Robust and High Gain Acoustic Feedback Compensation in the Frequency DomainWith a Simple Energy-decay Operator

Acoustic feedback compensation in speech applications often suffers from an insufficient adaptation. As a result feedback whistling may be audible and the compensation gain and generally the speech quality is limited. In this work, we introduce the concept of an energy-decay operator and show how to use it for tap-selective step-size control of a multi-delay frequency-domain filter (MDF). Therefore, we derive a so-called “complex sign-sign algorithm” with an inherently included decay operator. Finally, we show robust simulation results with high amplification although the used algorithm shows very low complexity. Possible applications are in-car communication (ICC) systems or other sound reinforcement applications.