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Teens aren’t always the best listeners but a new study shows that their hearing may not be to blame.

Despite the ubiquity of ear- and headphones for listening to music or cell phone conversations, a survey of more than 4300 12 to 19 year olds found no significant increase in hearing loss between 1988-1994 and 2005-2006. The study, which questioned adolescents about their exposure to loud noise or music through headphones in the previous 24 hours, found that 15.9% of teens experienced some change in their hearing between 1988-1994, while a similar 16.8% of adolescents showed the same shifts between 2005-2006.(More on Time.com: The Tricky Politics of Tween Bullying)

This lack of significant change in hearing occurred despite the fact that the teens also reported greater exposure to loud noises, either at concerts or other venues or through headphones; nearly 20% admitted to such exposure between in the first survey period compared to nearly 35% in the second survey. Interestingly, the scientists found that girls showed a greater prevalence of hearing changes than boys. Lead author Elisabeth Henderson of Harvard Medical School notes that there aren’t any obvious biological reasons for the gender difference. Rather, boys have traditionally had higher rates of hearing loss, possibly because of their exposure to environmental noise both in work and recreational settings, and these latest results may simply reflect the fact that changes in girls’ hearing are catching up to those of boys.

The results support the results of a previous study of teens surveyed in the 1990s that found headphone use was not strongly correlated to hearing loss, but that other factors, such as diet and nutritional deficiencies, may be contributing to hearing problems among youngsters. Other studies, however, have linked iPod and MP3 use to a blunting in hearing, and documented the fact that many teens listen to music at potentially damaging volumes. One survey advised using earphones for no more than 90 minutes a day at 80% volume. (More on Time.com: Think Your Kid's Physically Fit? Team Sports Don't Offer Nearly Enough Exercise)

Experts are particularly concerned about signs of hearing changes in teens because of permanent damage that excessive noise exposure can have. Once the sensitive cells deep in the ear that convert sound waves to electrical impulses are destroyed by loud noise, they cannot be restored.

In Henderson’s work, the greatest source of noise exposure came not from iPods or other mobile listening devices but from environmental sources such as music at concerts or clubs, and at certain work sites that rely on noisy machinery. “Noise levels at concerts and clubs can be very high – high enough to exceed Occupational Safety and Health Administration safety thresholds and much higher than the normal listening levels of a personal MP3 player,” she says. “It’s important for teens to realize that most musical artists and performers wear some form of hearing protection while onstage. Hearing protection is cheap and readily available at most pharmacies.” Even the simplest earplugs, she says, can lower noise exposure by 20 decibels and protect hearing cells from permanent damage.

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