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 a curled tube and acts as the hearing part of the inner ear. It contains an outer and inner chamber, both of which are filled with liquid. Within the inner chamber is the organ of corti, which contains thousands of hair cells, of which each one has minute formations called stereocilia.