Audio channel is the signal that is produced by a source of sound. It’s easier than it sounds (yeah, I know… pun). Think of a person speaking. The audio signal is the depiction of the sound produced by the person speaking. It’s the sound wave that we see when we record our voices. Go on, download an app and record yourself. Be crazy and creative. The audio signal is the representation or all those sorts of sounds you are making. See audio track for more.