(RxWiki News) It's a familiar scene: a teenager on the bus pulls out an mp3 player, throws on a pair of headphones, and cranks the volume.
The music can be heard through the headphones from ten feet away. It's not far-fetched to ask: does that lead to hearing damage?
In a recent study, researchers at Harvard set out to answer that question. The study, which appears in the January issue of the journal Pediatrics, analyzes hearing test results from 4,310 adolescents between 12 and 19 years of age. Examining this data from National Health and Nutrition Examination Surveys from 1988-1994 and 2005-2006, the researchers studied trends in noise-induced threshold shifts (NITs), high-frequency hearing loss (HFHL), and low-frequency hearing loss (LFHL).
Exposure to loud noise commonly causes a ringing sound within the human ear. This ringing, called tinnitus, can be caused by even short bursts of loud sound but usually happens after a longer duration of exposure. Over time, frequent exposure to loud noise can lead to noise-induced hearing loss (NIHL).
The Harvard researchers found that, with the exception of one subset, the rates of hearing loss did not change between the periods of 1988-1994 and 2005-2006, even though exposure to loud sound grew from 19.8 percent to 34.8 percent. The exception was found in females from the sample population. The authors found that the rate of noise-induced threshold shifts (a type of hearing loss caused by exposure to loud noise) in female adolescents grew from 11.6 percent to over 16 percent between the two time periods.
Although the findings might indicate that a growing exposure to loud noise through headphones has led to hearing loss in adolescent females, the authors say their results do not point to headphone use as the culprit. They admit that their study does not explain for the increased hearing loss in females, but that it is likely due to factors not included in the questionnaire.
Even though this study did not find a shocking increase in hearing loss rates, the authors advocate for improved education about the hazards of overexposure to loud noise. They add that while loud noise may not cause hearing loss immediately, it can lead to irreparable ear damage and hearing loss further down the road. Just ask Pete Townsend.