The document discusses various types of sound that can be used in films, including diegetic sound whose source is visible or implied, versus non-diegetic sound whose source is neither. It also covers synchronous sound that is matched to the visuals versus asynchronous sound that provides mood. Additionally, it defines voiceovers, flashbacks, sound perspective, bridges, nonsimultaneous sound, direct sound, sound effects, motifs, dialogue, incidental music, themes and stings, and ambient sounds.