believe it is kyma using a wacom tablet as a controller...
"I could reassemble the Wall-E vocals and perform it with a light
pen on a tablet. You could change pitch by moving the pen or the
pressure of the pen would sustain or stretch syllables or
consonants and you could get an additional level of performance
that way, kind of like playing a musical instrument. But that
process had artifacts in it, things that made it unlike human
speech, glitches you might say, things you might throw away if you
were trying to convince someone it was a human voice. That’s what
we liked, that electronic alias thing that went along with it,
because that helped make the illusion that the sound was coming
from a voice box or some kind of circuit depending on the character."
From this interview: http://www.moviesonline.ca/movienews_14930.html
Alex