A Look at Hearing in Bugs, Cats and Other Animals

A fact that indicates just how important the ability to hear is to all living things on earth is that while researchers have discovered many types of reptiles, amphibians, fishes, and mammals who were blind, they have been unable to find any naturally deaf species. But while hearing is essential, animals don’t need ears to hear; vertebrates have ears, but invertebrates frequently use other sorts of sense organs to hear.

In the case of insects, they have extremely sensitive tympanal organs which offer excellent hearing capabilities. Certain fly species can locate their prey exclusively via its song from a substantial distance. In some species, tiny hairs take the place of ears; in spiders and cockroaches these hairs are on the legs, while in caterpillars they are along the surface of its body. Elephants not only have large ears, they can also hear using their feet. They are particularly attuned to low-frequency sounds, and can detect the sound of thunderstorms or the deep-voiced call of other elephants many kilometers away.

Sound travels both faster and farther through water than it does through the air, and even though fish don’t have ears, they can effectively detect sounds using lateral lines that run horizontally on the sides of their bodies. A marine mammal, dolphins have no ears, but have eardrums on the outside of their bodies that give them the best sense of hearing among animals, over 14 times better than human hearing.

Many animals not only hear better than we do, they hear more sounds, easily detecting sounds in frequency ranges far below or above the frequencies that we humans can hear. Among domesticated animals, cats have the sharpest hearing, and can hear frequencies between 45 Hz and 64,000 Hz (humans can hear frequencies between 64 Hz and 23,000 Hz). Owls also have phenomenal hearing, both in terms of acuity and reaction time; they can detect the exact location of a scurrying mouse in less than 0.01 seconds.

Bats and dolphins actually extend their hearing abilities using echolocation, a form of sonar in which they emit tiny clicks or chirps and then “see” the objects they bounce off of when the sounds return to them. This echolocation is so precise that with a single chirp, a dolphin or bat can tell the exact location, direction, size, and even the physical nature of objects in its environment. Scientists have proven that by using echolocation dolphins can detect objects the size of a small coin from over 70 meters away. And if you want a real display of hearing, bats can not only hear insects flying 30 feet away from them, they can then pursue and catch them in mid-air, all in total darkness.

A quick look around the animal world is a great way to remind ourselves how vital hearing is.