What is diegetic sound?

• A. Music added in postproduction to enhance mood.
• B. Ambient noise from outside the scene.
• C. Sound originating from a source within the scene, such as dialogue.
• D. A soundtrack only the audience hears but characters do not.

Answer: (C)

Diegetic sound is sound that has a source inside the world of the story and is audible to the characters. It grounds the scene in realism because you hear things the characters would actually hear, like dialogue spoken by someone in the room, footsteps, or a radio or television playing within the scene.

So the best description here is sound that originates from a source within the scene, such as dialogue, because that directly captures the idea of a source inside the story world. In contrast, music added after filming to set mood is not coming from within the scene and is heard only by the audience in many cases, making it non-diegetic. A soundtrack that only the audience hears is also non-diegetic. Ambient noise from outside the scene can be confusing—it might be diegetic if it comes from a real in-world source, but the clearest example of diegetic sound is something with a definite in-scene origin like dialogue.