^ Tyler RS, Pienkowski M, Roncancio ER, Jun HJ, Brozoski T, Dauman N, Dauman N, Andersson G, Keiner AJ, Cacace AT, Martin N, Moore BC (2014). "A review of hyperacusis and future directions: part I. Definitions and manifestations" (PDF). American Journal of Audiology. 23 (4): 402–19. doi:10.1044/2014_AJA-14-0010. PMID 25104073. Archived (PDF) from the original on May 9, 2018. Retrieved September 23, 2017.
Noise exposure. Exposure to loud noises can damage the outer hair cells, which are part of the inner ear. These hair cells do not grow back once they are damaged. Even short exposure to very loud sounds, such as gunfire, can be damaging to the ears and cause permanent hearing loss. Long periods of exposure to moderately loud sounds, such as factory noise or music played through earphones, can result in just as much damage to the inner ear, with permanent hearing loss and tinnitus. Listening to moderately loud sounds for hours at a young age carries a high risk of developing hearing loss and tinnitus later in life.
Millions of Americans experience tinnitus, often to a debilitating degree, making it one of the most common health conditions in the country. The U.S. Centers for Disease Control estimates that nearly 15% of the general public — over 50 million Americans — experience some form of tinnitus. Roughly 20 million people struggle with burdensome chronic tinnitus, while 2 million have extreme and debilitating cases.1