interview to a game developer - Wikidolist

Dernière modification : 2008/03/04 21:46

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 $60,000--and so is Ciani's talent. A
Ciani soundtrack will cost as much as $25,000. 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 sophistieated 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