There are two ways in which a dogs hearing is superior to a humans; 1) they can hear a wider range of high pitch sounds and 2) they can hear further distances. The increased range of frequencies is due to differences in the length and shape of the cochlea; a coiled cavity in our inner ear lined with cells that translate high and low frequencies into nerve impulses.

Dogs can hear further distances because the shape of the outer ear. Ears act as a funnel to capture sound waves. A dogs ears are larger and can swivel in the direction of a sound thus maximizing the sound waves collected. As you could imagine dogs with pointed ears (versus the cute floppy ears) have better hearing.

And for the cat lover, fun fact: Cats can hear even better than dogs!

Dogs have a couple adaptations that help them hear well. One is that they have larger ears than we do. Our actual ear hole is fairly small. Dogs have larger ears which capture more sound, and a wider range of frequencies. Dogs can also move their ears, aiming them at the sound and allowing them to better pick up the exact noises. The shape and size of the dog's ear is the primary factor in their hearing.

Dogs’ ears are shaped in a way that makes softer sounds louder to them. They also have more muscles that control their ears which allow them to move their ears better to focus on a sound. Dogs can also hear sounds that people can’t hear at all which is why a dog whistle bothers dogs, but people can’t even hear it. The reason they can hear a larger range of sound is also due to the shape (and size) of their ears.