Bats rely on their hearing more than any other mammal. After all, bats navigate the night sky by hearing the results of their echolocation, their natural sonar system. Turns out that's just the beginning of what makes bat-hearing amazing.
In order to better hear the returning ultrasonic pulses that they send out, bats can actually change the structure of their ears, going from one extreme configuration to another in just a tenth of a second. This incredible ability was discovered by researchers at Virginia Tech, who used cutting-edge technology and computer analysis to first capture the high-speed movements of the bats' ears and then understand just why the ears were changing shape.
Head researcher Rolf Müller explains:
"Certain bats can deform the shapes of their ears in a way that changes the animal's ultrasonic hearing pattern. Within just one tenth of a second, these bats are able to change their outer ear shapes from one extreme configuration to another. In about 100 milliseconds, this type of bat can alter his ear shape significantly in ways that would suit different acoustic sensing tasks. A human blink of an eye takes two to three times as long. As a result of these shape changes, the shape of the animals' spatial hearing sensitivity also undergoes a qualitative change.
The researchers' computer analysis suggests that the different ear configurations emphasize different "spotlights" for the creatures' ultrasonic hearing. This means that, depending on how the bat has its ears arranged, it will get different types of information back from the echolocation pulses it emits. By quickly switching ear shapes, a bat can get much more information about its surroundings than would otherwise be possible.