This document discusses different types of audio codes used in films including dialogue, music, and sound effects. It defines diegetic sound as sound that is part of the film world, while non-diegetic sound has been edited in, such as background music. Parallel sound mirrors the mood of a scene, while contrapuntal sound creates tension by not fitting the scene. Off-screen sounds are used to move the narrative forward, such as investigating a distant scream in the woods at night.