Sound effects can be recorded in the “field”. A sound recordist ventures outside the studio to record specific sounds needed for a movie at the request of the director or sound supervisor. The library might contain sounds from a specific model of car, but in a particular film, that car might be spinning out in a chase scene or passing by at 80 mph. Those exact sounds will be recreated and recorded on a DAT (digital audio tape) for use in the film, then stored in the library. Gunshots are often recorded in the field to match the exact model of the gun being used in a scene. This is especially true of “period,” or historic movies, where the blast from a Revolutionary War musket might be recorded to get the appropriate sound. Sound supervisors often go to great lengths to get an authentic sound; recently, a Sony sound supervisor made recordings on an aircraft carrier in the middle of an ocean.

Most field recording happens during post-production. However, some sound effects recording takes place during production. The production mixer, who records the sound and dialogue during the shooting of a film, or a sound recordist sent to the location, will also record “wild track.” Wild tracks are sounds recorded on location during the film shoot. These sounds are specific to the movie, such as the roar of a big crowd or the zooming noises of skateboard champions doing tricks, and because of cost or time constraints, would be hard to recreate.