Foley

In practice

Foley is the craft of recording everyday sound effects in sync with a finished film, performed live by artists watching the picture. Footsteps, the rustle of a coat, a cup set down, keys in a lock, a punch: most of the small sounds you hear in a movie were not recorded on set but made later on a Foley stage by someone matching every movement on screen.

It is named after Jack Foley, a sound man at Universal Studios who began adding live effects to early sound films in the late 1920s, starting with the 1929 Show Boat. His method, performing sounds while watching the projected film, is still the method today, although the projector has become a screen and the tape a digital recorder.

Foley exists because production sound is built to capture dialogue. Microphones on set are aimed at the actors' mouths, so footsteps and cloth come out thin or missing, and they are often cleaned away with the noise. Foley also makes the international version possible: when the dialogue is removed for dubbing, the Foley track keeps every footstep and door in place.

Sound written so a Foley artist can hear it

Nothing in this scene needs a sound effect cue in capitals, but every action line gives the sound team something to perform: the scrape and miss of the key, the hinge that stops, wet sneakers on a hard floor, ticking that grows. A writer who describes what the audience hears, as specifically as what it sees, writes a scene the Foley stage can bring to life.

How Foley sound is made

A Foley stage is a recording room full of surfaces and junk. The floor has pits of gravel, sand, concrete, wood, tile and water, and the shelves hold shoes, doors, chains, bags of cornstarch and boxes of props. Two or three Foley artists, sometimes called Foley walkers, watch the scene on a screen and perform its sounds in time while a mixer records them.

The work is usually split into three passes. Feet are the footsteps of every character, matched to their shoes and the floor. Moves are the cloth and body sounds, the swish of a jacket or the creak of a leather belt. Specifics are everything else: props handled, objects dropped, doors, punches and falls.

The tricks are famous because they work. Snapped celery sounds like breaking bone. Cornstarch squeezed in a leather pouch sounds like footsteps in snow. Coconut shells clapped on a tray make horse hooves, a trick from radio drama. A wet chamois slapped on a table can be a body hitting the floor. The goal is never accuracy but what sounds right to the audience.

Foley examples you have heard

In almost every film, the footsteps are Foley. Next time you watch a scene of two people walking and talking, listen to the steps: they are crisp, even and matched to each actor's shoes, which almost never happens with set audio.

Animation is all Foley and effects, because nothing was recorded on set. Every swish, bump and footstep in a Pixar film was performed or designed afterward. Action films lean on it for fights: a punch on screen is usually a combination of Foley artists hitting leather, meat or cabbage, layered with designed effects.

Horror relies on it for the sounds the audience fears most, close and quiet: a floorboard, breath, a door handle turning. In A Quiet Place (2018), where characters must stay silent, the sound team built much of the tension from small Foley sounds that would be lost in a louder film.

Foley vs. sound effects vs. ADR

Foley is sound performed in sync with the picture by a person. Sound effects, sometimes called hard effects, are sounds cut in from a library or designed in an edit suite: explosions, car engines, gunshots, alien weapons. A big action scene uses both. The car engine is an effect; the driver's hands on the steering wheel are Foley.

ADR, automated dialogue replacement, is the same idea applied to voices: actors re-record their lines in a studio to replace set dialogue that was noisy or needs changing. Foley artists and ADR are both part of post-production, and both are why a finished film sounds cleaner than any real place.

Sound design is the broader craft that shapes all of it. A sound designer decides what a world sounds like, then Foley, effects, dialogue and music are mixed into one track.

How to write sound in a screenplay

Write the sounds that matter to the story, in plain action lines: "A floorboard creaks upstairs." Older screenplays capitalized important sounds ("a GUNSHOT") to flag them for the sound department, and some writers still do for key moments. Use capitals sparingly; a page full of them reads as shouting.

Specific beats generic. "Footsteps" tells a reader little; "bare feet slapping wet tile" tells them who, where and how fast. When a sound replaces an image, such as a scream heard from another room or a car door outside, it can carry a reveal or a scare on its own, and it will be cheaper to shoot than to show.