Loud noise is one of the most common causes of hearing loss. An estimated 26 million Americans between the ages of 20 and 69 already have irreversible hearing loss caused by loud sounds. And up to 16% of teens have hearing loss that may have been caused by loud noise. For adolescents, music players with headphones or earbuds are a common source of noise exposure.
How Noise Damages Hearing
“Noise damage can begin at any age, and it tends to accumulate over time. That’s why avoiding excess noise is so critical,” says Dr. Gordon Hughes, a clinical trials director and ear, nose, and throat specialist at NIH. “Hearing loss caused by noise is completely preventable.”
Noise-related hearing loss can arise from extremely loud bursts of sound, such as gunshots or explosions, which can rupture the eardrum or damage the bones in the middle ear. This kind of hearing loss can be immediate and permanent.
But most noise-related hearing problems develop slowly over time, with ongoing exposure to loud sounds. Loud noises can injure the delicate sensory cells—known as hair cells—in the inner ear. Hair cells help to convert sound vibrations into electrical signals that travel along nerves from the ear to the brain. These cells allow us to detect sounds. But when hair cells are damaged and then destroyed by too much noise, they don’t grow back. So hearing is permanently harmed.
How Loud is too Loud?
Sound is measured in units called decibels (dB). Sounds less than 75 dB are unlikely to harm hearing. Normal conversation, for instance, measures about 60 dB. A typical hair blow dryer has an intensity of about 85 dB, but if they’re used for just brief periods, they’re unlikely to damage hearing. However, long or repeated exposure to sounds at or above 85 dB can cause problems. The louder the sound, the quicker the damage.
“At maximum volume, an audio player with earbuds might produce 105 dB. There’s potential for noise damage to occur at barely 30 minutes of exposure,”
SOURCE:NIH News in Health