The proportion of teens in the United States with slighthearing loss has increased 30% in the last 15 years, and the number with mild or worse hearing loss has increased 77%, researchers said Tuesday.
One in every five teens now has at least a slight hearing loss, which can affect learning, speech perception, social skills development and self-image; one in every 20 has a more severe loss.
The authors of the report in the Journal of the American Medical Assn. eliminated ear infections and exposure to loud noises in the environment as causes for the hearing loss, but could not identify a specific cause. A recent Australian study, however, found a 70% increased risk of hearing loss associated with the use of headphones to listen to portable music, and many experts suspect they are the primary cause of hearing loss in teens.
"Personal stereos are the most important change in the culture in the last 15 to 20 years," said Dr. Tommie Robinson Jr., president of the American Speech-Language-Hearing Assn. "Everybody has their own little device now, and how many times have you passed somebody and could hear their music?"
Even the relatively low level of damage found in the study can create problems.
"Just because a hearing loss is slight does not mean it is insignificant, particularly when it is in the high frequencies," said Dr. Alison Grimes, manager of the audiology clinic at Ronald Reagan- UCLAMedical Center.
In English, soft high-frequency sounds such as "s," "f," "th" and "sh" "carry a great deal of meaning, and are very important sounds to be able to discern," Grimes said. But those are the first to be lost, especially in a noisy environment like a classroom. "We know children have more difficulty learning and keeping up academically" when they can't hear well, she added.
Hearing loss can also affect social lives, because the teens may miss parts of conversations and punch lines, or may have to keep asking others to repeat things. "It may seem like they are not in touch, and kids are very aware when someone is a little different," said Dr. Gary C. Curhan of Brigham and Women's Hospital in Boston, a coauthor of the report.
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http://www.latimes.com/news/science/la-sci-teens-hearing-loss-20100818,0,559994.story
