What noise does a dinosaur make?

Except for today's bird, which are in the family of Theropod dinosaurs, no human or humanoid has ever heard a dinosaur. The dinosaurs, except for birds, were extinct far, far before the very first humans appeared on Earth.

I suppose you could say that the theropod dinosaurs tweeted and chirped, but it is hard to imagine that the giant Tyrannosaurus rex (Also a Theropod) tweeted!