The third of our soundtrack elements, in addition to narration and music, is the
category of "Sound Effects". Sound Effects (commonly abbreviated as
"FX") refer to the sounds—other than dialogue—that objects or people
make, along with those sounds that occur naturally in the background. All of these sounds are defined as "natural" necessarily only within the creative context of the movie and the filmmaker’s imagination. What they may or may not sound like in real life is not always in question. Who really knows what a three foot mosquito sounds like, so long as the sound effect works within the creative framework of the movie!
Sound effects can refer to events happening on or off screen. Footsteps of an actor may be an on screen event if we see the actor. Footsteps of the killer, coming down the hallway, outside of the closed door are an off screen event if all the audience sees is a shot of the closed door (from inside of the heroine’s room). Similarly, background ambience often refers to off screen activity that the audience may never see, such as a passing siren, birds & crickets, a thunderstorm, and so on.
Sound effects may be either frame-accurate or wild. If the effect is dependent on synchronizing exactly, frame-to-frame, with an on screen event -- it is known as a frame-accurate effect or more commonly, a "hard" effect. Examples include matching the sound of a gunshot with the firing of a gun, matching up door slams, whip cracks, sword clashes, punches, silverware being put on a plate, and so on.
If the sound of the effect only needs to be placed in the vicinity of an on screen event, but specific frame-to-frame synchronization is not important, then it is referred to as a wild or "soft" effect. Examples include environmental backgrounds (birds & crickets, rain, wind, ocean surf, traffic), engine noise, cafeteria ambience, crowd noises, applause, laughter, even music and narration.
The sound effects themselves can originate from a number of different sources. Many effects are lifted from special sound effects libraries that operate similarly to music libraries. Editors can pay per effect, or arrange blanket usage agreements. Most sound editors and studios maintain and compile their own elaborate libraries of sound effects, built up over the years from all of the films they have worked on as well as by swapping with fellow editors. Unlike music, it is very difficult to identify original ownership of
most sound effects—so, except in a few rare cases (recognizable synthesized effects), mere access to an effect is considered by most editors as an okay to use them. Legally speaking, that is false. However, the practice remains rampant in Hollywood.
Library effects include both "hard" effects as well as "wild" or
Sound effects don’t always come from a library. Quite often, they are recorded
right on the set during actual production. Effects may be recorded in "sync"
with picture during a take. This might include footsteps, door slams, explosions, car
crashes, virtually anything that takes place in front of the camera. Sometimes, though,
these sound effects coincide with live dialogue or other effects. In those instances, and
when time permits, the location sound mixer will try to record the sound effect
"clean" after the take has been shot. (Although it can be confusing, the term
"wild" also applies to anything recorded on the set without the camera rolling
in sync.) This newly recorded effect retains most, if not all, of the same ambience and
characteristics of the original take. It is also completely accurate in that the same
props were utilized.
Imagine yourself as an editor trying to match the sound of an arthritic woman slamming
the car door of a ‘62 Thunderbird coupe... from an effects library. There might be a
dozen or so car door slams, but probably none with the right speed, intensity,
delivery—not to mention car model. In some situations, exact matching of details may
be very critical, such as in a sales film or commercial, where it is illegal to substitute
the sound of another car for the one being featured.
Sound effects can be recorded after production, during editing. It is not uncommon for
a sound editor to send someone out (hopefully, a bona fide soundperson) in order to record
a list of needed effects. Freshly recorded sound effects are usually far superior to
anything in a library. By knowing as much as possible how the effect is to be utilized in
a given scene, the soundperson can do a better job of recording the sound effect to match.
The soundperson should avoid the temptation to record any more or less elements of the
effect than called for by the editor. For instance, if the editor needs the sound of a
hammer striking a nail, don’t embellish the track with background construction noises
and wild dialogue ("Hey, Ralph, hold this nail for me!").
Some effects don’t readily lend themselves to live recording. Ever try to get the
footsteps of a giant dinosaur? Editors and sound mixers will often conspire to create a
sound effect that doesn’t exist in real life (or does exist but doesn’t lend
itself to be easily recorded). Effects may be completely synthesized on electronic
instruments, or may be based on taking real sounds and electronically modifying them. Most
effects are composite effects, created like a musical chord, built up from a number of
simpler sounds (all of which may have also been modified).
Finally, many sound effects are ‘dubbed’ in, by means of a process known as
"Foley". Briefly, the Foley process consists of recording the sounds of an
artist while he mimics the actions of an actor on the screen. A short section of the film
is projected over and over again for the Foley artist (also known as the "Foley
walker"). The artist watches every movement of the actor very carefully, and mimics
both the action and rhythm. The artist performs those same actions using a variety of
props, and these actions are recorded in sync with the picture. For instance, the Foley
walker may imitate the actor taking out a gun from a holster, or sitting down in a squeaky
chair, or shuffling some papers in his hand.
In addition to mimicking simple actions, the Foley artist will also dub fight punches,
hugs, kisses, swordplay, head scratching, and anything else that emotes sound—no
matter how subtle.
Then there are the footsteps, which are what Foley people are best known for. Every
actor walks. Sometimes we see his feet moving, other times we only sense the movement
because the camera is in close. The Foley artist will recreate all of the footsteps of
each actor, regardless of whether or not the steps are seen or implied. To assist in
making the Foley footsteps match the environment on screen, the inside of the Foley
recording stage is equipped with a multitude of small troughs known as Foley pits. Each
Foley pit is a small rectangular area filled or covered with a different texture, such as
concrete, dirt, linoleum, carpet, hardwood flooring, marble, grass, brush & twigs,
sand, cobblestone, steel plate, and so on. In addition, there is a small wading pool of
water for creating aquatic sound effects. The Foley walker also has access to a wide array
of footwear, ranging from men’s combat boots to women’s high heels (irregardless
of whether the Foley artist is male or female!) in order to accurately recreate all of the
footsteps as well as mere body shuffles.