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 vestibulocochlear and facial nerves both travel through a canal in the temporal bone, called the internal auditory meatus. The first part of the vestibulocochlear nerve, the vestibular nerve, detects balance from head and body motion. The second part of the vestibulocochlear, the cochlear nerve, receives auditory stimuli. The hair cells, or sensory cells, are responsible for transmitting the information from the inner ear to the brain.