Yes, I have heard mine chatter like they see a bird outside the window. When they are in a deep sleep, they jerk about a bit and their whiskers start to flutter. Not unlike humans, I guess.
One of my cats does it too. He started it long time ago with small whiney noices, but it has now reached to a full meowing. He doesn't quite sound like himself when he does it and the other cats are always wondering what is going on.
Sometimes I'm almost sure he is having a nightmare and go to pet and calm him, but what would he have nightmares of, he's never had anything bad happen to him.