Both R2D2 and Wall-E's voices were designed by Ben Burtt, not coincidentally. Wall-E takes the character of the voiceless, childlike robot and fills
it with so much humanity that you feel like your heart might just burst
The first 40 minutes or so of Wall-E are almost completely without dialogue. Instead, the story is told visually.
[Apple reference]: Wally makes the classic Mac bootup sound when he turns on, and his love interest EVE looks like she was designed by Jonathan Ive.
Immediately, we realize this isn't your typical kiddie cartoon. No pop
culture jokes? No instantly-recognizable celebrity voices? This looks more like a beautiful, haunting sci-fi movie than a children's movie, because that's exactly what it is.
Article Link (Gizmodo)