Language of the elephant: elephants buzz with the vocal cords

Elephants communicate not only about loud horns. With the help of deep humming sounds they pick up over long distances in contact with other herds. How do they produce the infrasonic sounds, was unclear. Now researchers believe they have solved the mystery.


Want to tell wild elephants over long distances, they use infrasound. Rumbling is this kind of communication: The hum is so low that people they have little or no hearing. Until now it was unclear how to make the elephant. Some animals such as cats growl using muscle contractions, other mammals - including humans - compress a stream of air through her vocal cords. Now scientists have figured out by its own account, that elephants also use this mechanism.

The vocal cords of mammals are sitting in the larynx and vocal consist of muscle and vocal cords. About their position and power generating animal and different sound waves. The scientists led by Christian Herbst of the University of Vienna examined the larynx of an elephant, which was last fall at the Berlin Zoo died of natural causes: "We have put the larynx of the dead animal on a tube and warmed and humidified air is blown through the vocal cords" explains the fall.
The scientists from Austria, Germany and the United States recorded the movements of the vocal folds and the resulting noise generated. They were able to produce the low-frequency rumble alone with the larynx. This shows that the animals communicate using the vocal folds, the researchers write in the journal "Science" . Muscle contractions, as it uses about a cat would, however, is not produced with air.

"We have known for 150 years that the human voice is produced in the larynx," says Herbst. "But animals can be difficult to examine endoscopically there." Therefore, the question of how elephants produce infrasound, has long been unanswered.

Mammals of different species can produce with their vocal folds, a wide range of frequencies. The infrasonic elephant is about the great below 20 hertz, 10 hertz itself still may be able to perceive. The ultrasonic sounds, use the bats for orientation are, however, at frequencies from 9 to 200 kilohertz largely in the ultrasonic range. People can hear sound waves between 20 hertz and 20 kilohertz.