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 inner ear In the inner ear, the cochlea is the hearing part of the ear. The cochlea is a fluid-filled spiral tube. The vibrations caused by sound pass from the stapes through the oval window and into the cochlea. The cochlea is lined with thousands of tiny hair cells.