Why It's So Special:
Against stiff competition, Wall-E is Pixar's most unusual hero - not least because he's a robot who communicates with a severely limited vocabulary.
Striving for realism, director Andrew Stanton avoided conventional voice casting and went to Burtt, the sound effects genius who pioneered the beeps and whistles of R2-D2.
Like his earlier creation, Burtt's genius here is to give Wall-E a distinctive character and humanity...despite his robotic origins. Ironically, Burtt ended up used his own voice as Wall-E's foundation, but fiddled with it to the point where it sounds mechanical.
] wanted was the illusion that these robot characters, the speech and sounds they made were really coming from their functions as machines...
The problem does go back, for me, to the sort of primal R2-D2 idea, which is how do you have a character not speak words or, in the case of Wall-E, just a very few words, but you understand what is going on in their head and they also seem to have a depth of character."