African elephants use infrasound for long-distance communication. These low-frequency calls are rumbles with energy below, or partly below, the lower limit of human hearing.
An elephant’s rumble can travel over considerable distances through air and ground, allowing separated members of a family group to exchange information. Calls may help coordinate movement, maintain contact, advertise reproductive condition, or support social relationships.
Elephants also communicate through audible calls, touch, posture, movement, and vibrations transmitted through the ground. Infrasound is therefore one channel in a larger communication system, not the animals’ only language.
A common mix-up is confusing infrasound with ultrasound. Infrasound is below human hearing, generally under 20 hertz; ultrasound is above it. Elephants are not using echolocation when they produce these rumbles: echolocation involves listening for returning echoes, whereas elephant rumbles primarily carry social information.