A digital active noise cancellation circuit device (330) includes an oversampled, sigma-delta, A/D converter (204), a digital decimation filter (208), a digital intermediate filter (308), a digital interpolation filter (232), and a sigma-delta, D/A converter (252). The device (330) is operative to perform the steps of: receiving (904) the analog noise signal (64), converting (908) the analog noise signal into a digital noise signal (261)； transferring (912) the digital noise signal to a digital decimation filter, selectively bypassing (916) at least a portion of the digital decimation filter by transferring the digital noise signal to a digital intermediate filter (304), processing (920) the digital noise signal in the digital intermediate filter to generate a digital anti-noise signal (316), transferring (1010) the digital anti-noise signal into a digital interpolation filter (232) operable to up-sample the digital anti-noise signal, selectively bypassing (1020) at least a portion of the digital interpolation filter and converting (1030) the digital anti-noise signal into an analog anti-noise signal (68).
