Incorporating first/second ADCs A1/A2 of an ANR circuit, first/second pluralities P1/P2 of digital filters of a quantity specified by first/second sets S1/S2 of ANR settings, and DACs into first/second pathways Pa1/Pa2； selecting a type of digital filter specified by S1 for each digital filter of P1/P2； adopting a signal processing topology specified by S1 by configuring interconnections among at least A1/A2, P1/P2 and the DAC so that digital data representing sounds flows through Pa1 from A1 to the DAC through at least P1； digital data representing sounds flows through Pa2 from A2 to the DAC through at least P2； Pa1/Pa2 are combined at first/second locations along Pa1/Pa2 such that the digital data are combined before flowing to the DAC； configuring each digital filter with filter coefficients specified by S1； setting a data transfer rate at which digital data flows through at least a portion of Pa1/Pa2 as specified by S1； operating A1/A2, P1/P2 and the DAC to provide ANR in the earpiece； changing an ANR setting specified by S1 to one specified by S2 in synchronization with a transfer of digital data along at least a portion of Pa1/Pa2； monitoring a characteristic of a sound represented by digital data； wherein changing an ANR setting occurs in response to a change in the characteristic, changing an interconnection of the signal processing topology defined by S1, a selection of a digital filter specified by S1, a filter coefficient specified by the S1, and a data transfer rate specified by S1.
