.bspc.2019.03.012
M3 - Article
AN - SCOPUS:85063265093
SN - 1746-8094
VL - 52
SP - 1
EP - 13
JO - Biomedical Signal Processing and Control
JF - Biomedical Signal Processing and Control
ER -
