5.38. Hearing Loss http://www.ck12.org
5.38 Hearing Loss
- Define deafness.
- Explain how loud sounds cause hearing loss.
- Describe how to prevent hearing loss caused by noise.
- Explain how hearing protectors work.
The noise of a cheering crowd at a game can be deafening! Really.
The Ear and Hearing
The ear is a complex organ that senses sound energy so we can hear.Hearingis the ability to sense sound energy
and perceive sound. All of the structures of the ear that are involved in hearing must work well for a person to have
normal hearing. Damage to any of the structures, through illness or injury, may cause hearing loss. Total hearing
loss is called deafness. To learn more about hearing loss, watch the animation at this URL: http://www.youtube.c
om/watch?v=YpIptQSEEjY.
Loud Sounds
The most common cause of hearing loss is exposure to loud sounds. Loud sounds can damage hair cells inside the
ears. Hair cells change sound waves to electrical signals that the brain can interpret as sounds. Louder sounds, which
have greater intensity than softer sounds, can damage hair cells more quickly than softer sounds. You can see the
relationship between sound intensity, exposure time, and hearing loss in the followingFigure5.75. The intensity of
sounds is measured in decibels (dB).
Q:What is the maximum amount of time you should be exposed to a sound as intense as 100 dB? What might make
a sound this intense?