As sound enters the outer ear it is channeled down the
ear canal until it reaches the ear drum. The eardrum, a thin membrane
stretched over a tube, is moved by the sound waves. When the sound
vibrations reach the coiled, liquid filled tube called the cochlea,
thousands of hair cells in the cochlea translate these vibrations into
electrical impulses that are transmitted to the brain for
interpretation, Repeated
exposure to loud sounds can permanently damage the tiny hairs called
cilia. Once the cilia are damaged, they never grow back.
Continual, unprotected exposure to noises louder than 85 decibels (dB)
for 8 hours or more can be dangerous, and may result in hearing loss.
Permanent damage by sounds reaching over 100 dB or more, can occur in 2
hours or less. If you are exposed to loud and continuous sound for more
than fifteen
minutes per day at 100 to 110 dB, you need to wear hearing protection.
Even brief exposure to gun blasts or jet engine noise can cause pain
and permanent injury if your ears are not protected.
Hearing loss is cumulative and once lost, can never be regained. The
best way to protect your hearing is to create a habit of wearing
comfortable hearing protection. |
