Joint Acoustic Feedback Cancellation and Noise Reduction Within the Prediction Error Method Framework

The principal aim of this work is to study the problem of Acoustic Feedback Cancellation (AFC) in the presence of superimposed background noise and to propose an innovative architecture for the joint acoustic feedback path estimation and noise reduction (NR), whose effectiveness is proved by experimental results. The proposed architecture is an evolution of a scheme already known as PEM-AFROW, which is based on a particular implementation of the Prediction Error Method for an unbiased estimation of the acoustic echo path. The objective of the contribution is to properly extend the applicability of such a technique to the more general case of noise presence, whose effects should be likely minimized to improve speech rendering quality. On purpose, a noise reduction stage based on the MMSE-LSA estimation has been implemented within the closed- loop system, keeping the on-line processing characteristics of the framework.