“Chewbacca” isn’t a job that opens up very often. Everyone’s favorite Wookiee was played by Peter Mayhew in the original “Star Wars” movies, and that was all anyone needed for the next few decades.

“I knew the sound was part of the foundation of what the movie was going to be,” George Lucas explains in this exclusive clip from Midge Costin’s “Making Waves: The Art of Cinematic Sound.” Ben Burtt, ...