ATV refers to All Terrain Vehicle. It is also known as three wheeler, four wheeler, quadricycle, quad and quadbike. They are used by single operators. It is designed in such a way that it can handle wider variety of terrain.
The cochlea is the sense organ that translates sound into nerve impulses to be sent to the brain. Each person has two cochlea, one for each ear. The cochlea is a fluid-filled, snail shaped cavern in the mastoid bone of your skull behind each ear. Tiny bones in the middle ear transmit sound from the eardrum across the middle ear and vibrate against the cochlea.
The Cochlea is Similar to a Microphone. During the process of hearing, sound waves vibrate against the ear drum. Vibrations in ear require far less energy than vibrating fluid. Since the cochlea is fluid filled, there is a need to increase the amount of energy in order to adequately vibrate the fluid. In order to achieve this, the ear drum is about 13 times the size of the oval window.