A study published in the American Journal of Adolescent Health shows that high-frequency hearing loss among some teenage girls has risen from around 10 percent to almost 20 percent in 24 years.

Researchers in the US have examined the ears of 8,710 teenage girls who lived in foster care facilities between 1985 and 2008. At the beginning of the study, 10.1 percent of the foster care girls were diagnosed with high-frequency hearing loss. Twenty-four years later, that figure has nearly doubled to 19.2 percent, the researchers found.
Among the girls who was diagnosed with a hearing loss, the proportion who had a mild hearing loss or a more severe hearing loss rose from 26 percent in 1985 to 61 percent in 2008.

Since 2001, the researchers have also been asking the teenagers about their use of personal listening devices (e.g. MP3-players). In 2001, 18 percent said they listened to music through headsets. In 2008 this figure has grown fourfold to 76 percent. Not just that, but the number of girls who listened for more than three hours per day tripled during that period, according to the study. 

Tinnitus has tripled 

The prevalence of tinnitus has tripled from 4.6 percent in 2001 to 12.5 percent in 2008. Of the teens with tinnitus, 99.7 percent used the listening devices.
Girls who listened to personal music devices were 80 percent more likely to have impaired hearing than those who didn't use the devices.

Even though the findings show an association between personal music players and hearing problems, it doesn't show cause-and-effect, according to the study author professor Abbey Berg, Department of Biology and Health Sciences at Pace University in New York.

Besides the noise exposure from the personal music players, other factors such as poverty, poor air quality, substance abuse and risk-taking behavior could add to the hearing losses, she said.

Sources: www.jahoonline.org, www.latimes.com and www.businessweek.com