According to the National Institute for Occupational Safety and Health (NIOSH), 22 million Americans are exposed daily to hazardous noise on the job, putting them at risk of developing permanent, incurable hearing loss or tinnitus. An estimated $242 million is spent annually on worker's compensation for hearing loss disability.
Hearing loss happens for many reasons. Some people lose their hearing slowly as they age. This condition is known as presbycusis (prez-buh-KYOO-sis). Doctors do not know why presbycusis happens, but it seems to run in families.
After a decade of war, America is well schooled on post-traumatic stress, lost limbs and traumatic brain injury, but the most common injury sustained by U.S. troops is literally a silent wound: hearing loss, according to NBC News.