FRIDAY, March 18, 2011 (HealthDay News) -- Up to one-quarter of college students tested suffered from hearing loss, an unexpected finding that may be due to the use of personal music players such as MP3 players, according to a new study.
The research included 56 students, average age 21, who were asked to assess their own hearing and then underwent hearing tests. One-quarter of the students who believed they had normal hearing did not.
Instead, those students had 15 decibels or more of hearing loss at one or more test frequencies. While hearing loss at that level is not serious enough to require a hearing aid, the students' ability to learn could be affected. Among these students, 7 percent had 25 decibels or more of hearing loss, which is clinically diagnosed as mild hearing loss, said the University of Florida researchers.
The researchers were taken aback by the findings.
"You would expect normal hearing in that population," lead researcher Colleen Le Prell, an associate professor in the department of speech, language and hearing sciences, said in a university news release. "The criteria for normal hearing we used for the study were, we thought, extremely liberal criteria."
The students' hearing loss occurred in the range of frequencies important for speech discrimination, as well as in higher frequencies.
"With high-frequency hearing loss a person can miss a lot of subtle speech sounds, making it harder to discriminate different vowels or phonemes. It would also be much harder to hear sounds like bird songs or children's voices," explained Le Prell.
Some experts have suggested that increased rates of hearing loss in young adults may be due to the widespread use of personal music players. This study did find that the highest levels of high-frequency hearing loss were in male students who said they used personal music players.
The study was published recently in a special supplemental issue of the International Journal of Audiology.
The U.S. National Institute on Deafness and Other Communication Disorders outlines 10 signs of hearing loss.