Film & TV

Diegetic Sound and Non-Diegetic Sound: What’s the Difference?

Written by MasterClass

Apr 23, 2019 • 2 min read

Diegetic and non-diegetic sounds are what make up the sound design for a Hollywood film—from the sound of a car honking onscreen to the lush orchestral melody playing over the closing credits. Below we break down the differences between diegetic and non-diegetic sound in a film.


What Is Diegetic Sound?

Diegetic sound is any sound that emanates from the storyworld of the film. The term comes from the word diegesis, which is the evolution of a Greek term that means narration or narrative.

The source of diegetic sound doesn't necessarily need to be seen on screen, as long as the audience understands that it is coming from something within the film.

How Is Diegetic Sound Made?

Just because a diegetic sound emanates from the world of story, doesn’t necessarily mean that it was recorded that day on set. Many diegetic sounds are actually recorded in a studio by sound engineers, making the sounds clearer. For example:

  • The director forgot to shoot a line of dialogue on set, so the actor will re-record that line in the studio in post-production. This is called ADR.
  • A party scene doesn’t sound exciting enough, so the sound editor will punch up the sound of laughter, music, or ambient noise to create a livelier party atmosphere.

3 Examples of Diegetic Sound

  1. Character dialogue is the clearest example of diegetic sound.
  2. Object sounds make a film more realistic. For example, if a character walks in the snow, the audience should hear the crunching of their footsteps. If a character is standing on a busy street, we hear the natural ambiance of the city.
  3. Music emanating from within in the film helps the audience become absorbed in a scene. For example, music playing loudly in someone’s headphones, or the pounding dance music at a bar are also diegetic sound. This kind of diegetic sound is also called “diegetic music” or “source music.”

What Is Non-Diegetic Sound?

Non-diegetic sound, also called commentary or nonliteral sound, is any sound that does not originate from within the film’s world. The film’s characters are not able to hear non-diegetic sound. All non-diegetic sound is added by sound editors in post-production.

3 Examples of Non-Diegetic Sound

  1. The film’s musical score is used to set the film’s tone, manipulate emotions, add drama, express ambiguity, or provide an element of surprise.
  2. Sound effects are added for dramatic effect. For example, a record scratch sound added for comic relief is not heard by the characters in the film.
  3. Narration or voice over is used to help explain or reinforce the plot.

What Is Trans-Diegetic Sound?

When diegetic and non-diegetic sound are combined, it’s called trans-diegetic. Trans-diegetic sound refers to any sound that moves in between non-diegetic and diegetic, or vice versa. Trans-diegetic sound helps bridge or link two things, like transitions between scenes.

2 Examples of Trans-Diegetic Sound and When a Filmmaker Should Use It

  1. A character hums a tune (diegetic sound) and that humming sound turns into an orchestral version of the same tune (non-diegetic sound), which carries over into the next scene.
  2. Music plays over the opening credits of a film (non-diegetic sound), but once the title sequence ends, that same music becomes a song heard on someone’s radio in the opening scene (diegetic sound). This example links the credit sequence with the opening scene to ease the audience into the movie-going experience.