Just one hour`s listening to an MP3 player can damage hearing. It causes temporary changes in hearing sensitivity which may lead to long-term harm, say scientists.
A new study reveals that over-stimulation of hair cells within the ear occurs even at varying volume levels for short periods of time. Listening to music at high volume causes temporary changes in hearing sensitivity which may lead to long-term harm, reports dailymail.co.uk.
The new study follows previous warnings from doctors that using MP3 players at high volumes with earphones that fit into the ear canal could lead to loss of hearing.
The new study was conducted by researchers of Ghent University, Belgium. The volunteers were divided in two groups -- one group consisted of 21 people aged 19 to 28 years and they were exposed to pop and rock music using MP3 players at varying volumes for one hour.
The second group of 28 men and women were a control group who were not exposed to MP3 music.
Hearing tests were carried out before and after the exposure, which found significant threshold or emission shifts were observed between almost every session of the noise exposure group compared with the control group.
"It is well known that excessive occupational noise exposure can lead to noise-induced hearing loss. Excessive noise exposure can lead to metabolic and mechanical effects resulting in alterations of the structural elements of the inner ear that contains auditory sensory cells or hair cells," said lead researcher Hannah Kempler.
"The primary damage is concentrated on the outer hair cells, which are more vulnerable to acoustic over-stimulation than inner hair cells. Considering the reduction in hearing sensitivity after listening to a portable media player, these devices are potentially harmful," she added.
Emma Harrison, director of Royal National Institute for the Deaf (RNID), Britain, says that long term exposure to loud music can cause permanent deafness.
"RNID research shows that 66 percent of personal music player users are listening to music at louder than 85 decibels, which according to the World Health Organisation, can cause permanent hearing damage over time," Harrison said.
The European Commission has warned up to 10 percent of 30-year-olds would have to wear a hearing device within the next decade because they listen to music too loudly through headphones.
Surveys showed that more than 90 percent of young people in Europe and the US used MP3 players, often for several hours a day at maximum volume.
"Many people regularly use personal music players and are often not aware that they could be putting their hearing at risk. It is crucial that manufacturers and legislators are supportive of these plans and work together to protect the hearing of a generation of music lovers," she said.
The study was published in the Archives of Otolaryngology - Head & Neck Surgery journal.
BDST: 1259 HRS, June 24, 2010
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