 The internal structures of the crest of Corythosaurus are quite complex , making possible a call that could be used for warning or attracting a mate . <unk> passageways of Corythosaurus , as well as Hypacrosaurus and Lambeosaurus are S @-@ shaped , with Parasaurolophus only possessing U @-@ shaped tubes . Any vocalization would travel through these elaborate chambers , and probably get amplified . Scientists speculate that Corythosaurus could make loud , low pitched cries " like a wind or brass instrument " , such as a trombone . The sounds could serve to alert other Corythosaurus to the presence of food or a potential threat from a predator . The nasal passages emit low @-@ frequency sounds when Corythosaurus exhaled . The individual crests would produce different sounds , so it is likely that each species of lambeosaurine would have had a unique sound . However , even though the range for different lambeosaurine nasal passages vary , they all probable made low @-@ pitched sounds . This might be because low sounds ( below 400 Hz ) travel a set distance in any environment , while higher ( above 400 Hz ) sounds have a larger spread in the distance travelled . 
