A Combined De-correlation Method for Acoustic Feedback Cancellation in Hearing Aids

Acoustic feedback is a common problem in most hearing aids, it reduces the maximum useable gain and even causes "howling" while large forward gain is required, which is quite annoying for patient with severe hearing losses. This paper gives a new combination of de-correlation LMS adaptive algorithm and fixed forward delay to better de-correlate input and output signals of hearing aids as well as input signals to adaptive filters in consecutive time. Simulations in MATLAB showed that more than 20 dB additional gain could be obtained with new method.