What type of sound is produced when a character narrates a film that only the audience can hear?

The sound produced when a character narrates a film that only the audience can hear is classified as non-diegetic sound. This type of sound exists outside the narrative space of the film; it is not part of the world that the characters inhabit, and they cannot hear it. Non-diegetic elements, like a character's narration that provides internal thoughts or context for the viewer, serve to enhance the storytelling and emotional resonance of the film without being acknowledged by the characters in the scene.

Diegetic sound, in contrast, refers to sounds that are naturally part of the film's world, such as dialogue, sound effects, and music that the characters can hear. Ambient sounds are background noises that establish the setting, while Foley refers to the reproduction of everyday sound effects that are recorded and added in post-production to enhance audio quality. The use of non-diegetic narration is a powerful cinematic tool that allows filmmakers to share insights with the audience, influencing their understanding and emotional experience without being perceived directly by the characters.