A South American cricket with ears on its legs processes sound in much the same way as humans, scientists at the University of Bristol have learned.
The discovery could assist the development of super-sensitive miniature hearing aids, researchers said.
In humans and other mammals, hearing works in three stages. First, the eardrum vibrates in response to sound waves. Next, the airborne vibrations are amplified by delicate bones in the middle ear.
Finally, hair cells in the fluid-filled inner air convert the vibrations into electrical nerve messages that are sent to the brain.
Scientists found that the South American bush cricket has evolved a similar system, despite having tiny ears located on its two front legs.
Like mammals, the cricket uses an arrangement of mechanical levers to transfer sound vibrations from the eardrum to the inner ear, where they are turned into electrochemical signals.
The cricket had a previously unknown inner ear organ, similar to the cochlea of mammals but 60 times smaller, that allowed it to listen to a wide range of frequencies.