Hearing beyond ears: Animals and their amazing listening techniques

Rabbits direct their ears toward sounds. Ear movement helps them to escape predators, but a rabbit’s ears also tell a lot about behavior. Erect ears mean they’re listening attentively. When one ear is up and one is down, the rabbit is listening passively. Ears resting against the back indicate a relaxed state of mind if ears are touching, but separated ears in the same position are a sign of fear.

Dogs can hear higher frequencies than humans. That’s why your dog reacts even when nothing seems to be there. Dogs can also differentiate their owner’s footsteps from those of strangers. Cat ears are even more sensitive! Dogs have 18 ear muscles, while cats have 30 and can even rotate them 180 degrees. So, don’t try to sneak up on your cat — it’s pointless.

Bats rely on echolocation to navigate during night flights. They send out ultrasonic sound waves from their mouths then the echo bounces back to the bat. Bats use this strategy to determine the size and location of objects and to find food in total darkness. Additionally, bats have 20 muscles to change the shape and direction of their ears to fine-tune their echo reception.

In the everlasting predator-prey race, the greater wax moths have managed to escape bat predation by evolving ultrasound sensitive ears. They have the highest frequency sensitivity recorded in the animal world and hear 150 times better than humans. They can even hear frequencies 100 hertz higher than bats.

When beetles, crickets, and moths hear ultrasonic waves of their predators they run away or fly in zigzagging or looping patterns. Some crickets and beetles produce clicking sounds to scare the predators away.

Underwater sonar is based on similar echolocation techniques bats and whales use to navigate at night or in the deep dark ocean. Like submarines, whales can navigate and find food using sound waves and sound reflections. Whistles and clicks produced by whales are thought to provide them with a 3D view of the world and are also important in communication between individuals.

Dolphins have ears; however, they navigate through the ocean by a mechanism similar to echolocation in bats. They produce sonic pulses from their foreheads that are reflected by the surroundings and then received by sound receptors in their jaws and teeth. Yes, that’s right! Hearing doesn’t necessarily have to be through ears, it can simply refer to information reception.

With their enormous ears, they can hear the sound of the clouds gathering prior to rain. Elephants can pick up infrasound waves — a low frequency humans can’t hear. They can also hear with their feet using nerve endings that detect ground vibrations. Some animals have receptors on parts of their bodies which convey vibrations and sound waves to the nervous system.

Not only do owls have excellent night vision and the ability to rotate their heads 360 degrees, but they also have remarkable hearing. Owls have asymmetrical ears, so when they fly, one ear picks up sounds from above while the other listens to sounds from below. This system working tandem with their night vision means their prey will most definitely get caught.

Some blind individuals have learned to use echolocation to "hear" their surroundings. One way they do this is by making clicking sounds with their mouths then listening to reverberations to estimate the size of a room or the distance to a wall or a fence. Some claim to be able to describe a place relying on echolocation alone!