A TYRANNOSAURUS REX wouldn鈥檛 have heard your screams. Otto Gleich of the University of Regensburg, Germany, used data from birds to calculate the range of frequency of dinosaurs鈥� hearing.
The range of frequencies birds hear decreases with increasing body mass and increasing length of a key structure in the inner ear called the basilar papilla. Fossils don鈥檛 preserve this, so Gleich measured the cochlear duct, which is typically a third longer and is preserved in archaeopteryx, allosaurus and brachiosaurus.
He calculates that the hearing of archaeopteryx would have been within the range of modern birds, while a 1.4-tonne allosaurus would have heard best at 1.1 kilohertz, with a cut-off at 3 kHz 鈥� the pitch of a human scream. A 75-tonne brachiosaur would have heard best at 700 Hz, and been deaf above 2.4 kHz. The hearing of T. rex would likely have fallen between the two (Naturwissenschaften, vol 92, p 595).
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