external auditory meatus

The ear canal (external auditory meatus, external acoustic meatus), is a tube running from the outer ear to the middle ear. The ear canal extends from the pinna to the eardrum and is about 26 mm in length and 7 mm in diameter.
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adjective
referring to hearing
external auditory canal or external auditory meatus = tube in the skull leading from the outer ear to the eardrum
internal auditory meatus = channel which takes the auditory nerve through the temporal bone
auditory nerve = the vestibulocochlear nerve, the eighth cranial nerve which governs hearing and balance