Waveform is a type of sound that works like a tape recording: speak into a computer's microphone, and your voice becomes a waveform sound file (typically stored in WAV, AIFF, or AU format). Waveform sounds play back from disk using sound chips in your computer's system board or on an add-in audio card. System sounds, such as the annoying Windows ding.wav file, and downloadable audio clips are all waveform sounds.