X-ray imaging of tiny frogs’ bodies show that their big mouths resonate best around the frequency of the male’s calls - meaning they hear through their mouths.
One of the smallest known vertebrates, Gardiner’s frogs were long thought to be deaf, since they miss a middle ear to transmit sounds to the amphibian equivalent of the cochlea.
Reduced tissue thickness and fewer tissue layers between the mouth and the inner ear additionally help the frogs to perceive sound through their mouths.
The 11mm-long animals are found on only two islands in the Seychelles.
Read more at New Scientist