Resonating device

Cicadas produce songs as part of their courtship display; the males of a number of species possess an abdomen that is largely hollow.

[9][10] In contrast, the basal hairy cicadas (Tettigarcta) do not emit an audible, airborne sound; like related leafhoppers, they instead transmit their vibrations through their substrate, turning the plants they perch upon into resonators.

[9][11] A species of aquatic bug, Micronecta scholtzi, has been recorded to produce sounds of 105 dB, the "highest ratio dB/body size".

[14] Other families of fish which have sound-generating mechanisms involving the swim bladder include:[14] Frogs possess vocal sacs which serve to enhance their nuptial calls.

[36] So specialized are these structures that scientists Herbert Lang and James Chapin remarked; "In no other mammal is everything so entirely subordinated to the organs of voice".

[37] Pinnipeds have been noted to employ this structure; the expanded nasal chambers of elephant and hooded seals act as resonant spaces that enhance their calls.

The expanded laryngeal lumen of California sea lions, the pharyngeal pouch of walrus, and the tracheal sacs of various phocids may also function in a similar manner.

[38] The ghara of the indian gharial is a specialized organ that acts as a resonating chamber; as a result, the call of a mature male can be heard up to 75 metres (82 yd) away.

[39][40] The crests of a number of lambeosaurine dinosaurs have been hypothesized to act as resonating chambers; reconstructed upper airways, specifically, the nasal passsages of Parasaurolophus, Lambeosaurus, Hypacrosaurus and Corythosaurus have been examined, and they were concluded to be able to enhance the vocalizations in life, and the different cranial crest shapes would have distinguished the sounds produced between genera.