What are Diegetic & Non-Diegetic Sound in Film? Definition & Examples

Published: December 3, 2019 | Last Updated: November 22, 2024

Let’s break it down in more detail below and look at movie examples.

Diegetic and non-diegetic sound design in movies

Diegetic sound (or music) originates from within the film’s narrative.

If a gangster fires a gun, the sound of that gun is diegetic (also if the sound is a sound effect, which is added in post-production). The point is that the sound of the gun originates from within the film’s story.

Likewise, it is considered diegetic music when the pianist Sam – “Play it again, Sam” – plays As Time Goes By at the bar in the movie Casablanca (1942).

However, when you hear John Williams’s score of The Empirical March in Star Wars, it is not part of the narrative and thus non-diegetic (aka. extra-diegetic).

If Darth Vader had blasted The Imperial March from the speakers of a boombox at the bridge of the Death Star, the composition would have been part of the film’s diegesis, and thus diegetic sound instead.

If you want to go all academic rabbit whole, you can also distinguish between extra- and non-diegetic sounds, but it’s beyond the scope of this article. For the sake of clarity, I’ll use these two terms interchangeably. The essential thing to understand is that extra/non-diegetic sounds and music are not a natural part of the film’s narrative but something extra—a sonic context—for the film.

On-Screen Sounds and Off-Screen sounds.

Like characters and objects, diegetic sound can be placed on-screen and off-screen, i.e., inside or outside each frame in the film. Effective use of off-screen sounds is a great way to make each frame – or the screen – seem more significant than it is.

For example, you might show the character in your short film walking down a dark country road when you hear the sound of a car approaching from outside the frame. In this case, the car’s sound is diegetic off-screen. But as soon as the car enters the frame and stops next to your protagonist, the sound is transformed from diegetic off-screen to diegetic on-screen. Likewise, if the car drives from on-screen to off-screen, the sound transforms from an on-screen diegetic sound to an off-screen diegetic sound.

Your typical extra-diegetic sound score is always off-screen, as it isn’t part of the diegesis.

Likewise, if you do a voice-over for a documentary, animated explainer video, or commercial, the voice-over is also extra-diegetic off-screen.

Below, I’ve created a small table with a couple of typical examples of the different types of sound found in each type. Remember that sounds can easily jump from one cell to another as the framing shifts in a scene.

Relationship to Story/Screen	On-Screen	Off-Screen
Diegetic	Dialogue SFX made by narrative objects (fx gunshots, tea kettle, car tires, footsteps) Music (fx from a piano/boombox/discoteque in the film)	Voice-over (fx the voice as the protagonist acting as a narrator’s voice) SFX (fx creaking floorboards in a horror movie, walla)
Extra-Diegetic	SFX added for dramatic effect, but not emanating from a specific object in the story (fx a stinger or ‘boom’ sound effect when a spaceship flies across the screen in a sci-fi movie)	Film Score (fx mood music, soundtrack music with popular music tracks) Voice-over (fx documentary film narrator, explainer video)

Why Should I Care About Diegetic and Extra-Diegetic Sounds?

You can use these terms to analyze what other sound designers have done. That way, you can develop a better understanding of sound in film. So, even though you might usually add sounds that fit on the go, being extra aware of how your sounds relate to the story and frame can help you create a better sound design for your movie.

For example, you can introduce objects from off-screen to on-screen to create a more coherent world: if a car is approaching from off-screen, you can use a J-cut to fade in the car sound to the loudness level of when we finally see it on-screen. Likewise, you can use an L-cut when it drives from on-screen to off-screen.

Second, you can use off-screen ambiance sounds or walla to create a much larger 3D space than what is seen on screen for a much more immersive experience. Is your protagonist sitting in an apartment in a busy city? Make sure to include some city background noise to give the viewer a sense of the city. Ask yourself whether it is a small-scale town or a big metropolis. Is it a dangerous city (maybe add some sirens)?

If you’re mixing in surround sound, using diegetic off-screen sounds gives you many opportunities to provide the viewer with extra information about the depth and direction of diegetic objects and characters in a scene.

Analyzing Horror Films is a Great Way to Learn About Sound Effects

Also, if you’re shooting a horror short, using diegetic off-screen sounds is a great way to create suspense. The horror genre often excels at this because sound can convey so much information to the viewer.

In most horror film subgenres, you don’t want to give away everything about the big monster in the end. Visually, you might reveal scaled skin, sharp teeth, or a knife. – Or you might choose to reveal nothing visual at all.

In that case, using off-screen diegetic sounds is your friend, as you can build a sense of horror from creaking floorboards, howling in the distance, and so much more. You can also give a sense of the beast’s size, e.g., create a bigger monster by adding more bass frequencies to footsteps.

A diegetic omnipotent and ubiquitous character, consequently placed off-screen and only revealed through sound effects, is called l’acousemêtre (a term coined by film researcher Michel Chion in his excellent book Audio-Vison: Sound on Screen).

You can always reveal the big scary monster in the end with a diegetic on-screen scary sound and maybe an extra-diegetic on-screen stinger to make that jump scary extra efficient.

Diegetic and non-diegetic sound movie examples and analysis

So, let’s break down a couple of interesting examples so you can understand how analyzing the sound using diegetic and extra-diegetic sounds can help you stress the points you want to make as an instructor or sound designer.

First example: The Truman Show

The first example is from the movie The Truman Show (1998) starring Jim Carrey.

Have a look at this clip:

Listen to the music composed by Philip Glass. You might think this is just your typical extra-diegetic off-screen film score, and it seems to start this way. However, as the camera shows more of the control room with Ed Harris, we see that it is, in fact, Philip Glass himself who sits at the piano and plays while Truman sleeps. The track is called ‘Truman Sleeps,’ by the way.

In the scene, we are taken from the diegesis of the TV program “The Truman Show,” which is what is available to the fictional viewers in the movie, to the control room, where Christof (Ed Harris) has the power to “play God” and manipulate the characters in the show.

We are given a “behind the scenes” look at the show and the transformation of the music from extra-diegetic off-screen sound to diegetic on-screen sound. The director, Peter Weir, stresses that we, as viewers, are given a sense of power.

It’s a powerful position that isn’t available to the show’s viewers, especially not to Truman, who is unaware of the setup. Also, being let into the control room and seeing the film score being made helps stress the film’s big themes: If there is a God, we’re all just puppets constantly manipulated (e.g., by soothing piano sounds). Nothing is random, but a higher deity controls everything we cannot see nor reach.

Then there’s the whole question: what is the reality, and what is fake?

One reality seems natural to Truman, and one to the viewers of the Truman reality show in the movie. Then there’s us as viewers, the reality of Christof (the almighty producer), and then there’s the reality of us – the viewers – watching all of these realities unfold in the movie. We are effectively taken through these different realities by transforming the music from off-screen extra-diegetic to on-screen diegetic.

There are many other themes in this excellent movie, and the sound design does a good job of reflecting these, but to keep this article short, I’ll let you explore more of them.

Second Example: Ferris Bueller’s Day Off (1986) – Opening Scene

The scene starts with the off-screen diegetic voices of Ferris Bueller’s mother and father. First, we hear the mother over the title—even before we get to the first establishing shot, where we also hear the father’s voice. Then, we cut to a close-up shot of Ferris while we still hear his parents’ voices. We still haven’t seen the parents, so they’re diegetic off-screen. After this, we finally get to see them.

Already, you get the sense that the parents are in the background, not in control, which is true for the rest of the movie.

Cut to around 2:33, when Ferris tricked his parents into believing he was ill. The parents leave the room, and suddenly, Ferris Bueller (Matthew Broderick) turns his head and addresses the audience directly with a, “They bought it!”

By breaking the fourth wall in this way, as Ferris does many times during the movie, his voice suddenly breaks the walls of the diegesis. It goes from being the on-screen diegetic voice of our protagonist to being a sort of meta commentator on the diegesis. This elevates Ferris to a position of power, which seems to extend beyond the diegesis. For example, this protagonist narrator reveals a lot about his friend Cameron’s difficulties.

It is also interesting to note that whenever Ferris is in the diegesis, he lies, steals, and skives school, but when he addresses the audience, he is always honest and sincere. It’s as if this omnipotent role uplifts his character’s morale to that of God, i.e., the voice of the Father, who always speaks the truth.

Conclusion

I know making videos and films is a very hands-on craft. But that doesn’t mean you should neglect academic tools and terms, which often offer something unique when understanding a movie’s essential building blocks.

In this case, the building blocks are the many different ways sound design can stress essential elements in your film. Knowing how to analyze and utilize diegetic and extra-diegetic sound and music can help you raise awareness of your soundscape and create better sound design throughout your film. And bad sound is one of the major reasons films don’t get accepted at film festivals.

It can also help you better stress essential aspects of your movie by asking yourself: “WHY do I want a sound here, and WHAT should that sound be?”

Up Next: Royalty-free sound effects