a system and method for automatically adjusting the volume of an audio system to compensate for variations in ambient noise . the system includes a microphone for monitoring the ambient audio environment which includes output of the audio system plus environmental noise . the system also includes processing circuitry connected to the microphone . the processing circuitry varies the volume of the output of the audio system in proportion to changes in the environmental noise . the processing circuitry comprises the microphone , located to detect the ambient sound in the listening environment , an analog - to - digital converter connected to the output of the microphone , and a digital signal processor connected to the output of the analog - to - digital converter . the output signal of the dsp is an input to the volume control of the audio system .