Elephants are capable of producing very low notes, at what are called “infrasonic” frequencies — that means the sounds they produce can actually extend below 20 hertz, the lowest frequency detectable by the human ear. Researchers have known about elephants’ infrasonic abilities for some time — but how are these sounds actually generated? That’s been less clear.
According to biologist Christian Herbst, first author of an enlightening new study on elephant vocalization, the vast majority of mammalian vocalizations rely on the vibration of vocal folds housed within the larynx, an organ known colloquially as the “voice box”. These oscillating layers of tissue are capable of producing an extraordinary range of frequencies across species, ranging from 9 Hz in whales to over 110,000 Hz in bats.