How koalas sing low
Extra set of vocal cords lets males hit surprisingly low notes
By Beth Mole
Koalas have a newly discovered extra set of vocal cords that allows males to hit notes 20 times lower than expected.
Because the sizes of an animal’s voice box and its flapping vocal cords dictate the range of pitches an animal can make, a typical 8-kilogram koala should stick near the soprano section. But the male’s sexy mating songs, which to humans sound like a string of belches and snorts, dip to tones usually only made by elephant-sized mammals.