Do-you-think-he-saurus... Or Heard Us Even?
Using data from birds, which are close relatives of the dinosaurs, researcher Otto Gleich, from the University of Regensburg, has calculated the range of frequencies a dinosaur would have been able to hear. Amongst birds, hearing range drops with increasing body size and the length of an ear-structure called the basilar papilla. This isn't preserved in fossils, but it is typically two-thirds the size of the well-preserved cochlear duct. By measuring the sizes of the cochlear duct in an archaeopteryx, an allosaurus and a brachiosaur, the researchers estimate that archaeopteryx would have had a hearing range roughly equivalent to modern birds, a 1.5 tonne allosaurus would have heard best at 1.5 kHz and notes no higher than 3KHz, whilst a much larger 75 tonne brachiosaur would have heard best at 700 Hz and been deaf to sounds above 2.4 kHz. A T. rex would have had a hearing range somewhere between the allosaurus and the brachiosaur, and as a human scream has a pitch of over 3 kHz, it's likely that a Tyrannosaur could well have enjoyed you for lunch without having to endure the sound of your protestations. He would, however, have been well able to hear the sound of his stomach rumbling - at about 20 Hz - beforehand!