Hearing loss due to exposure to loud noise or music through microphone has gone up by 15% from 1994 to 2006, according to an analysis of US data by researchers at the Harvard University. Researchers noted that while there was no significant increase in the rates of hearing loss, noise induced hearing loss among girls increased by 5%, which is very close to the level of boys.
Noise leads to hearing loss by damaging the sensory cells in the cochlea of the ear. It depends on the volume and the duration of exposure. Some people are more vulnerable to noise induced hearing loss than others.
Hearing tests conducted in 1988-94 showed that 18.5% teens suffered hearing loss by 19years. But this rate dropped down to 17.7% in 2005-08. This fall was despite the increase in the percentage of use of MP3 players and microphones. The damage caused due to loud MP3 players for longer durations might not show up right away. Elisabeth Henderson of Harvard University said, "Accumulated effects of exposure [to too-loud music] may cause hearing deficits eventually. Noise-induced damage might not be evident by 12 to 19 years of age, but might become increasingly evident in the mid-20s." The reports of the findings will be published in the January issue of 'Pediatrics'.