Interview to a game developer

Alejo Duque

Sound in Video Games How do they make it? How do we use it?

by Josh Martin (Appeared in the October/November 1983 issue of "Video Games Player")

What is a video game without sound? Your ears tell you if your guns have

fired, whether you hit your target and when the monsters are coming.

There are trumpets of victory and the agony of defeat, not to mention

other nifty squeaks, squeals, screams and, on occasion, voices. Sound is

the unsung hero of the video game.

Somewhere in the wilds of New Jersey is a group of engineers and

technicians, gathered like scientists, thinking up sounds you have never

heard, for games that no one has ever played. This is the design team of

Activision. Elaborate precautions are taken to ensure secrecy at this

lab. Even a simple phone call from the outside must get special

clearance from a separate office in New York. Company officials strictly

limit outside contact for the engineers and technicians: "They don't

disturb them for any reason,"said an amazed secretary. "They're serious,

too." In this quiet atmosphere, designers work on sound effects for

explosions, rockets and symphony orchestras. As long as there have been

video games, there have been sounds to listen to while playing. Of

course, back in the early days, those sounds were pretty much limited to

the beep of a moving cursor as it hit the edge of a playing field.

Now, after years spent developing graphics, the Activision game

designers and others are going to work on soundtracks, to make what you

hear as good as what you see. The results are audible in home and arcade

games: better music, realistic action sounds, and high-quality voice

synthesis. Case in point: Pong, admittedly a pioneer game, used an

effect that sounded more like a beeping radar screen than the bouncing

tennis ball it was supposed to represent. But the ball in Activision's

Tennis (Atari VCS) generates authentic "thwacks" when it's whacked with

a racket.

In the arcades, sound has also been evolving for the better. Who could

forget the gimmicky explosions in Space Invaders> They sounded more like

little electronic pops—hardly what you'd expect from an exploding space

ship. In Zaxxon, however, the devastation done to enemy fuel tanks and

rockets is often realistic enough to make you want to dive for cover.

(And let's not forget Sub-Roc, whose designers didn't forget impressive

sound effects when dreaming up those razzle-dazzle 3-D graphics.)

Activision's Dolphin demonstrates the most enterprising and innovative

exploitation of sound so far. Many games warn of impending danger with

an appropriately timed noise, but this one helps out with varying sonic

cues—differences in the sound's pitch signal the safest direction in

which to swim to avoid the killer octopus. Designing such effects is

obviously even more challenging—and sometimes as much fun—as playing

the game itself, according to some programmers.

Garry Kitchen is one of three brothers who design games for Activision.

Sound has become a new challenge for this video veteran. "I don't think

I've done as much with sound as I can," he says. "It's still mostly

support for graphics."

"You put sound in and take it out as you design your game," Kitchen

adds. "You have to consider that the sound must fit into the memory

that's available. It's a delicate balance between making things good and

making them fit."

For Mark Turmell, a game designer with Sirius (Beer Run, Sneakers,

Turmoil, Fast Eddie) soundtracks are the result of a lot of testing.

"It's an intricate process," he says. "Sounds are made up of numbers in

a computer. It often starts on a random basis."

Making that random sound perfect takes time, experience, and money.

Suzanne Ciani, the musician and electronic effects specialist whose work

can be heard in Bally's Xenon pinball game, works 12 to 18 hours a day,

with an array of 28 synthesizers. This custom-built equipment is

expensive—one synthesizer can cost ,000—and so is Ciani's talent. A

Ciani soundtrack will cost as much as ,000. Even the shortest

soundtrack can take weeks or even months to produce. In Turmell's

Turmoil, a Fox game introduced last November, there is a tune at the end

of play which is totally mathematically generated and synthesized.

According to Turmell, the music, which lasts 35 seconds, took over 70

hours of studio time to produce.

Sound is broken down into several categories. First there is real sound

which you can hear in your everyday experience, like a car horn or a dog

barking. Sometimes, soundtracks will use tapes with real sounds. But

more often, the sounds you hear while playing a video game are

mathematically generated and measured by frequency. Synthesized sound,

created by machines, registers as numbers on a dial in a game designer's

studio. Game designers consider three types of synthesized sound: high

frequency, low frequency, and white noise. White noise is created with a

random number generator, switching frequencies very fast. It is often

used for sounds like explosions or footsteps. Game designers who work on

soundtracks soon become versed in frequency numberd and the sounds they

represent. "I can pretty much tell what a series of numbers will sound

like," says Kitchen.

The sophisticated use of sound in Q*bert provides indication of where

soundtracks are going. Sound is used to give the characters personality.

It is also, in its own way, communicating to players. "Q*bert is not

trying to say anything understandable." says a Gottlieb programmer who

helped develop the game. "The sound is used to provide clues and enhance

effects. It gives you a clue about what's coming up in the game." There

are limits to sound. While home games can use better quality, arcade

games will continue to rely on graphics. As one sound programmer put it,

"In a war environment like the arcades, it's hard to hear anything." So

in an arcade game, explosions are just about the only sound that

matters, because they are about the only noises which can rise above the

din. Ed Rotberg, who worked on designing Asteroids and Battlezone, says

the arcade environment doesn't allow for sophisticatted sounds like

voice synthesis or player-produced music. "Arcade applications have to

wait until we have total environment games," he says. Such games would

be able to deal with four senses: sight, hearing, touch and smell. For

now, however, the main goal is realism: a car crash in which you feel

the twisted metal, a rocket that makes the hair on your neck stand up, a

bomb explosion that rocks you back from the controls. As the graphics

and sounds become more realistic, we care more about winning the game.

You have to rescue that human, not just some blip on a screen. There is

more riding on it. And if you think today's games sound tough, wait

until next year!

SIDEBAR: How do you make a sound?

There are hard sounds and soft sounds, representing different fre-

quencies and sound-wave patterns. Hard sound waves are jagged and look

like sawteeth. As a number pattern (which is how sound programmers

create it), a hard sound might read 1,2,3,1,2,3. This pattern can be

used to create a motorcycle noise. Another type of hard sound is created

by square-wave systems, which sets up number patterns like

1,1,3,3,1,1,3,3. The visual pattern is like a light being turned on and

off. A thunder clap can be made by using square-wave noise.

A soft sound creates a wiggly sound wave that can be seen in a number

pattern like 1,2,3,2,1,2,3,2. This is used to simulate footsteps or

gentle noises. In Q*bert, the sound programmer started at a computer

terminal by typing in numbers, which were turned into electrical power

in a Digital Analogue Converter (DAC). A DAC can produce up to 256

different voltage levels, so the programmer can type in numbers ranging

in size from 1 to 256.

Then the programmer determined the speed at which the numbers change,

which is the speed of running through different voltage levels. This

determines the resulting sound frequency. Howard Delman, a former

hardware designer with Atari who was responsible for Asteroids, explains

how an explosion is created:

"An explosion is a random selection of sound frequencies. It starts off

very loud and then falls off. The way to make one explosion different

from another is to select different frequencies. The sounds are all made

by selecting a group of frequencies using a Random Noise Generator.

"The Random Noise Generator circuit creates a wide spectrum of

frequencies simultaneously, creating a hissing sound—'white' noise.

Another circuit selectively eliminates certain frequencies; it is a

controllable filter. And a third circuit controls the volume of the

signal. When an explosion is started, this third circuit allows the

frequency to pass through at full volume, and then very quickly decays

the amplitude. We can restart the sound, however, to make a comp]ex

explosion."

An explosion for one of the big rocks in Asteroids uses lower

frequencies, hence the rumbling noise. A spaceship uses higher

frequencies.

The only software programming involves four choices of explosion

frequency circuits, to cover the different size rocks and the

spaceships. By comparison, each sound you hear in Q*bert is a different

software program, and there are about 25 small programs in the game.

Scanned and edited by Dennis Brown, dgbrown (at) pixesthesia (dot) com