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“SENSE”sational
Facts About Hearing Loss
Like
your other sense organs, your ears are extremely well-designed.
In fact, they serve two very important purposes. Do you know what
they are? You were probably able to figure out that your ears
help you to hear sounds, but what you probably did not know is
that your ears also help you to keep your balance.
How
You Hear
The
hearing process is not simple at all. When an object makes a noise,
it sends vibrations (better known as sound waves) speeding through
the air. These vibrations are then funneled into your ear canal
by your outer ear. As the vibrations move into your middle ear,
they hit your eardrum and cause it to vibrate as well. This sets
off a chain reaction of vibrations. Your eardrum, which is smaller
and thinner than the nail on your pinky finger, vibrates the three
smallest bones in your body: first, the hammer, then the anvil,
and finally, the stirrup. The stirrup passes the vibrations into
a coiled tube in the inner ear called the cochlea. The fluid-filled
cochlea contains thousands of hair-like nerve endings called cilia.
When the stirrup causes the fluid in the cochlea to vibrate, the
cilia move. The cilia change the vibrations into messages that
are sent to the brain via the auditory nerve. The auditory nerve
carries messages from 25,000 receptors in your ear to your brain.
Your brain then makes sense of the messages and tells you what
sounds you are hearing.
How
You Keep Your Balance
Near
the top of the cochlea are three loops called the semi-circular
canals. The canals are full of liquid also. When you move your
head, the liquid moves. It pushes against hair like nerve endings,
which send messages to your brain. From these messages, your brain
can tell whether or how your body is moving.
If you
have ever felt dizzy after having spun around on a carnival ride,
it was probably because the liquid inside the semicircular canals
swirled around inside your ears. This makes the hairs of the sensory
cells bend in all different directions, so the cells' signals
confuse your brain.
What
Did You Say?
Did
you know that some people have trouble hearing and others cannot
hear at all? Well it's true. When a person can't hear well, a
hearing aid can sometimes help them hear better. However, people
who are entirely deaf have to rely on all their other senses to
help process all of the information from the world around them.
They are deaf because of an illness or they were born that way.
You can also lose your ability to hear at an early age by listening
to things that are very loud. Scientists measure loudness in decibels.
Below is a table of various noises and their decibel level.
Noise Decibels
| Whisper...................... |
20 |
| Normal
Talking.......... |
50-60 |
| Car
Traffic.................. |
70 |
| Alarm
Clock............... |
80 |
| Lawn
Mower.............. |
95 |
| Rock
Concert............. |
100 |
| Jackhammer............. |
115 |
| Jet
Engine................ |
130 |
| Gun
Shot.................. |
140 |
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