Call Me Crazy but......(#001)

I was just watching the movie "Transformers" and noticed something. These impossibly-massive metaphysically-advanced alien robot technology/lifeforms actually move their metal mouths when they speak (except BumbleBee, he speaks through the radio). Call me crazy but....something this advanced would not need to bother moving it's mouth to speak. Sound would just come out somewhere, or maybe it would communicate telepathically. Do you know what I mean? The movie was very realistic up until that point.