Editing Sound effect (section)

== Film ==

In the context of motion pictures and television, ''sound effects'' refers to an entire hierarchy of sound elements, whose production encompasses many different disciplines, including:
* ''Hard sound effects'' are common sounds that appear on screen, such as door alarms, weapons firing, and cars driving by.<ref name=":0">{{Cite journal |last=Schrader |first=Paul |date=1995 |title=Paul Schrader |url=http://dx.doi.org/10.5040/9780571344406.0063 |journal=Projections 4½ |doi=10.5040/9780571344406.0063|isbn=978-0-571-34440-6 }}</ref>
* ''Background'' (or ''BG'') ''sound effects'' are sounds that do not explicitly synchronize with the picture, but indicate setting to the audience, such as forest sounds, the buzzing of fluorescent lights, and car interiors.  The sound of people talking in the background is also considered a ''BG'', but only if the speaker is unintelligible and the language is unrecognizable (this is known as [[walla]]). These background noises are also called ''ambience'' or ''atmos'' ("atmosphere").<ref name=":0" />
* ''Foley sound effects'' are sounds that synchronize on screen, and require the expertise of a [[Foley artist]] to record properly.  Footsteps, the movement of hand props (e.g., a tea cup and saucer), and the rustling of cloth are common Foley units.<ref name=":0" />
* ''Design sound effects'' are sounds that do not normally occur in nature, or are impossible to record in nature.  These sounds are used to suggest futuristic technology in a [[science fiction film]], or are used in a musical fashion to create an emotional mood.<ref name=":0" />

Each of these sound effect categories is specialized, with [[Sound editor (filmmaking)|sound editor]]s known as specialists in an area of sound effects (e.g. a ''Car cutter'' or ''Guns cutter'').

[[Foley (filmmaking)|Foley]] is another method of adding sound effects. [[Foley (filmmaking)|Foley]] is more of a technique for creating sound effects than a type of sound effect, but it is often used for creating the incidental real-world sounds that are very specific to what is going on onscreen, such as footsteps. With this technique, the action onscreen is essentially recreated to try to match it as closely as possible. If done correctly it is very hard for audiences to tell what sounds were added and what sounds were originally recorded (location sound).

In the early days of film and radio, Foley artists would add sounds in real time or pre-recorded sound effects would be played back from analog discs in real time (while watching the picture). Today, with effects held in digital format, it is easy to create any required sequence to be played in any desired timeline.

In the days of silent film, sound effects were added by the operator of a [[theater organ]] or [[photoplayer]], both of which also supplied the soundtrack of the film. Theater organ sound effects are usually electric or electro-pneumatic, and activated by a button pressed with the hand or foot.

Photoplayer operators activate sound effects either by flipping switches on the machine or pulling ''cow-tail'' pull-strings, which hang above. Sounds like bells and drums are made mechanically, sirens and horns electronically. Due to its smaller size, a photoplayer usually has fewer special effects than a theater organ or less complex ones.