Short description of Auto Volume Control 2.1: Solves the volume control problems for TVs, radio stations, CDs and Public Address systems. Now use your PC as a volume control device which stays between the audio input source (microphone) & the audio output source (speaker) all this software requires is a sound card with a line-in and line-out.No more be startled by obnoxiously loud commercials. Keeps volume levels steady, so you won't be bothered by annoying volume dips or peaks