Creating Sound Effects

If you are reading this, then you are probably not a professional sound designer. As such, you probably don't own a $2,000 microphone with tube preamp and top-notch digital conversion. But chances are you do have a Sound Blaster card (from Creative Technology, Ltd.) or something similar, and the $3 plastic microphone that came with your computer. This may very well be all you need to capture the necessary sound effects for your games. So let's set up shop! In the following section, we'll give you some practical advice from the trenches on proper setup, recording dos and don'ts, ways to make your own sounds, and where to find prerecorded sounds.

Setting Up

Before capturing sounds, take at least a few minutes to be sure that everything is set up properly for the task at hand. Make sure the microphone is properly plugged into your sound card, and unmute the microphone in your sound manager/mixer. I recommend temporarily plugging in headphones where your speakers are, because you are likely to spawn a feedback loop if you record while the speakers play back. (You are probably familiar with the loud shriek of feedback usually experienced at the high school dance or church picnic when someone memorably points the microphone toward the speakers.) Or you might just unplug the speakers while you record and then plug them back in to hear. It's up to you, but remember it's your ears.

Use whatever sound-editing software you choose (see Appendix E), and start by just recording yourself speaking. Take note of how your microphone sounds, as this will be what determines how your sound effects will go into the computer. Does it pick up other sounds in the room? If so, try to isolate your recording area with blankets or any other reflection-absorbing (or echo-absorbing) material.

Also check proximity to the microphone talk into it and note how close you are and what the sound is like at that point. For example, test as you move back in very small increments, saying, "Check 1 inch, check 3 inches, check 6 inches.…" Most run-of-the-mill cheap computer microphones will not pick up much beyond 6 inches, depending on volume.

And that's the other big thing volume. Set the volume level carefully so that you get your sound as loud as possible without passing 0 dB (usually indicated by a red line or clip on your decibel meter).

The Golden Rule of Digital Sound

Digital sound is measured in negative numbers going up to 0 dB (decibels). If the sound passes 0, digital clipping occurs. Digital clipping is like trying to run through a metal barred gate at top speed and it sounds that bad, too. So the golden rule of digital recording is: Don't go over 0 dB! And don't be a cowboy thinking this is like Ghostbusters ("Don't cross the streams"). Even if the marshmallow monster is eating your sister, don't go over 0 dB. It might make a cool distortion sound on your computer, but it won't on most.

Recording

The second important rule of recording your own sounds (after the golden one discussed above) is to always do several takes. Trust me: You may have absolutely nailed that punch-in-the-mouth sound effect, but the truth is, you don't know how good it really is until you've heard it over the background music and other sounds in your game. This is why you should have several takes to choose from. The more sound design you do, the more you realize how important it is to have several options. There are many complex factors at play once you start combining sounds (not to mention sound and animation), so don't be surprised if what you originally thought was the best take ends up being your worst, and vice versa. If there is only one take to choose from, then you could be in trouble.

Many beginners make the mistake of recording each take as a separate file. While there is nothing wrong with this, the more productive way to go about it is to just hit Record and make your sound repeatedly in various fashions. This is where the editing software comes in really handy you can just trim your one big recording down to the parts you like and save/cut/paste the takes as files later.

When you're stockpiling takes, it's best to have a good variety. So if you usually swing from the right to make your swinging-punch sound, do two from the right, two from the left. Do two close to the microphone, and two a little farther away. Again, you never know which will sound best until later, so it's better to have some choices.

"That's not the right sound!"

I think we're all pretty well aware that the punching sounds we hear in TV shows do not even closely resemble what a punch sounds like in real life. However, the way the mind perceives action in the two-dimensional world dictates that we need something a little more dramatic than the real thing to get the point across. This is the art of sound design using your imagination to figure out how to give more emphasis or even depth to the sound (like in karate movies) so that the listener is right there with you. So don't be afraid to venture beyond the realm of what may seem logical and try a completely different sound to achieve what you're looking for.

Sound events in real life usually have a certain order, not just one simple sound. To make a punch sound more dramatic, we have first a swinging sound, and then an impact sound. And maybe, to put the frosting on the cake, we add the "Uggh!" sound of the punch victim. These must be timed correctly in order to sound realistic. They may even have to overlap some. This brings us to the concept of layered sounds. A basketball-game scene doesn't just have the sound of the ball bouncing. It may have squeaky sneakers, ball passes, bodies colliding, crowd talking and cheering, and the like. The sounds all happen at different times, volume levels, and positions relative to the listener. Although the layering of sounds is really an advanced sound-design concept and not for the faint-of-heart programmer who just needs a couple of sounds to add to the game, it still can be a very good thing to have in mind while you're designing.

Try to be consistent in matching the point of view with the acoustic space of your sounds. (It just doesn't work well to have a bar-scene punch followed by some guy yelling "Uggh!" in a hollow-sounding gymnasium.) Consider your scene carefully if you want effective sound in your game. Careful sound planning can pay off every bit as well as the hours spent perfecting subtleties in the GUI and game play.

Below are a few possibilities for home-grown sound design that you may find helpful. Some are realistic, some are melodramatic and cartoony. It is up to the sound designer's imagination to effectively use these ideas and come up with more.

Table 12.1. Sounds from Scratch

Desired Sound	Materials with Which to Fake It
Arrow, swinging fist, or swinging anything	Swing various-sized sticks, wires, and so on about 6 inches from the microphone
Bushes	Broom straw rustling.
Electric shock	Two blocks of wood covered in sandpaper; make one long stroke.
Boiling water	Use a straw to make bubbles in water.
Crashes	Make a "crash box" a wooden box (or cardboard for smaller crashes) filled with clangy metal things. Toss in some glass and even plastic containers for variety. Seal it up well, and beat it around to get the crash effect. If you were backstage in a live theater, you might see a 2-by-4-by-2-foot box attached to a crank that spins it.
Mud	Put some newspaper in a few inches of water and slosh around with your hands or feet.
Telephone voice	Use the equalizer in your sound-editing software to remove the bass. Some programs even have a preset for phone voice.
Fire	Open an umbrella really fast for a burst of flames. Crumple up thick cellophane near the microphone for the crackle.
Horses	Knock coconut shells together. Cover them with cloth for galloping on grass, and so on.
Gunshot	Slap a ruler against various surfaces, or fold a belt in half and snap it.
Thunder	The easiest, most common way of getting a large, boomy sound is to take a recorded sound (such as waving posterboard or really low piano notes) and just slow it down substantially with the sound editor, maybe adding some reverb to make it ring out.
Aircraft such as airplanes or spaceships	You can make a multitude of aircraft and space sounds using a garden-variety hair dryer. Just record the motor sound starting up and turning off, and then, with the sound-editing program, slow down the sound or speed it up or try it in reverse!

Fact: Almost every sound in Star Wars was made by recording common everyday items and then making common alterations and modifications to the sounds, such as slowing them down, reversing them, or adding reverb. Try these on your recorded sounds and see what you come up with. To some extent it is even OK to use someone else's prerecorded sounds to play with and edit yourself; just be sure that you are making significant changes to the sounds, because it's not cool to steal.

You can find a brief list of online sound resources in Appendix E,"Developer Resources."