A patient with a facial nerve paralysis suffers from inability to dampen loud noises due to denervation of which muscle?
Stapedius is a small muscle in the ear innervated by the facial nerve. It dampens large vibrations of the stapes and the tympanic membrane; this allows the ear to diminish loud noises. If the facial nerve is paralyzed (as seen with Bell's palsy), the nerve to stapedius is lost, and the ear cannot lessen the vibrations of stapedius. This causes hyperacusis.
Posterior belly of digastric
Stapedius
Tensor tympani
Stylohyoid Muscle