The document discusses different types of sound that can be used in films, including diegetic sound that comes from within the scene and non-diegetic sound added in post-production. It provides examples of diegetic sounds like dialogue and ambient noise, and non-diegetic sounds like music soundtracks. Musical techniques are also summarized, such as crescendos that build suspense, diminuendos where music fades out, and sforzandos using sharp noises to create shock or fear. Examples are given from films like Jaws, Psycho, and Paranormal Activity to illustrate how these different types of sounds are used.