Definition of cocaine. : a bitter crystalline alkaloid C17H21NO4 obtained from coca leaves that is used especially in the form of its hydrochloride medically as a topical anesthetic and illicitly for its euphoric effects and that may result in a compulsive psychological need.
The inner hair cells transform the sound vibrations in the fluids of the cochlea into electrical signals that are then relayed via the auditory nerve to the auditory brainstem and to the auditory cortex.
Plural cochleae (kÅk'lÄ-Ä', -lÄ-Ä«') or cochleas. A spiral-shaped cavity of the inner ear and the main organ of hearing. The cochlea contains the nerve endings that transmit sound vibrations from the middle ear to the auditory nerve.