In latest finding scientists discovered the Garkiners frogs, worlds smallest frogs, hears with its mouth. The amphibian from Seychelles islands are only 1 cm long and do not possess eardrums.
French scientists found with the help of x-rays the mouth of these frogs amplify frequencies spoken by species. Earlier the frogs were thought to be deaf and used cavity as a resonator.
According to Dr Renaud Boistel from CNRS and the University of Poitiers, such autitory system of the amphibian must be a way to survive on the ancient supercontinent Gondwana. His study is published in PNAS.
Daily Mail writes, The way sound is heard is common to many lineages of animals and appeared during the Triassic age, some 200-250 million years ago. Although the auditory systems of the four-legged animals have evolved, they have in common the middle ear with eardrum and ossicles, which emerged independently in the major lineages.
Well, for the frogs it is not like human beings. They dont have outer ear, but only a middle ear equipped with an eardrum, which is found on the surface of their head. The sound waves make these eardrums vibrate and the result of it is transmitted with the help of ossicles to the brain in the form of electric signals.
To test their hearing habit the research team set up loudspeakers to broadcast pre-recorded frog songs in their habitat. The male answered to the songs. With the help of X-ray imaging techniques the scientists found neither the muscles nor the pulmonary system of these frogs contributed to sound transmission to inner ears. It was confirmed the mouth acted as a resonator.