An output-whitening approach to adaptive active noise cancellation

An approach to adaptive active noise cancellation that is based on adaptive control principles is described. The approach aims at creating a physical noise-reduced environment in the vicinity of noisy machinery, for stochastic machine noise. The system described uses a single microphone, in contrast to previously described two-microphone systems. Computed results on two types of recorded industrial noise are presented to support the theoretical design. In one case, a reduction of the sample variance of noise by a factor of 500, i.e. about 54 dB, occurred; in the second case, a reduction factor of 17, i.e. about 25 dB, was achieved