Acoustic Feedback Compensation with Reverb-based Stepsize Control for Incar Communication Systems

An acoustic feedback cancellation method with a stepsize controlled frequency domain NLMS algorithm is presented. If the NLMS is used to estimate the feedback path of a closed electro-acoustic loop, its performance is restricted due to correlation of excitation signal and desired signal. By controlling the stepsize of the NLMS algorithm, its convergence can be improved and the system remains stable at high gains. The stepsize control is based on a reverberation model. If the proposed method is applied to speech signals, no further decorrelation methods are necessary. The algorithm is designed for an in-car communication (ICC) system, but it can also be adapted to other audio applications, such as public address systems.