Nearly 20 percent of people in their 20s already have some hearing loss, and more than half of people are not losing their hearing from loud noise at work, according to a new report.
The survey from the Centers for Disease Control and Prevention finds a surprising number of Americans have some hearing loss — and many don't even know it.
They may also not realize that everyday activities, such as mowing the lawn or even sitting for hours in loud traffic, could be damaging their hearing, the CDC said.
"Lots of people have hearing loss as a result of too much noise," acting CDC director Dr. Anne Schuchat told reporters.
"People as young as 20 to 29 years old already had noise-induced hearing damage."
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The CDC team got data from a large national survey of the health of Americans, and what they found surprised them. An estimated 40 million Americans under the age of 70 have hearing damage.
"About 53 percent of people ages 20-69 who have hearing damage from noise report no on-the-job exposure," the CDC said in a statement.
"About 24 percent of people ages 20-69 who report having excellent hearing have measurable hearing damage. About 20 percent of adults with no job exposure to loud sounds have hearing damage."
Hearing damage is permanent — there's no cure and no treatment. It results in more than people who don't hear well. It can also cause tinnitus, a constant ringing or buzzing in the ears, and the stress can lead to anxiety and high blood pressure.
A single, one-time loud noise can damage hearing, but so can noise at lower levels over time.
"The louder a sound is, and the longer you are exposed to it, the more likely it will damage your hearing," the CDC said.
It might not be a loud enough noise to register as dangerous, Schuchat said.
"More than half of those 40 million report no exposure to loud noise," she said. Loud concerts or constant pounding music are almost clichéd sources of hearing damage, but lawnmowers, leafblowers, woodworking saws and other machinery can also damage hearing.
"Even being stuck in traffic with horns blowing and sirens blaring can put hearing at risk," Schuchat said.
"People may not realize that these kinds of exposure can cause permanent damage."
Schuchat said most research has focused on hearing loss on the job, and employers seem to be doing a better job of helping workers protect their ears in noisy environments.
"The surprising result related to people who don't have work-related exposure to noise," she said.
So people should err on the side of caution when it comes to noise — using earplugs when operating equipment such as lawnmovers, moving away from constant loud noises, rolling up car windows in loud traffic and limiting time spent listening to loud music.
She said the CDC study couldn't answer specific questions about whether using ear buds was contributing to the problem, but said it's always a good idea to limit time and keep the volume as low as possible.
"Does everybody need to wear earplugs all day long, year in and year out? Of course not," Schuchat said.
"But if you know you are going to be in a noisy place, you can take steps to prepare for that."