Variable step-size based online acoustic feedback neutralization in multiple-channel ANC systems

This paper investigates the issue of acoustic feedback in multichannel active noise control (ANC) systems. The presence of acoustic feedback degrades the performance of the ANC systems, and in the worst case the ANC system may become unstable. Previously we have proposed a simplified method for acoustic feedback path modeling and neutralization (FBPMN) during the online operation of multichannel ANC systems. The computational complexity of the proposed method is lower than the existing method. Here we introduce an intuition based variable step-size (VSS) parameter, for LMS algorithm of FBPMN filter. This VSS is motivated from the fact that the error signal of FBPMN filter contains a disturbance-component that is decreasing in nature. Computer simulations are carried out for a 1×2×2 system comprising one reference microphone, two secondary loudspeakers and two error microphones. It is demonstrated that the proposed method achieves better performance than the existing method.