Elephants make lots of noises. With their long trunks, they can make loud trumpet sounds. They can also roar, grumble, and snort. If you have been to the zoo, you have probably heard some of these noises. But, most of the time, elephants talk to each other with very low, or infrasonic, sounds. These noises are so low that people can’t hear them. When it seems like elephants are being quiet, they might actually be having secret conversations.
Elephants can hear much lower noises than people can, but don’t always hear things the same way we do. Really low sounds can move through the ground, almost like a very small earthquake. These sounds are called rumbles. Elephants have specially padded feet that help them feel these rumbles. Once their big, squishy feet pick up a noise, the sound travels all the way up to their ears through their bones. So, elephants don’t just hear these super low sounds, they feel them, too! Elephants use these low noises to talk to each other over long distances. Different elephant families can hear each other from miles away.
Even though you can’t always hear them, people make rumbles, too. When we build houses, or even drive a car, we are sending messages to animals all around us. To elephants, these sounds are cues: clues from the environment that something is about to happen.
When people build big cities and busy roads, some elephants get scared. They know that roads can be dangerous, and people are not always safe to be around. As soon as they hear rumbles made by people, they run away. But, when other elephants make these sounds, they are not so scared. Elephants in Africa are very good at listening to rumbles. For them, rumbles are more than just noise – they can tell each rumble apart! From one sound, elephants know whether other elephants, people, or even thunderstorms are nearby.
Sometimes, elephants stand very still and swing their heads left and right. This helps them decide what to do. When they hear rumbles made by people, they stop and listen. This helps keep them safe from danger. If elephants hear something scary, they can run away.
Elephants are also good at figuring out how dangerous acoustic sounds, or the sounds that people can hear, might be. When played recordings of noise from bees and people, elephants ran farther away after hearing the bees, because bees often sting them. Elephants can also tell the difference between groups of people, and run farther from the ones who usually hunt them.
Elephants are great listeners. For a long time, however, people did not know if elephants could tell which rumbles came from elephants and which rumbles did not. Now, we know that they can! We also know that, sometimes, these rumbles can scare them. So, the next time you are in a car on a busy street or see someone building a brand new house, think of the elephants and remember: people make rumbles, too.
1. Mortimer B, Walker JA, Lolchuragi DS, Reinwald M, Daballen D. Noise matters: elephants show risk-avoidance behaviour in response to human-generated seismic cues. Proc R Soc B Biol Sci. 2021 Jun 30;288(1953):20210774.