Last week, I talked about how sound waves are very important to humans throughout our everyday lives, whether it be for communicating by speech, listening to music, or being aware of what is around us. Not only is sound important to humans, but animals also rely on the use of sound and the waves of sounds to survive in their environment. When you think about animals and their use of sound waves, I’m pretty sure you would be thinking of dolphins that use echolocation or may be bats that are practically blind, but I’m sure you have heard lots about those animals. I wanted to talk about a different animal that many may not know about and how they use sound waves to survive in the wild and communicate to one another.
Elephants are the largest land animal in the world, the largest elephant on record was an adult male African elephant weighing at about 24,000 pounds! As with their size, they have the largest brain of any land animal and behaviourally show a very high degree of intelligence. A large portion of their brain is focused on the ability to hear, many people assume that elephants have good hearing because of their very large ears, but those large flaps on their ears called pinnae are just useful for cooling themselves and showing different moods.
An elephant’s hearing receptors are placed under their trunks and feet. Many elephants that have been observed, placing their trunks against the ground showing that they are trying to detect sounds. They may also lift up one foot to place more pressure on the other three, so that it is firmly against the ground. Elephants do these things because elephants can send sound waves through the ground that other elephants are able to detect (elephants are able to send sounds through ground and air). These sounds are at very low frequencies called infrasound which is at 15Hz to 35Hz and these sounds can be as loud at 117dB. These sounds are able to travel very far, up to 10km!