Cochlea is the sense organ for hearing; consisting of three fluid-filled chambers.
It is the portion of the inner ear; coiled structure shaped and resembles the shell of a snail.
This spiral-shaped structure (organ of corti) in the inner ear contains mechanoreceptors known as hair cells for hearing.
Cochlea converts the sound to action potentials. When there are vibrations of fluid in the cochlea it causes the hairs of receptor hair cells to bend. Thus generating action potentials in nearby neurons.