When the Track View for audio tracks is set to Waveform, Pro Tools draws a waveform diagram of the audio. Audio waveforms tell you several things about the recorded sound.
In the figure above, the “peaks” represent places in the recording where the attack of the sound causes the volume to increase momentarily. These are followed by “valleys,” where the volume decreases.
Different types of sounds produce different types of waveforms. Drums, for example, generally produce waveforms with sharp
transients (peaks of short duration) that are clearly defined. A drum hit has a loud, sharp attack and a rapid decay.
Other sounds, such as vocals or sustained synthesizer pads, produce very different waveforms. These sounds have less pronounced peaks and valleys because they generally have softer attacks and longer decays.