Improved Adaptive Feedback Cancellation in Two Microphone Hearing Aids with a Novel Bias Reduction Technique

In hearing aids (HAs), adaptive feedback cancellation (AFC) is used widely to reduce unwanted feedback. The prediction error method-based adaptive feedback cancellation (PEM-AFC2) in a two-microphone system is a recently proposed approach in which it is considered that there is negligible presence of the second microphone feedback signal due to its distant position from the speaker. In real-life scenarios, this assumption is impractical, especially with the compact structure of hearing aid devices placing the speaker and microphones in close proximity. To address this issue which results in undesired bias in the feedback path estimate, a novel adaptive method, named improved PEM-AFC2, is introduced in this paper.