What causes Hyperacusis?
Unfortunately, because Hyperacusis is so rare, little research has been done so little is known about it. The onset is usually caused by exposure to loud noise (either prolonged or a single episode) or a head injury. Some experts speculate that the cause is damage to the auditory nerves. Currently, a popular theory is that there has been a breakdown or dysfunction in the efferent portion of the auditory nerve. Efferent meaning fibers that originate in the brain which serve to regulate or inhibit incoming sounds.
