Audio: Found Sound

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April 1996, Mark Steensland

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Sound effects have immense value in video production. The ability to re-create an "aural environment" after the shooting is done gives videomakers much more control over their work, both enhancing the final product and helping to simplify the capturing of visual footage.

Sound effects have immense value in video production. The ability to re-create an "aural environment" after the shooting is done gives videomakers much more control over their work, both enhancing the final product and helping to simplify the capturing of visual footage.

For example, shooting a street scene during actual rush hour traffic would be pointless. The sound of real cars would drown out the dialog. But by shooting the scene during quiet hours and adding the sound effects later, you can create the illusion of rush hour and still be able to hear the dialog because both sets of sounds are separate and independently adjustable.

In feature film production, almost none of the original sound recorded during the location shoot ends up in the final version - not even dialog. Instead, technicians have painstakingly recreated nearly everything you hear using sound effects libraries or sound effects artists on a Foley stage (see sidebar). On a Hollywood mixing stage, there are anywhere between 60 and 120 audio playback machines, enabling the mixer to adjust every single sound effect independently and accurately.

The good news? You don't have to have Godzilla's mixing board to get great sound. With a little ingenuity and a little time, you can create stunning sound effects that will lift your video to a higher level.

But Where Do They Come From?
There are two ways to get sound effects: you either make them yourself, or rely on an outside source.

Outside sources are numerous. The most obvious are sound effects libraries. Just as there are buy-out music libraries, there are also buy-out effects libraries. These work by charging a big dollar amount - starting at around $75 in most cases - for a CD of effects you can use wherever or whenever you want.

Libraries aren't the only outside source. A number of electronic keyboards and computer systems contain banks of sound effects. Many synthesizers now come equipped with clapping sounds or animal sounds or wind or thunder.

Sampling keyboards - which record instruments digitally and then use that information to turn your keyboard into that instrument - aren't just for music. Record sound effects with your sampler and you can turn a German Shepherd into a Poodle, simply by adjusting the pitch of the dog's barking. Many sampling keyboards even come with sound effects already on disk.

Other sound effects devices exist, too. Videonics, for example, has a device they call the Boing Box. Like a keyboard dedicated to sound effects, this product contains 60 different sound effects from footsteps to animals. Like a keyboard, the Boing Box stores sounds in memory with numbered entries. Pick the effect, push play and listen.

All Time, No Money
So all you've got is you, your camcorder and the time it will take? That's okay, too. Just add creativity.

The first step is to make sure you have as much control as possible over your recording conditions. This not only means a reasonably soundproof room in which to work, but also few microphones and - in the best scenario - a tape recorder with adjustable speed and pitch.

If you have a mixing board, don't use it now. Remember that you should record all sounds in what's called their "dry" form. This means with no effects. Once you get into mixing, you can change the sound if you need to. But if you record thesound with effects already on it, you can't undo them. Any adjustment you can make while recording is one you can make later, so wait.

Gather everything you will need and can use during one session. A chalkboard or dry erase board can help you keep track of the recorded effects if you're recording the sounds with your video camera. You can't see sounds, so by writing the sound effect title and its marker (see sidebar) on a piece of paper and recording a few seconds of it before performing each sound effect, you have a quick and easy visual reference when editing.

If recording on an audio tape machine, don't forget to speak the title of each effect as clearly as possible into the microphone before recording.

Remember also that different microphones have different properties and therefore create different results. Think about those things that can heighten the effectiveness of your sound effect. Recording an effect with an omnidirectional mike in a room with some echo to it will be different from recording the same sound in an acoustically dampened ("dead") room with a shotgun mike trained an inch from the same sound source. Record an effect both ways and the difference may well surprise you.

Types of Effects
Effects can be divided into two categories: found and created. Found sounds are those which you can get easily enough by re-recording the item itself. Door slams, car engines starting and train whistles are good examples of found sounds.

Created sounds are those you'll need to create because recording the live item is too dangerous or simply impossible. Earthquakes and bomb blasts aren't effects readily recordable. Yes, you could probably find these effects in any sound library. But you can also create a good likeness of these sounds yourself.

Remember, our primary sensory input is visual. Without a visual reference, it's often difficult to tell the source of a single sound. That's why the key to this process is to learn to listen without seeing.

Get a piece of wax paper and a piece of cellophane. Each of these should be roughly square in size. Now take the piece of wax paper in your hands and gently crinkle it. With your eyes open, all you hear is wax paper crinkling. Why? Because you see it as well. Now close your eyes. What could it sound like now? How about fire? Try watching a close-up of fire with the sound off. Crinkle the wax paper and look at the screen. Because you see fire, your ears want to hear fire as well. This is the secret of sound effects.

The sound of footfalls in snow is as easy pressing your palm into a bowl filled with corn starch. And rain doesn't have to be wet - try sprinkling bird seed or sand on foil or wax paper stretched between two chairs. Punching the sofa out is plenty safer than having your actors really beat each other up. In the world of sound effects, corn flakes can become leaves and a stapler can become a cocking gun. The bottom line is that as long as the effect is combined with the right image, no one will know the difference.

Now let's look at two examples in detail. Remember our cellophane? It works well for fire, but in your video, the black-mustached villain in a stovepipe hat has just planted a stick of dynamite in the entrance to a mine. Take the cellophane, gather in the ends and twist it as tightly as you can into a thin strip. Now release one end. As it unwraps itself, you have the perfect sound equivalent of a fuse burning.

Now what about the scene where your heroes find themselves in the collapsing mineshaft? A large cardboard box lid and some rocks will do the trick. Put the rocks in the lid and hold it directly above your microphone. By tilting the box lid back and forth, you get the sound equivalent of a terrible rumbling. It may look silly, but remember - it only matters what it sounds like.

This effect can be heightened if you have speed control over your recording and/or playback medium. For example, by recording the rocks in the box and then slowing the sound down by fifty percent, the rocks sound huge. For most video machines, this simply isn't an option. Even if you have a deck with a jog/shuttle control, you won't be able to control the sound as well as you can with a tape recorder that has adjustable speed and pitch.

This is why it's a good idea to record your sounds "dry" - without any effects whatsoever. That way, you can wait until you run them through a mixing board or transfer them to videotape to add effects such as speed changes, reverb, etc. That way, if you end up with a sound effect you don't like, you can always go back to the dry sound and do it again.

Once you've recorded all your sounds, you're ready to move on to the next phase.

Mixing
If you recorded your sound effects on videotape, you're one step closer than if you recorded them on tape. You audiotape people need to get the effects onto videotape so that you can edit them. So why didn't you just record them on videotape in the first place? Because going from tape to video gives you one more step of control.

Videotape has (at most) only a few tracks of audio. If you have control over what gets recorded onto those tracks, and you won't have more than one sound effect in any scene, you're ready to move ahead.

But what if you have more than one sound effect in a scene? Perhaps you have a scene where a couple is driving in the rain at night. That means three effects. The most convenient - and perhaps most expensive - way to handle the situation is to use a multi-track audiotape machine. This will allow you to record each effect on a separate track, then mix the results together into a single track of audio.

But what if the recording method you're using will only support two tracks of audio? Unless you've recorded all of your sound effects together on a single track (which you shouldn't have done even if you could), you'll need to put them together somehow. This is where the technique of bouncing comes in handy.

Bouncing is a method to get more tracks out of a multi-track tape machine than you have. By recording sounds on three tracks of your four-track machine, you can then record those three down to one track and leave the other three open - giving you three more tracks than you really have.

You'll obviously lose some quality each time you re-record, but by knowing about this potential quality loss, you can make the appropriate adjustments to lessen the degradation. Even with a two-track audio tape recorder, you can still use the same technique to increase your number of tracks. The only limitation to the number of times you can implement this technique, of course, is sound quality.

But keep in mind that some sounds don't necessarily need to be crystal clear - a rain effect can stand transfer a number of times because of its placement in the far background of the final mix. This is why such effects, along with ambient room tone and other such continuous background noises, are called "beds" - they're at the bottom of your mix.

The other benefit of mixing is the ability to create new sounds by combining two or more effects. Again, the only limitation in creating sounds is your imagination. Try things that don't seem like they go together, such as a running faucet slowed down and the collapsing mineshaft you recorded earlier. The more you listen without seeing, the more sound effects you'll hear in all kinds of simple, everyday objects.

Armed with your effects tapes and your edit decision list, cut all your sound effects into the appropriate place. Now rewind your master and watch it from the beginning. The good news: now you know why big movies spend so much time on sound. Of the five senses, video can truly only tickle two - sight and sound. By paying as much attention to your soundtrack as you do to your camerawork, you can create truly ear-
opening videos.

But that's not the only good news. Carefully labeled, your original source tapes provide a terrific beginning to your own sound effects library. And because you have the sounds dry, you can alter the sound effects you already have to make new ones on future video projects.

One thing's for sure: you'll never be able to go back to plain vanilla sound again.


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