An acoustic noise reduction audio system having tap control, comprising: a power supply arranged for providing a supply current ( I S) which is separated, at a node, into a first supply current ( I 1) and a second supply current ( I 2); an ANR module comprising: an ANR engine comprising a first ANR engine input to receive an audio input signal, a second ANR engine input to receive the first supply current ( I 1) from the power supply through a first electrical path, and an ANR engine output to provide an audio output signal; and an acoustic driver amplifier having a first driver amplifier input to receive the second supply current ( I 2) from the power supply through a second electrical path, a second driver amplifier input in communication with the ANR engine output to receive the audio output signal and a driver amplifier output to provide an amplified audio output signal; a current sensor disposed in the second electrical path and having a sensor output to provide a signal responsive to a characteristic of the second supply current; a signal conditioner module having an input in communication with the sensor output and having a signal conditioner output, the signal conditioner module providing a conditioned signal at the signal conditioner output in response to the signal responsive to the characteristic of the second supply current; and an audio and mode control module having a first input to receive a source audio signal, a second input in communication with the signal conditioner output, and an output in communication with the first ANR engine input, the audio and mode control module controlling at least one of a mode of operation of a headphone system and an attribute of the audio input signal in response to the conditioned signal. a power supply arranged for providing a supply current ( I S) which is separated, at a node, into a first supply current ( I 1) and a second supply current ( I 2); an ANR module comprising: an ANR engine comprising a first ANR engine input to receive an audio input signal, a second ANR engine input to receive the first supply current ( I 1) from the power supply through a first electrical path, and an ANR engine output to provide an audio output signal; and an acoustic driver amplifier having a first driver amplifier input to receive the second supply current ( I 2) from the power supply through a second electrical path, a second driver amplifier input in communication with the ANR engine output to receive the audio output signal and a driver amplifier output to provide an amplified audio output signal; an ANR engine comprising a first ANR engine input to receive an audio input signal, a second ANR engine input to receive the first supply current ( I 1) from the power supply through a first electrical path, and an ANR engine output to provide an audio output signal; and an acoustic driver amplifier having a first driver amplifier input to receive the second supply current ( I 2) from the power supply through a second electrical path, a second driver amplifier input in communication with the ANR engine output to receive the audio output signal and a driver amplifier output to provide an amplified audio output signal; a current sensor disposed in the second electrical path and having a sensor output to provide a signal responsive to a characteristic of the second supply current; a signal conditioner module having an input in communication with the sensor output and having a signal conditioner output, the signal conditioner module providing a conditioned signal at the signal conditioner output in response to the signal responsive to the characteristic of the second supply current; and an audio and mode control module having a first input to receive a source audio signal, a second input in communication with the signal conditioner output, and an output in communication with the first ANR engine input, the audio and mode control module controlling at least one of a mode of operation of a headphone system and an attribute of the audio input signal in response to the conditioned signal.