Research shows that teen girls are now suffering from hearing loss almost to the same degree as boys.

Up until now, teen boys have been more likely than girls to show signs of a particular type of hearing loss because boys are more likely to be exposed to loud noises from e.g. leaf-blowers, firearms, or work machines. But girls are catching up - and the ubiquity of portable audio players may be to blame, research suggests.

Research published in Pediatrics in January 2011 indicates that girls, who have typically lagged behind their male peers when it comes to excessive noise exposure, are catching up.

A study from Harvard's School of Public Health shows roughly 17% - or 1 in 6 - of teens of both sexes have a hearing loss, particularly in the area of mid- to high-frequency sounds that can make it harder for them to hear speech and some high-pitched sounds.

More use of music devices

The researchers, led by Harvard's Elisabeth Henderson, think that the increase in hearing loss in girls may be the result of increased use of portable music devices such as MP3 players and Ipods. Their data shows, that the number of teens who listen to music via headphones or ear buds in the course of 24 hours has increased from 20% in the late 1980s and early 1990s to 35% in more recent years.

To investigate whether the recent popularity of portable music players is affecting teens’ hearing, Henderson and her colleagues looked at hearing tests collected from 2,519 teenagers between 1988 and 1994, and 1,791 teenagers between 2005 and 2006.

Three types of hearing loss

The researchers considered three types of hearing loss: low-frequency loss, in which people struggle to hear sounds in the low end of the sound spectrum (such as parts of human speech); high-frequency hearing loss, which affects how well they hear high pitches (such as chimes or a microwave beep and kids' speech); and noise-induced hearing-threshold shifts, or "NITSs," in which people have trouble hearing sounds in the middle of the sound spectrum (which can include some human speech and higher-pitched sounds from musical instruments).

The investigators found, that all three types of hearing loss were generally as common in the recent group of teens as they had been during the previous survey. But when they looked more closely at the data, they saw that one group - teen girls - had experienced an increase in the rate of NITSs, from 12% in the first survey to 17% in the second.

Sources: www.reuters.com , www.aolhealth.com and www.ncbi.nlm.nih.gov