Their parents may have suspected it now it's been proven. Personal stereos can damage the hearing of young people, especially if they have a history of childhood ear illnesses.
French researchers discovered the extent of this problem when they looked at medical assessments of 18-24 year olds from army selection centres.
The single greatest factor in hearing loss was the use of personal stereos for more than one hour a day, but it only seemed to affect those who had suffered persistent otitis media, or glue ear, as children.
Young people who had no childhood ear problems were not affected by the regular use of their personal stereos.
Other activities that affected hearing levels included regularly attending rock concerts and discos (Lancet, 1999; 353: 35).