One method of processing microphone input in an ADC to determine microphone configuration is to process the microphone input signals in two processing paths, in which one processing path processes a difference between differential input signals and another processing path processes an average value of the differential input signals. The outputs of these processing paths may be combined to generate a digital signal representative of the analog signal from the microphone. The digital signal contains a digital version of the audio in the environment around the microphone, but may also be used to detect microphone topology and configure aspects of the processing paths to match the detected microphone topology. An apparatus for an ADC may implement the two processing paths as two delta-sigma modulator loops.