1. A tone placed in a particular position on a sound track in post-production in order to establish a sync point. The tone is used to align the audio track with the picture for precise synchronization. A fool proof method that is often used as a backup even when time code is being used. For example, your composer might give you audio tracks and place a beep two seconds prior to the start of picture so you can line up the music with your project. 2. Sound made by the Roadrunner.