Hearing Protection

How can noise damage our hearing?

Hearing is a complex process that works like this: Sound waves enter the outer ear and travel through the ear canal to the ear drum. The ear drum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. The bones in the middle ear couple the sound vibrations from the air to fluid vibrations in the cochlea of the inner ear, which is shaped like a snail and filled with fluid. Once the vibrations cause the fluid inside the cochlea to ripple, a traveling wave forms along the basilar membrane. Hair cells—sensory cells sitting on top of the basilar membrane—ride the wave. As the hair cells move up and down, microscopic hair-like projections (known as stereocilia) that perch on top of the hair cells bump against an overlying structure and bend, creating an electrical signal. The auditory nerve then carries this electrical signal to the brain, which translates it into a sound that we recognize and understand.

Hearing loss due to noise exposure can be caused by a one-time exposure to a loud sound or repeated exposure to sounds at various loudness levels over an extended period of time.

The following are some warning signs of the presence of or exposure to hazardous levels of noise:

  • You can't hear someone talking three feet away.
  • You have a feeling of “fullness” in your ears after leaving a noisy area.
  • You hear ringing or buzzing (tinnitus) in your ears immediately after exposure to noise.