A machine became a movie environment

Ben Burtt recalls recording carbon-arc lamps with a servicing company for The Empire Strikes Back. Mechanical sounds helped build the carbon-freezing chamber's atmosphere; slowed squeals contributed to Han's freezing scene.

An alien voice still needed a performance

In the Return of the Jedi interview, Burtt describes drawing on existing languages for Ewokese. One contributor, Kosi Unkov, spoke Kalmuck and told stories in the studio. Emotion and delivery were part of the raw material, alongside the words.