This document defines different types of sound that can be used in films. Diegetic sound comes from within the scene, such as dialogue or ambient noise. Non-diegetic sound is added during post-production and includes music soundtracks and effects. A crescendo uses building music or sound to imply something is about to happen, while a diminuendo dies sound down to suggest a threat has passed. A sforzando is a short, sharp loud noise that can emphasize shock or fear.