The most common cause of hyperacusis is overexposure to excessively high decibel levels. Some come down with hyperacusis suddenly by firing a gun, having an airbag deploy in their car, experiencing any extremely loud sound, taking ear sensitizing drugs, Lyme disease, Ménière's disease, head injury, or surgery. Others are born with sound sensitivity, develop Superior Canal Dehiscence Syndrome, have had a history of ear infections, or come from a family that has had hearing problems. The Diagnostic and Statistical Manual of Mental Disorders that is published by the American Psychiatric Association lists hyperacusis as one of the possible signs indicating phencyclidine intoxication. In TCM, deficiency of kidney energy and depressed liver Qi is the main cause of hyperacousia.

Other common causes include:
1. Air bag deployment
2. Bell's Palsy
3. Temporomandibular Joint Syndrome
4. Head injury
5. Unfortunate side effects of drugs
6. Lyme disease
7. Chronic ear infections
8. Auto immune disorders
9. Adverse reaction to medication or surgeries, particularly Central Nervous System drugs