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.
The cochlea of mammals contains two types of sensory hair cells. One type, the outer hair cells, have almost no nerve connections to the brain and are mainly involved in amplifying incoming sounds and driving the movements of th ebasilar membrane that underlies al lthe cells of the organ of Corti.