How do other animals hear?

A MAP OF SOUND

The ability of bats to map their surroundings through sound is one of the most studied animal senses. Contrary to popular belief, these flying mammals are not blind, but their eyes are of little use to them when they catch insects in flight at night. The shrieks of bats, inaudible to the human ear, bounce off their surroundings and their moving prey. The timing of the return signal, its direction and change of frequency—due to the Doppler effect, like when an ambulance with a wailing siren passes by—allow them to hunt with incredible accuracy. This is known as Echolocation.

X-RAY VISION

The sonar system of dolphins and toothed whales is actually the same echolocation system used by bats, only underwater. The sounds produced by these marine mammals allow them to form a mental map of their surroundings in three dimensions. But this ability is even more incredible—the sound waves emitted by dolphins can penetrate through certain objects and soft tissues, providing the animal with a kind of X-ray vision of their possible prey or threats. Nowadays, engineers are trying to copy this ability to improve sonar detectors.

This diagram illustrates that most animals can hear sounds at much higher frequencies than humans.  Which is why sirens set  dogs off barking as it hurts their ears!