Teenager wearing headphones

Hearing loss has increased about 30 percent (to about one in five) in United States teenagers from 1988 to 2006, studies suggest.

This hearing loss, experts believe, is not caused by an increase of loud noises or specific medications. Instead, the primary causes are believed to be due to lifestyle choices and habits, primarily the increased use of portable MP3 players.

For this study, researchers gathered information on 2,928 teens who completed a health survey sometime between 1988 and 1994.

The information from those adolescents was then compared to a group of 1,771 teenagers who took the same survey between 2005 and 2006.

From the first group of teenagers, hearing loss was reported at 14.9 percent in at least one ear. When compared with the more recent information, however, researchers explained an increase to 19.5 percent, or around 6.5 million teenagers.

Most hearing loss by teens in 2005-2006 was high frequency (16.4 percent), while only 9 percent experienced hearing loss at low frequencies.

Additionally, hearing loss in only one ear was more apparent when examining data from both groups.

Within the 2005-2006 group, hearing loss was 77 percent higher than the first group when expressed as “mild” or “worse.” Also, male teens were more likely to experience hearing loss.

Experts explain that listening to an MP3 player for an extended time (hours at a time) with loud volume, especially in the higher frequencies.

The way an MP3 file is compressed has changed, creating most music files to be significantly louder than they are actually meant to be.

Researchers suggest setting the volume on an MP3 device to a volume where a conversation can still be heard while listening to the device.