Prolonged listening at loud volume may lead to temporary and later irreversible loss, experts say
MONDAY, June 21 (HealthDay News) -- People using MP3 players are leaving themselves open to temporary changes in hearing, which over time might result in permanent hearing loss, Belgian researchers suggest.
Scientists already know that at work, exposure to harmful noise -- noise that is too loud or loud sounds that go on too long -- can eventually lead to hearing loss by damaging the sensitive hair cells in the inner ear. And the same may be true of loud music pumped directly into the ear through MP3 players, the researchers say.
For the study, a team led by Hannah Keppler from Ghent University exposed 21 people to rock music heard through headphones on an MP3 -- a digital audio player using MP3 files -- during six sessions. The participants used two types of headphones and several volume settings on an MP3 player.
The researchers tested the hearing of each person before and after each one-hour session.
Keppler's group found substantial, albeit temporary, changes in hearing sensitivity, which indicates the noise affects the ear's hair cells.
Permanent hearing loss "cannot be predicted from the initial temporary threshold shift [in hearing capacity], but considering the reduction in hearing sensitivity after listening to a portable media player, these devices are potentially harmful," the researchers concluded.
The findings are important because they document a troubling "temporary threshold shift" in hearing associated with MP3 players, said Robert Frisina, associate director of the International Center for Hearing & Speech Research at the University of Rochester Medical School in New York.
Combined with another study that shows temporary hearing loss can lead to permanent but delayed damage to hearing, the findings "become even more significant," he said.
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