Let's go listen to a movie

Can you imagine 'Star Wars' without the buzz of lightsabers? Without laser blasts or zooming spaceships? Everything you see in a movie has a world of sound carefully composed, mixed, and produced to help you to lose yourself in the film.

Patrick Fitzgerald heads up Polarity Post Production in San Francisco. He's been working as a sound designer in TV and film for more than 20 years. His credits include last year's "Shrek 2" and the Disney Channel's current "Higglytown Heroes."

Sound "hits you on a conscious and unconscious level," Mr. Fitzgerald says. "Ninety-five percent of sounds are background noise - you filter them out. But if they weren't there, it would seem empty." Sound designers provide that background noise - as well as the 5 percent of the sound a director does want his or her audience to focus on.

Where do you begin? "I like to start by making it sound like a real world," Fitzgerald says. He builds up the sound, one recording track at a time. If a particular scene is at a park, for example, "there might be kids' voices, birds, traffic, the wind whooshing the trees, footsteps." Once those sounds are in place, he starts filling in the rest of the sounds - actors' footsteps on gravel paths, the sound of a baseball bat hitting a ball, even the rustling of an actor's clothing. All of it has to be added to make the movie sound real.

Fitzgerald has a CD library of more than 50,000 sound effects. He has many more on a computer database.

"Sometimes it's possible to just drop the sound in," says Michael Masar, Polarity's operations manager for post production. "Normally, it has to be altered. Echo is added to suit the 'action space,' or the length might need trimming to fit the visuals." In other words, if the "crack" of a bat occurs in a baseball stadium, the recording may have to be altered to sound as though it's happening in a big space. The sound of a skateboarder going by in a scene has to fit the time that the skateboarder is in the shot. Making movie sounds is complicated. "The sounds you are hearing could actually be 10 or 12 'samples' woven together," Mr. Masar says.

Machines called samplers and mixing desks are used to combine sounds to make a new one. A sampler lets you select a sound, or just part of a sound, and alter it digitally. A mixing desk can blend sounds or change their tone, pitch, speed - or all three.

Jim McKee is part owner and sound designer at Earwax Productions, also in San Francisco. He has extensive experience in film, TV, radio, and theater sound effects, including "Cast Away" (2000), "The Secret Garden" (1993), and "Bram Stoker's Dracula" (1992).

When Mr. McKee gets a sound-design project, he starts with emotion. His goal is to add texture and convey a mood. He wants to add a deeper, almost unconscious, level of experience to the project.

He plays a clip from a project he's working on, a video presentation for a university. It shows a man walking forward and speaking as if to an invisible crowd. The sounds are from the Earwax sound-effects library: an onion being peeled and cellophane tape being pulled apart. Using his computer, McKee plays around with the sounds. The cellophane tape crackles as lights sparkle like fireworks. "I added echo to make it seem more magical and give a sense of the space," he explains, saying that the effects add an emotional element - an excitement and energy.

The designed sounds are recorded onto different audio tracks. Background music is on one track, dialogue on another, and so on. Many tracks may be combined for one scene.

Why can't filmmakers record the sound as they shoot the film? The answer: background noise. There's too much of it, particularly when shooting on location and not in a soundproof studio. Cameras can be noisy. Airplanes fly over. People move around off-camera.

A boom microphone, on a long pole, is good at picking up an actor's voice while filming. But it might not be able to get close enough without appearing in the shot. Often, actors rerecord their lines while watching the film. They must make their words match exactly the movements of their lips onscreen.

The other sound effects are rarely recordings of the original sounds. That's because - believe it or not - real sounds rarely sound real on film. Perhaps it's because recording devices aren't perfect.

McKee recalls a time he had to produce the sound of waves crashing on a beach. The live recording just didn't sound right.

"Waves are really hard to record," McKee notes. "We have somehow built into us what a wave sounds like, how each one crashes a different way." After four hours of work, "we listened, and it wasn't even close!" It was humbling, he says. He ended up using a lot of different waves from many different locations. "You learn a lot about tides, winds, and the way the slopes of beaches affect how waves break."

Fitzgerald also collects everyday items, packaging material, old magnetic tape, even a Mr. Potato Head toy, to help him simulate sounds that come from real objects.

He holds up a black balloon. "I made a whole bag of popcorn from this," he says. He bends the top with his thumb and releases it with a tiny "pop." He downloaded that noise, then used a sampler to vary it and create multiple pops.

To create the sound of metal morphing, "Terminator II"-style, for a car commercial, Fitzgerald's assistant was up to his elbows squashing ketchup, mustard, Jell-O, and dog food. "It was really kind of gross and disgusting," he says. But it made the right sound.

In the final stages of creating a movie's sound, a designer may oversee an army of 100 people. Effects editors go through the film and place a sound for everything that makes a noise - a car door slamming, for instance - from a sound-effects library. "Foley artists" might walk on pans of gravel in sync with an actor strolling down a gravel path in the film. They rustle clothes or pull chairs while following the action.

What's it like for a sound designer to experience a movie? "I try to turn off my listening ears," at a film, Fitzgerald says.

But while watching a "Star Wars" movie from the new trilogy, Fitzgerald couldn't help noticing the rumble of the spaceships. Ben Burtt, sound designer for all the Star Wars films, had changed the sound! Spaceships made "whoosh" noises in Episodes IV, V, and VI. But these spaceships rumbled like internal-combustion engines.

"The new trilogy is set further back in time," Fitzgerald figures, so "this was an older type of sound. It's hard not to appreciate great work when you hear it."

According to George Lucas, 'Sound is 50 percent of the motion picture.' If that's the case, sound designer Ben Burtt deserves half the credit. Mr. Burtt did the sound for all six 'Star Wars' movies, including 'Revenge of the Sith,' which opens Thursday (as if you didn't know). Here's how Burtt created some of the sounds that have transported audiences to such a believable galaxy far, far away:

Chewbacca: Fragments of walrus calls and other animal sounds were blended to create the Wookiee language.

Darth Vader: Burtt recorded himself breathing with scuba equipment and layered the sound under actor James Earl Jones's imperious voice.

Ewok language: Burtt combined Nepali, Mongolian, and Tibetan syllables with made-up words and a little pidgin English.

Laser blasts: The 'zing!' of a hammer striking a taut guy wire on a radio tower. Burtt stumbled upon this sound when he accidentally hit some guy wires on a hike.

Lightsaber: The hum is made by old movie projectors mixed with the buzz created by passing a microphone across a TV set. This layered sound was played back over a speaker. A handheld microphone waved near the speaker created the pitch shift - the whipping sound of the saber.

Spaceships (first trilogy): The rumble of a malfunctioning air conditioner was slowed and deepened.

Tie fighter: The trumpet of an elephant, electronically manipulated.

R2-D2: Real whistles and voices were mixed with water-pipe noises and electronically generated sound.

Imperial Walker: The war machines' footsteps were a combination of a modified machinist's punch press and bicycle chains dropped on concrete.

Speeder bike: A P-5 Mustang airplane and a P-38 Lockheed Interceptor.

Luke's landspeeder: The sound of the Los Angeles Harbor Freeway recorded through a vacuum-cleaner hose.

• For more on 'Star Wars' sound effects, see: www.filmsound.org/starwars or www.skysound.com