This document defines and distinguishes between diegetic and non-diegetic sound. Diegetic sounds have a visible source in the film, such as dialogue, weather sounds, vehicles or weapons. Non-diegetic sounds do not have a visible source and include score music, narration (if the narrator is not a character), and canned laughter. Examples are provided of films that use only diegetic sounds or remove diegetic dialogue to focus the viewer. The document instructs the reader to analyze the use of diegetic and non-diegetic sounds in the Ender's Game trailer and discuss how other films have used these sounds uniquely.