One in five teenagers suffer from at least slight hearing loss, a significant rise from a decade ago, when the rate was only one in seven.

The new study, published Wednesday in The Journal of the American Medical Association, analyzed data on about 1,771 youngsters aged 12 to 19 who participated in the National Health and Nutrition Examination Survey of 2005-6, and compared the prevalence of hearing loss with that of youngsters who took part in the survey in 1988-94.

The percentage with at least slight hearing loss increased by 30 percent, to 19.5 percent from 14.9 percent in the earlier study. For most the hearing loss is slight enough they may not even notice.

The number with greater hearing loss  called mild hearing loss  has also increased, from 1 in 30 teenagers a decade ago to 1 in 20 teens in 2005-6, the study found. With mild hearing loss, one might not be able to hear a person whispering in one’s ear.