part of part of contributes to morphology of conduit for facial nerve vestibulocochlear nerve internal ear anatomical conduit internal acoustic meatus Alternate def: The internal acoustic meatus (or internal auditory meatus ) is an opening on the medial surface of the petrous temporal bone. It is through this passageway that the facial nerve (cranial nerve VII) and vestibulocochlear nerve (cranial nerve VIII) pass to reach their sites of innervation. The vestibulocochlear nerve divides at the internal acoustic meatus to continue as separate vestibular and cochlear components. [MURDOCH:908]