Feedback cancellation in hearing aids: An unbiased modelling approach

In this paper, we present an unbiased adaptive modelling approach to feedback cancellation in hearing aids. The approach is based on a closed loop identification of the feedback path as well as the (linear prediction) model of the near-end input signal. In general, both models are not simultaneously identifiable in the closed loop system at hand. We show that -under certain conditions e.g. if a delay is inserted in the forward path- identification of both models is indeed possible. Simulation results demonstrate that -under these conditions- the unbiased modelling approach outperforms the biased continuous adaptation algorithm.