Darth Vader may have the most famous voice in the Star Wars movies—"Luuuuke, I am your faaaather"—but the most interesting character voice belongs to Chewbacca, Han Solo's furry friend.
The voice is the creation of Ben Burtt, the sound designer of the film series. Chewie's vocalizations were created from actual field recordings of bears, lions, badgers, and other animals.
When Star Wars producer Gary Kurtz came calling, Burtt was a sound-obsessed student at USC's film school. Burtt read the script, saw some of the preliminary art, and embarked on a year-long quest to record sounds in the field that he could cut together into the movie's audio design.
Chewbacca—and the imaginary species to which he belonged, the Wookiee—presented particular challenges. "He didn't have articulated lips," Burtt recalled. "He could basically open and close his mouth. So you also needed to create a sound which would be believable coming from a mouth that was operated like his."
Bears were an obvious candidate. They, too, vocalize from the backs of their throats, so it works with the limitations of the Chewbacca mouth. So, Burtt went around recording bears with a mono Nagra tape recorder. "I'd call somebody up and say, 'I hear you have a trained bear that makes a funny noise,'" he told one interviewer. A four-month-old Cinnamon bear provided much of the material, according to one account. But there are also mentions—throughout the many articles about Star Wars sound design—of three other bears, a badger, a lion, a seal, and a walrus from Long Beach.
"One time I went to Marineland down in Long Beach, CA, to record a walrus for a possible Wookiee effect," Burtt said in another interview. "Its pool had been drained for cleaning—the walrus was stranded at the bottom, moaning—and that was the sound!"
Once he had all the raw recordings, Burtt coded them for emotional value, you might say.
"Out of all these recordings you could extract little bits of sound, little grunts, moans, and ughs and arghs and purring sounds, whatever it might be. I collected and put all on one tape all these sounds that had emotional feelings associated with them," he said in a Star Wars production video. "You play this sound and it sounded affectionate. You play this other sound and it sounded angry. In that manner, I had these categories of little sounds that each had an emotional tone associated with it. I began cutting those together to get a sense of speech out of Chewy."
Humans being humans, once Chewbacca's voice had been manufactured by Burtt, people began to imitate it with their own vocal chords.
There is even a tiny industry of YouTube tutorial makers who will give you step-by-step instructions on how to vocalize like Chewie. They've collectively received millions of views.