Causes of hyperacusis

The most common cause of hyperacusis is acoustic trauma, either acute (a single exposure to a very intense level) or chronic (sustained exposure over time to high levels). However, there are many causes that can lead to hyperacusis which, as we see in the following table, are not directly related to the inner ear as one might initially think.

Origin	Examples
Otological	Bell’s palsy Ramsay Hunt syndrome Ménière’s disease Perilymphatic fistula Superior semicircular canal dehiscence Acoustic trauma Barotrauma Noise-induced hearing loss Stapedectomy Tympanoplasty
Neurological	Autism Carotid aneurysm Middle cerebral aneurysm Migraine stroke Traumatic brain injury Chiari malformation Reflex sympathetic dystrophy Multiple sclerosis Migraine Epilepsy Myasthenia gravis Elevated cerebrospinal fluid pressure Primary thalamic deficiency Attention deficit disorder Anxiety and depression disorder Post-traumatic stress disorder Spinal anesthesia complication
Endocrine	Addison’s disease, Panhypopituitarism Hyperthyroidism
Infectious	Neurosyphilis Lyme disease Typhoid fever
Medication-related	Withdrawal from benzodiazepines and antidepressants Acute phenytoin intoxication
Deficiency	Magnesium Pyridoxine
Genetic or congenital	Williams syndrome Idiopathic hypercalcemia (Fanconi and Williams-Beuren syndrome) Cri-du-chat syndrome Tay–Sachs disease Cogan’s syndrome GM1 gangliosidosis Spina bifida
Other	Temporomandibular disorder Fibromyalgia

Table extracted from A Review of Hyperacusis and Future Directions: Part II., Pienkowski M, Tyler R et. al.

In addition to the “official” list of causes of hyperacusis, I have also observed a significant number of cases where ear irrigation for cerumen removal has triggered hyperacusis and/or tinnitus.

References

Tyler R, Pienkowski M, et. al. A Review of Hyperacusis and Future Directions: Part II. Measurement, Mechanisms, and Treatment. American Journal of Audiology 2014:23:420-436.