Sound effect


Various acoustic devices in a Greek radio studio
Deep, pulsating digital sound effect
Voice saying "Ja", followed by the same recording with a massive digital reverb
A blackbird singing, followed by the same recording with the blackbird singing with 5 voices


A live rooster in the Yle recording studio in 1930s Finland

The term sound effect ranges back to the early days of radio. In its Year Book 1931 the BBC published a major article about "The Use of Sound Effects". It considers sounds effect deeply linked with broadcasting and states: "It would be a great mistake to think of them as anologous to punctuation marks and accents in print. They should never be inserted into a programme already existing. The author of a broadcast play or broadcast construction ought to have used Sound Effects as bricks with which to build, treating them as of equal value with speech and music." It lists six "totally different primary genres of Sound Effect":

  • Realistic, confirmatory effect
  • Realistic, evocative effect
  • Symbolic, evocative effect
  • Conventionalised effect
  • Impressionistic effect
  • Music as an effect

According to the author, "It is axiomatic that every Sound Effect, to whatever category it belongs, must register in the listener's mind instantaneously. If it fails to do so its presence could not be justified."[1]



  • Hard sound effects are common sounds that appear on screen, such as door alarms, weapons firing, and cars driving by.
  • 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.




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 less special effects than a theater organ, or less complex ones.

Video gamesEdit





Some pieces of music use sound effects that are made by a musical instrument or by other means. An early example is the 18th century Toy Symphony. Richard Wagner in the opera Das Rheingold (1869) lets a choir of anvils introduce the scene of the dwarfs who have to work in the mines, similar to the introduction of the dwarfs in the 1937 Disney movie Snow White. Klaus Doldingers soundtrack for the 1981 movie Das Boot includes a title score with a sonar sound to reflect the U-boat setting. John Barry integrated into the title song of Moonraker (1979) a sound representing the beep of a Sputnik like satellite.


A man recording the sound of a saw in the 1930s

The most realistic sound effects may originate from original sources; the closest sound to machine-gun fire could be an original recording of actual machine guns.

Despite this, real life and actual practice do not always coincide with theory. When recordings of real life do not sound realistic on playback, Foley and f/x are used to create more convincing sounds. For example, the realistic sound of bacon frying can be the crumpling of cellophane, while rain may be recorded as salt falling on a piece of tinfoil.

Less realistic sound effects are digitally synthesized or sampled and sequenced (the same recording played repeatedly using a sequencer). When the producer or content creator demands high-fidelity sound effects, the sound editor usually must augment his available library with new sound effects recorded in the field.

When the required sound effect is of a small subject, such as scissors cutting, cloth ripping, or footsteps, the sound effect is best recorded in a studio, under controlled conditions a process known as foley. Many sound effects cannot be recorded in a studio, such as explosions, gunfire, and automobile or aircraft maneuvers. These effects must be recorded by a professional audio engineer.




Having all of these tracks at once gives a sound designer or audio engineer a great deal of control over how he wants the car to sound. In order to make the car more ominous or low, he can mix in more of the tailpipe recording; if he wants the car to sound like it is running full throttle, he can mix in more of the engine recording and reduce the interior perspective. In cartoons, a pencil being dragged down a washboard may be used to simulate the sound of a sputtering engine.

What is considered today to be the first recorded sound effect was of Big Ben striking 10:30, 10:45, and 11:00. It was recorded on a brown wax cylinder by technicians at Edison House in London on July 16, 1890. This recording is currently in the public domain.

Processing effectsEdit

As the car example demonstrates, the ability to make multiple simultaneous recordings of the same subject—through the use of several DAT or multitrack recorders—has made sound recording into a sophisticated craft. The sound effect can be shaped by the sound editor or sound designer, not just for realism, but for emotional effect.

Once the sound effects are recorded or captured, they are usually loaded into a computer integrated with an audio non-linear editing system. This allows a sound editor or sound designer to heavily manipulate a sound to meet his or her needs.

The most common sound design tool is the use of layering to create a new, interesting sound out of two or three old, average sounds. For example, the sound of a bullet impact into a pig carcass may be mixed with the sound of a melon being gouged to add to the "stickiness" or "gore" of the effect. If the effect is featured in a close-up, the designer may also add an "impact sweetener" from his or her library. The sweetener may simply be the sound of a hammer pounding hardwood, equalized so that only the low-end can be heard. The low end gives the three sounds together added weight, so that the audience actually "feels" the weight of the bullet hit the victim.

If the victim is the villain, and his death is climactic, the sound designer may add reverb to the impact, in order to enhance the dramatic beat. And then, as the victim falls over in slow motion, the sound editor may add the sound of a broom whooshing by a microphone, pitch-shifted down and time-expanded to further emphasize the death. If the film is science-fiction, the designer may phaser the "whoosh" to give it a more sci-fi feel. (For a list of many sound effects processes available to a sound designer, see the bottom of this article.)







  • equalization – different frequency bands are attenuated or boosted to produce desired spectral characteristics. Moderate use of equalization (often abbreviated as "EQ") can be used to "fine-tune" the tone quality of a recording; extreme use of equalization, such as heavily cutting a certain frequency can create more unusual effects.
  • overdrive effects such as the use of a fuzz box can be used to produce distorted sounds, such as for imitating robotic voices or to simulate distorted radiotelephone traffic (e.g., the radio chatter between starfighter pilots in the science fiction film Star Wars). The most basic overdrive effect involves clipping the signal when its absolute value exceeds a certain threshold.
  • pitch shift – similar to pitch correction, this effect shifts a signal up or down in pitch. For example, a signal may be shifted an octave up or down. This is usually applied to the entire signal, and not to each note separately. One application of pitch shifting is pitch correction. Here a musical signal is tuned to the correct pitch using digital signal processing techniques. This effect is ubiquitous in karaoke machines and is often used to assist pop singers who sing out of tune. It is also used intentionally for aesthetic effect in such pop songs as Cher's "Believe" and Madonna's "Die Another Day".
  • time stretching – the opposite of pitch shift, that is, the process of changing the speed of an audio signal without affecting its pitch.
  • resonators – emphasize harmonic frequency content on specified frequencies.
  • robotic voice effects are used to make an actor's voice sound like a synthesized human voice.
  • synthesizer – generate artificially almost any sound by either imitating natural sounds or creating completely new sounds.
  • modulation – to change the frequency or amplitude of a carrier signal in relation to a predefined signal. Ring modulation, also known as amplitude modulation, is an effect made famous by Doctor Who's Daleks and commonly used throughout sci-fi.
  • compression – the reduction of the dynamic range of a sound to avoid unintentional fluctuation in the dynamics. Level compression is not to be confused with audio data compression, where the amount of data is reduced without affecting the amplitude of the sound it represents.
  • 3D audio effects – place sounds outside the stereo basis
  • sound on sound – to record over a recording without erasing. Originally accomplished by disabling the tape erase magnet. This allowed an artist to make parts of the work sound like a duet.
  • reverse echo – a swelling effect created by reversing an audio signal and recording echo and/or delay whilst the signal runs in reverse. When played back forward the last echos are heard before the effected sound creating a rush like swell preceding and during playback.[2]

See alsoEdit


  1. ^ The BBC Year Book 1931, p. 194ff.
  2. ^ Jimmy Page of Led Zeppelin used this effect in the bridge of Whole Lotta Love.

External linksEdit