Two elephant herds, kilometres apart and out of sight of one another, can hold a conversation we'd never even know was happening. Elephants speak in sounds too deep for human ears, and they listen not only with their ears but with their feet. In this entry of our Through Animal Eyes series, we explore the low, rumbling world that elephants inhabit.
It's a sense that turns the ground itself into a telephone line. See also the scent-world of how dogs smell the world and the electric sense in how sharks sense electricity.
The rumble below hearing
Much of an elephant's communication happens in infrasound ā sound at frequencies below about 20 hertz, the lower limit of human hearing. We can sometimes feel these rumbles as a faint vibration in the air, but we can't hear them at all.
Low-frequency sound has a special property: it travels much farther than high-pitched sound before fading away. That's exactly why elephants invest in it.
Producing these deep calls with a powerful voice box, an elephant can broadcast a message across a vast stretch of landscape.
Many of these calls have a faint, audible component too, which is why standing near an elephant you may feel a deep rumble in your chest as much as hear it.
Talking across the savanna
Through the air, an elephant's infrasonic calls can carry for several kilometres, and under the right conditions even farther. With them, scattered family members coordinate their movements, females advertise when they're ready to mate, and the herd warns of danger.
Each call also carries identity: elephants recognise specific individuals by voice, so a rumble isn't just a message but a name attached to it.
An entire social network spreads invisibly across the savanna, conducted in a register we can't perceive.
Calls also travel farther in the cool, still air of early morning and evening, and elephants seem to time their most important rumbles to these windows.
Listening through the ground
The most remarkable part is that elephants don't only send these signals through the air ā they send them through the earth. A powerful rumble creates seismic vibrations that ripple through the ground for kilometres.
Elephants appear to detect these tremors through sensitive cells in their feet and trunk, and by conducting vibrations up through their bones to the inner ear. They've been seen freezing and leaning forward, pressing their feet down, as if listening to the ground.
This seismic sense may let them detect distant herds, far-off thunderstorms, and other events long before any sound reaches them through the air.
There were even reports that some elephants moved to higher ground before the 2004 Indian Ocean tsunami, possibly sensing its seismic warning through the earth.
More than ears
Infrasound is just one channel in an elephant's rich sensory life. They also have what may be the most powerful sense of smell of any land animal, sweeping their trunks to read scents on the wind from miles away.
Their famous ears, beyond their role in hearing, work as enormous radiators that flush heat from the body in the African sun.
Vision is the least of their senses, so an elephant leans far more on sound, scent, and vibration to understand its world.
An elephant's trunk is the hub of this sensory world, doubling as nose, hand, snorkel, and sensitive vibration detector all at once.
Why elephants go low
There's a logic to all of this rooted in physics: big bodies and big vocal organs naturally produce deep, low-frequency sounds, and those are precisely the sounds that travel farthest. Evolution simply leaned into what a giant body does best.
The result is a communication system perfectly suited to animals that roam huge ranges and need to stay in touch across great distances.
For an elephant, "out of sight" is nowhere near "out of touch."
The same principle is why distant thunder reaches us as a deep rumble while the sharp crack stays local ā low frequencies simply go the distance.
What it's like to be an elephant
To sense the world as an elephant does is to feel conversations rolling through the ground beneath your feet and to hear voices from far beyond the horizon. It's a slow, deep, far-reaching way of perceiving the world ā fittingly grand for the largest animal that walks the land.
Frequently asked questions
Can elephants hear sounds we can't? Yes ā they communicate largely in infrasound, below the range of human hearing, which travels for kilometres.
Do elephants really hear with their feet? In a sense ā they detect ground-borne seismic vibrations through their feet and trunk, conducted to the inner ear.
How far can elephant calls travel? Several kilometres through the air, and seismic rumbles may travel even farther through the ground.
That's three more hidden senses. Revisit how cats see the world and how birds see ultraviolet ā and watch for more in the Through Animal Eyes series.