A recent study has found that the endangered and earless Gardiner's frogs can actually hear with their mouths.

Tinier than your finger nail and one of the smallest in the world, Gardiner's frogs are only found in the Republic of Seychelles, a nation of islands in the Indian Ocean. They’re now endangered as people, other species, and fires invade their island habitat. In a recent study, another unique trait was found: this earless frog can hear with its mouth.

Unlike most other four-legged animals, Gardiner’s frogs are missing the middle ear region that transports sound wave vibrations from the environment to the brain.

Researchers wanted to solve the mystery of why this supposedly deaf frog would make its high-pitched, loud calling sound.

After playing their call recordings in their forest habitat, researchers saw the frogs actually respond to the sounds. According to one researcher, Dr. Justin Gerlach, “Either they…move to face where the call is coming from or quite often they will call in response.”

Not only did the mouth cavity magnify sound like a guitar, but the frog’s thinner tissue between its inner ear and mouth allowed it to identify sound effectively.

Dr. Renaud Boistel, who led the study, hopes that one day these findings may help people who are deaf.