Internal auricular branch

The internal auricular branch originates at the stylomastoid foramen, near the caudal auricular nerve and the digastric branch. It receives fibers from the auricular branch of the vagus nerve before leaving the facial canal by joining the facial nerve. It then runs dorsally between the external acoustic meatus and the mastoid process, before piercing the auricle at its base to supply the skin of the internal face. 

It is on the one hand motor of the small muscles of the auricle, and on the other hand sensitive by the fibers of the vagus nerve which are distributed to the skin of the external acoustic meatus and to the base of the concave face of the auricle.