【How-to】How does r2d2 speak - Howto.org

Burtt is notable for popularizing the Wilhelm Scream in-joke and creating many of the iconic sound effects heard in the Star Wars film franchise, including the ‘voice’ of R2-D2, the lightsaber hum, the sound of the blaster guns, the heavy-breathing sound of Darth Vader and creating the Ewoks’ language, ewokese.