An adaptive noise canceller with adaptive delay compensation for a distant noise source

This paper proposes a noise canceller with adaptive delay compensation for a distant noise source. A delay element is introduced in the noise path to offset the delay caused by the distance from the distant noise source to the reference microphone. To cope with a variety of the distance, it is controlled based on the significance of adaptive-filter coefficients. The delay is increased when the coefficients in the head are more significant than those in the tail, and vice versa. This adaptive control makes the adaptive filter with a limited number of coefficients cover the most significant part of the impulse response of the noise path, thereby achieving the best possible noise cancellation. Simulation results demonstrate superior identification capability, that leads to noise cancellation as good as that with the true amount of delay.