noun
also auditory
: either of the 8th pair of cranial nerves being a sensory nerve composed of two parts: (1) a part arising in the spiral ganglion of the cochlea and serving to conduct sensory stimuli from the organ of hearing to the brain and (2) a part arising from the vestibular ganglion of the internal auditory meatus and serving to conduct stimuli having to do with the maintenance of bodily equilibrium, the two entering the brain together through the lateral wall of the medulla — called also respectively (1) cochlear nerve, (2) vestibular nerve ; see ear illustration