Using non-diegetic sound is a great way for filmmakers to support the worlds that they build. You may have heard this fancy term before but what is non-diegetic sound? The answer is much less complicated than you think. In this article, we’re going to define what non-diegetic sound is. Then, we’ll look at examples from cinema history that show us how to properly and creatively use it.
Non-diegetic sound explained
In general, sound is the unsung hero of creating an immersive experience for the audience. Since cinema is primarily a visual medium, we might assume that "seeing is believing" but really the final piece in creating a cohesive cinematic experience is what we hear on the soundtrack. Let's define non-diegetic sound before exploring the creative ways filmmakers like Martin Scorsese, Edgar Wright, and Mel Brooks bring just as much to their sounds as they do their visuals.
NON-DIEGETIC SOUND DEFINITION
What is non-diegetic sound?
Non-diegetic sound is any sound in a film that doesn’t originate from the world of the film. These are typically sounds that are added for effect in post-production. For example, a film soundtrack is almost always non-diegetic sound because the characters don’t hear it. The short answer to what is non-diegetic sound is this: If the characters can't hear it, it's non-diegetic.
Examples of Non-Diegetic Sounds
- Character narration
- Soundtrack or music overlay
- Sound effects outside of the film-world
If we imagine a film as an assembly of many pieces made to look whole, diegetic sound and non-diegetic sound work together to add the final layer to that illusion. Without that "glue," we would see the cracks and seams holding it all together. So now that we know what non-diegetic sound is, let’s dive into specific examples.
Of all non-diegetic sound, music takes the largest slice of the pie. A musical score is perhaps the biggest "gamble" for an audience because it's a major element that does NOT belong to the diegesis, aka the world of the film.
Thankfully, after decades of using non-diegetic music in movies, the audience doesn't think about it to much. Let's look at some examples that use non-diegetic music for maximum effect.
Star Wars (1977)
The opening crawl for Star Wars films are great examples of non-diegetic music and text. The John Williams score is an accompaniment, something exclusively for the audience to hear, not the characters.
The text is also non-diegetic because it is a screen overlay. If the text were displayed on a screen within the film-world, it would be diegetic.
Catch Me If You Can (2002)
Non-diegetic music doesn’t have to be orchestral or produced specifically for a film. Popular music is often used on the soundtrack to function the same way a non-diegetic score would be. In this scene from Catch Me If You Can, we hear Frank Sinatra’s Come Fly With Me.
This is an example of non-diegetic sound because it’s not playing from within the film-world. If it was revealed to have been playing in the airport terminal or from a car radio, it would be diegetic. Such is the case with our next example.
Blazing Saddles (1974)
Sometimes, what we first perceive to be non-diegetic music turns out to be diegetic. Usually, this involves a song playing on the soundtrack (non-diegetic) but then a character turns off the radio and the song ends (diegetic). Mel Brooks visualized this transition for comedic effect in Blazing Saddles in a very "Brooks-ian" way.
Music is the most often used element in non-diegetic sound but it's not the only game in town. In the next section, we'll look at how narration is used as part of a non-diegetic soundtrack.
Two Great Examples
The second-most common type of non-diegetic sound is narration. This type of narration is limited to literal narration, not any and every voiceover. For example, Forrest Gump narrates most of the movie but he's actually telling his story to other characters (i.e., diegetic).
Another form of voiceover commonly mistaken as non-diegetic is internal monologue (e.g., when we hear a character's thoughts). Since we are lead to believe that the character is also hearing those thoughts, it is still diegetic sound.
Non-diegetic narration is purely for the audience's benefit. No other characters can hear it and it is not simply a character's thoughts.
Fight Club (1999)
In Fight Club, Edward Norton's character gives us a ton of non-diegetic narration. Whether or not that narration is accurate is the topic for another article. Take a listen.
Norton's character talks us through the fight club that he and Tyler have started, filling in the gaps of what we see on-screen. If you've seen the film, you know how important Norton's voiceover and point-of-view are to the story, making this use of non-diegetic narration essential.
American Psycho (2000)
American Psycho is a film that aims to connect the audience with the protagonist Patrick Bateman. One way the film does this is by allowing Bateman (Christian Bale) to speak directly to the audience.
This is done through character narration. Since the viewer is obviously an inactive participant of the film-world, this narration is non-diegetic. This works extremely well in this film as it gives us an inside look inside the mind of a psychopath.
Just like the difference between diegetic and non-diegetic music, narration can transition back and forth between the two categories. Martin Scorsese does this all the time in films like The Wolf of Wall Street but there's probably no better example than Goodfellas.
Henry Hill has been our primary narrator, spinning non-diegetic yarns for over 2 hours when this happens:
The moment Henry addresses the camera directly is an abrupt and shocking switch between non-diegetic and diegetic narration. It also happens to be a great example of breaking the 4th wall, shattering the illusion completely. Are we lead to believe that Henry's narration up to this point was all part of his testimony? If so, it's an extremely creative way for Scorsese to play with our expectations of non-diegetic sound.
Outside The World
Non-diegetic sound effects
Sound effects are almost always diegetic but in rare instances they can also be part of the non-diegetic sound design. These are often used for comic relief or in exaggerated ways that are clearly meant to be identified by the audience as non-diegetic.
Let's look at a couple of examples.
Shaun of the Dead (2004)
Using quick cuts and exaggerated sound effects (particularly in montages) is something of an Edgar Wright staple. Listen as Shaun reviews their various plans and how non-diegetic sound effects play a major role in how this mini-montage is constructed.
Wright uses a lot of "whooshes," especially alongside whip pans, in this clip. There's also that great rumble and clang as Shaun and Ed bring their weapons together once they've settled on a plan. Together all of the sounds become a textbook example of non-diegetic sound effects.
Kill Bill Vol. 1 (2003)
What is non-diegetic sound? Just ask Tarantino, who has a lot of fun mixing diegetic and non-diegetic sound effects into his films. Take this showdown between The Bride and Gogo. There are plenty of diegetic sound effects (e.g., the swoosh as Gogo swings her weapon) but there are also plenty of non-diegetic examples mixed in.
How filmmakers use diegetic sound
What is non-diegetic sound? We've answered that question and it leads us straight to understanding its opposite. Let’s look at some examples of diegetic sound, including dialogue, music and sound effects from movies like Mad Max: Fury Road.