Nearly one in five American teenagers has some degree of hearing loss. This is a sharp increase from just 15 years ago, a study shows. The main cause is thought to be teen’s use of ear buds.

One in five American teens, almost 6.5 million adolescents, suffer from hearing impairment. A survey has shown an increase of 30 percent from studies conducted 12 years earlier. The young males had a higher rate of hearing loss than the young females. The study also showed that teens whose families were below the poverty line were more likely to have impaired hearing.

"What surprises us a little bit is the difference between the previous time that this data was gathered and the most recent," says the study’s lead author Josef Shargorodsky of Brigham and Women's Hospital in Boston.

“There was a 30 percent increase in prevalence of any hearing loss in this age group and there was a much greater, about 50 percent, increase in the prevalence of mild or worse hearing loss" he says.

After comparing the two studies, the researchers found that the percentage of participants with a hearing loss of 25 decibels or more had increased from 3.5 percent to 5.3 percent. If you have a hearing loss of over 25 decibels, then you could benefit from a hearing aid.

 
An iPod generation 
 
Although the study did not examine the reasons for the teenagers’ hearing loss, the researchers support the fact that listening to iPods and other portable music players with ear buds can be extremely harmful to your hearing.

“Listening to high-decibel noise for extended periods damages the hair cells – sensory receptors – in the inner ear, and the kind of hearing loss that results from that is irreversible”, says Margaret Cheesman, a researcher and professor at the National Centre for Audiology at the University of Western Ontario.

“Once you have hearing loss, there’s a greater risk of hearing loss progressing as you get older,” says William Slattery, a clinical professor in the Department of Otolaryngology at the University of Southern California in Los Angeles.

Altogether, more than 4,600 teens aged 12-19 participated in two national studies. The first test from the period 1988 to 1994 found that nearly 15 percent of the U.S. teens were hearing impaired, while the rate of teen hearing loss rose to 19,5 percent in a second test in 2005-2006. This proves a rise of about 31 percent. The study was published in the Journal of the American Medical Association, August 2010.

 
Sources: www.bloomberg.com and www.afp.com