Wide-area adaptive active noise cancellation

This paper describes an adaptive active noise cancellation (ANC) system that is based on an output-whitening approach and is an extension of the work of Graupe and Efron on single point adaptive ANC. The controller works by continually estimating the time-series parameters of the noise to be cancelled and by forcing the cancellation network to follow the identified parameters, so that the output is whitened. To address the problem of wide-area cancellation, a system that consists of a weighted array of single point output-whitening cancellation systems is proposed. Each controller is chosen to cancel the local temporal effects of the noise, and the array weights are chosen to match the wavefront shape. A comparison of cancellations based on single-point and wide-area systems demonstrates the superiority of the wide-area system