by Stacy Hackner

“Sharks have eyes and mouths, and we hear all about their ability to smell blood. How do they hear?” Once again, a visitor had me stumped. Despite their having only tiny holes for external ears, sharks actually have very acute hearing, I later learned. Like in humans and other mammals, the shark’s inner ear has tiny hairs called stereocilia that vibrate, which is interpreted by the brain as sound. The stereocilia are arranged in three fluid-filled tubes, allowing the shark to hear in multiple directions. (These tubes are also responsible for the shark’s sense of balance.)

Sharks can hear low frequencies much better than humans, ranging from 10-800 Hertz (for reference, humans can hear between 25-16,000 Hertz), and can hear prey up to 800 feet away. In combination with their formidable sense of smell and speed, this makes them fearsome predators. (The big ones, at least.)

The angel shark, with ears visible just behind the eyes.
Courtesy Grant Museum.

Sources:

Shark Trust

Sharks Interactive