Keep Listening: How a Movie Soundtrack Is Made
By Steve Lee for The Hollywood Sound Museum
Hi everyone, and thanks for checking out my work.
My name is Steve Lee. I was born and raised in Los Angeles, and I’ve spent almost 40 years working in motion picture sound.
Many of the articles collected here will be about the history of film sound and the people who created it. A number of them were originally published in Wavelength, the magazine of the Motion Picture Sound Editors.
Since these articles were originally written for an audience that already knew something about the business, they can occasionally get a little “inside baseball.” So before getting into the history, I thought it might be useful to explain, in fairly simple terms, how a movie soundtrack is actually made.
Production Sound
The process begins while the movie is being shot.
On the set, the production sound mixer and their crew are responsible for recording the actors’ dialogue as cleanly as possible.
When circumstances allow, the production sound crew may also record additional sounds from the location. These are often called wild tracks or wild sound because they are recorded separately and are not synchronized to a particular camera take.
The production recordings are sent along with the picture to the editorial department, where the picture editor uses them while assembling the film.
Post-Production Sound
As the movie approaches what is known as picture lock — the point at which the picture editing is essentially finished — the sound department begins preparing the soundtrack in earnest.
Like medicine, motion picture sound is really a collection of specialized disciplines. Everyone is working toward the same goal, but the skills involved can be remarkably different.
Depending on the production, these jobs may be performed by large specialized crews or by just a few people wearing several hats, but the basic elements of the work remain much the same.
The supervising sound editor will usually watch the film with the director and other members of the creative team in what is called a spotting session. They discuss what the soundtrack will need: which sounds already exist, which need to be found, which need to be recorded, and which may have to be created from scratch.
Sound Effects & Ambiences
Sound editors search their own libraries and other collections for appropriate material. Sound effects recordists may be sent out into the world to capture sounds specifically for the film: cars, aircraft, machinery, animals, weapons, doors, crowds, or environments.
Editors also build the backgrounds, or ambiences, that create the sonic environment of each scene. A city street, for example, might include traffic, distant horns, footsteps, wind, or dozens of subtle layers. Most of these never consciously attract the audience’s attention, but together they help create the sense that the world on screen extends far beyond the edges of the frame.
Sound Design
Sound designers are asked to create things that don’t exist in the real world. They combine, alter, and manipulate recordings to invent sounds for creatures, futuristic machines, spacecraft, or imaginary environments.
Foley
Foley artists are recorded performing sound effects in sync to picture, such as footsteps, cloth and prop movement, and other sound effects that would be difficult to edit individually. Imagine having to edit every single footstep a character makes! It’s best if these are performed in sync to the actors, which creates a more realistic and indigenous performance.
The process is named for pioneering sound artist Jack Foley, who helped develop and perfect the craft.
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People sometimes assume that Foley artists create all of a film’s sound effects, probably because Foley is one of the most visual and frequently demonstrated parts of the craft. But consider a spaceship landing, a dinosaur attack, or an enormous explosion. Clearly, there is more than one way to build a sound.
Dialogue & ADR
Dialogue editors work with the original production recordings, choosing and cleaning up the best available tracks. When location dialogue cannot be satisfactorily repaired — often due to background noise or technical issues — actors are brought into a studio to re-record their lines in a process called ADR (Automated Dialogue Replacement).
Music
While the sound team is at work, the music department is building another essential part of the soundtrack. The composer writes the original score, which is then recorded and edited to fit the picture. The music editor works closely with the composer and filmmakers to help shape how the score works within the film.
Other music may also be selected or licensed, including songs and source music — music that originates within the scene itself, such as something playing on a radio, in a car, or in a club.
Animation
The process is somewhat different for an animated film, although most of the same jobs still have to be done. Dialogue is generally recorded first, and the animation is created to match those performances. From there, the sound team has to build the entire sonic world from the ground up. There is no production track containing incidental sounds from a physical set, because there was no set.
You don’t get anything for free in animation. Every footstep, door, vehicle, prop, background, and creature has to be deliberately created, recorded, selected, and placed. In that sense, an animated soundtrack is one of the purest examples of the sound editor’s craft: everything you hear was put there intentionally.
The Mix
Once all of these elements — dialogue, effects, Foley, and music — have been edited and synchronized to the picture, they are brought to a mixing stage, traditionally called a dub stage.
The enormous number of individual tracks may first be organized and combined during a process called predubbing. Dialogue, groups of sound effects, Foley, and backgrounds are each premixed individually, then brought — along with the music — to the re-recording mixers for the final mix.
This is where the filmmakers make the final creative decisions about the soundtrack: what should be loud or quiet, what should be heard clearly, what should remain subtle, and sometimes what should not be heard at all.
The result is the final soundtrack you hear in the theater or at home.
Craft Over Tools
The tools used to create all of this have changed dramatically over the years. For much of film history, sound editors physically worked with magnetic film, cutting and assembling tracks by hand. Today, virtually all of this work is done digitally, using computers and specialized software.
The technology continues to evolve so quickly that I generally don’t spend much time discussing particular tools in these articles. I’m much more interested in the craft and technique — because while the equipment changes constantly, the fundamental art of creating a soundtrack has changed surprisingly little.
The tools change. The job is still to find the right sound and put it in the right place.
Listening Closely
The next time you watch a movie, particularly during a busy sequence, try listening to the soundtrack as a whole. There may be dialogue, footsteps, vehicles, crowds, backgrounds, individual sound effects, and music all happening at once. Yet somehow you can usually understand what is important and know where your attention should be. That isn’t an accident. Each of those sounds has been chosen, placed, and balanced to help tell the story.
And sometimes the best sound work is the work you never consciously notice. If a scene feels completely natural, you probably aren’t thinking about the footsteps, the traffic outside the window, or the sound of a character setting down a coffee cup. But somebody thought very carefully about every single one of them.
Of course, I’ve simplified the process considerably. A supervising sound editor may spend weeks or months researching and tracking down obscure historical recordings. Recordists may travel halfway across the world to capture a particular sound. Sound designers can spend months developing a single family of sounds.
For Jurassic Park, for example, Gary Rydstrom and his team created convincing dinosaur voices by combining and manipulating recordings of very real animals. The audience heard creatures that had been extinct for millions of years, but the raw ingredients came from animals that are still very much with us.
There is also an entire additional process involved in preparing films for international release. Among the materials normally created is an M&E (Music and Effects) — a version containing music and effects but without the original dialogue. This allows dialogue in other languages to be dubbed in while preserving the rest of the soundtrack.
And even all of that only scratches the surface.
Now, when the articles that follow mention a sound editor digging through an archive, a recordist going out into the field, or a sound designer crafting something brand new, you’ll have a clear picture of where it all fits.
With that bit of groundwork out of the way, let’s get to the stories.
Thanks again for checking out my collection.
Keep listening.
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AI Assistance Disclosure: AI tools may have been used during the editorial process for research assistance, fact-checking, grammar, punctuation, and suggestions regarding wording and structure. All material was reviewed and approved by the author, who takes responsibility for the final text.
