Although you may not actively hear these sounds, if they weren't there you'd wonder what was missing. The process is named for radio and movie sound pioneer Jack Foley, a technician at Universal Studios in the 1950s who became famous for synchronized sound effects. Foley artists begin their work by watching the film to determine which sounds need to be replaced, which need to be enhanced, and which just simply need to be added. At this time, the sound on the film includes all of the dialogue and sound effects created during the actual production of the film. These sounds are recorded on a production track or guide track.
Some sound effects are common and can be pulled from prerecorded audio libraries.
As they watch the film, the artists identify which sounds they need to create and start thinking of ways to make them. In addition to the noises themselves, the foley artists must consider other factors, such as who makes the sound and in what environment. Some sounds are too complex for one take, so the foley artists carefully combine different noises to fully represent a single sound. In some cases, foley editors can digitally alter recorded sounds to fit a scene exactly. In a foley studio, you'll find different surfaces for walking on, a splash tank , echo chambers , and a mixing booth where the sound engineers record and mix everything.