Noise induced hearing loss is a permanent hearing impairment resulting from prolonged exposure to high levels of noise. One in 10 Americans has a hearing loss that affects his or her ability to understand normal speech. Excessive noise exposure is the most common cause of hearing loss. The National Institute of Health reports that about 15 percent of Americans aged 20 to 69 have high frequency hearing loss related to occupational or leisure activities. Because of occupational risk of noise induced hearing loss, there are government standards regulating allowable noise exposure. People working before the mid1960s may have been exposed to higher levels of noise where there were no laws mandating use of devices to protect hearing. Recent studies show an alarming increase in hearing loss in youngsters. Evidence suggests that loud rock music along with increased use of portable radios with earphones may be responsible for this phenomenon.