What does the term "diegetic sound" refer to?

The term "diegetic sound" refers to sound that originates from within the film's narrative world, meaning it is sound that the characters in the film can hear. This includes sounds like dialogue spoken by the characters, sounds made by objects within the film, and music that is part of the scene, such as a band playing in a bar or a radio playing in a character's home. Diegetic sound enhances the realism of the narrative by grounding the audience in the film's world.

The other options represent different concepts. For instance, sound that is added in post-production does not exist in the film's world and is known as non-diegetic sound, which includes background music or narration that the characters cannot hear. Background music specifically is also a form of non-diegetic sound, as it is typically meant to evoke emotions in the audience rather than being part of the characters' experience. Lastly, while the voices of the characters are indeed diegetic, this definition is too narrow, as diegetic sound encompasses a broader range of auditory elements that include more than just dialogues.