From the Archive: Creating SFX

Editor’s note: “From AIR’s Archive” brings forward some of the lost (or long-buried) profiles and advice about audiocraft that we’ve collected over the years. This advice about creating audio special effects was first offered in 2006. 

by Jerry Stearns

Sound conveys meaning. Sound stimulates visual images in our minds. Radio theater/ audio theater is telling a story by the careful mixing of sounds – both verbal and non-verbal. Radio is a hot medium, that is, the listener’s imagination and experience are involved in giving the story depth, substance and meaning.

Sound effects can be used for such things as setting and place, conveying action, solving certain narrative problems, and evoking characterizations.

In radio theater we have four objects to work with:

◦    Dialogue

◦    Sound Effects

◦    Music

◦    Silence

Using Sound Effects

Real sounds are more convincing than synthesized ones. But most things do not make the sound we think they make.

A sound effect is like a mini-drama, with a beginning, middle, and end. It is meant to indicate some action or event, and it should follow through to complete that action.

A sound effect most often consists of more than one part – usually several parts. A door opening isn’t just one click of the latch. Answering the telephone must be more than the simple and quiet click we actually make picking up the receiver. Rattle, rattle!

Most effects you hear – especially in the movies – are actually the result of at least two people, somewhere else, doing something with two or more objects, probably unrelated to what you are supposed to be hearing.

In general, the listener should hear the sound effect before the dialogue or action refers to it, if it is referred to at all.

Acoustic Space

“Every place on the planet has it’s own voice. And that voice changes with the time of day and time of the year.”

Pre-recorded sound effects are recorded in a particular place and sound environment. This probably is NOT the same “acoustic space” that your actor’s are, or where you want them to sound like they are.

An effect that doesn’t sound like it’s in the same place as the actors can alter or destroy the image you were trying to build for the listener. Don’t have a character go outside, but sound like she is walking down a long hallway. If possible, record your own effects in the same place that the actors are recorded.

Kinds and Categories of Sound Effects

Literal effects are intended to sound like what they are supposed to be. A kind of literal effect is the “emblematic” or “associative” sound effect. It associates in our minds with specific events, and tells us clearly what is happening. Once established, they can be used again to return to a place, event, or image, easily and quickly.

What are the elements of a sound that create that desired image, or make that particular association? (Running water: add to it the sound of moving a shower curtain, and it is distinguished from brushing teeth or washing dishes.)

Non-literal effects are sounds used to indicate an event, without being “like” the actual sound of it – especially for things that don’t have a characteristic sound or events that don’t actually happen. What do ghosts sound like? Or sharks passing under water? Often music is used to indicate these sounds.

Ambiences (atmospheres, or backgrounds) are sounds that identify location, setting, or historical time. A good unedited background can cover a choppily edited dialogue, making it sound real and continuous.

Discrete (spot) effects indicate individual events; what, how, and how much.

1. Brief individual effects, or composites of effects, specifically placed and timed for a single action.

2. Foley effects are incidental naturalistic sounds of movement and business, recorded to match the action. Footsteps, opening doors, pouring drinks, etc. Foley effects are spot effects, but spot effects are not always foley effects. (Named after Jack Foley, a second unit director for Universal Studios in the 1940s.)

3. Some foley effects can be recorded live, on the voice track. Having the actors make the sound can aid in timing the effect, and it helps the actor’s voice convey the movement, but it can also complicate the recording session.

Walla (crowds): The “walla walla” sound of many people in a crowded situation, without specific voices or words being distinguishable.

1. Bar wallas differ from ball game wallas, and differ from concert audience wallas, etc.

2. Bars, for example, are a difficult environment to control – like what music is being played, or how loudly, or when distractions occur. You may have to record a lot of this background to be able to find enough for you to use.

3. Often a foreign crowd scene works well because you’ll never have English words popping up when you don’t expect or want them to.

Silence. A dramatic element. It can be very loud.


Mixing two or more sounds together to create a combined sound that is more than each of the individual sounds alone. Often consists of non-specific background with added “associative” sounds to help identify or differentiate specifics.

A restaurant scene might begin with voices and kitchen noises in background. Add foreground plates, silverware, and music and we begin to see what kind of restaurant we are in.

A wilderness scene might use birds and insects, but add distant wolf howls, or close-up footsteps and chain saws, and the story already begins to unfold without any dialogue.

Think about these suggestions the next time you start to create effects.

• Jerry Stearns is the executive producer of Great Northern Radio Theater in Minneapolis, Minnesota – you can learn more by writing to him at jstearns at Stearns is affiliated with The National Audio Theatre Festivals.

For more on audio effects, check out the “Everything Sounds” episode “Foley Follies” and accompanying blog post about foley tips and tricks; the College Humor mockumentary “Labor of Love,” about a foley artist for adult films (featured in the Public Media Scan); and this fun FilmSound post about weird and unlikely sources of special effect sounds. Be sure to check out RTDNA’s guidelines for ethical video and audio editing, too, which includes advice for using effects.