Download HEALTHY CHOICES: Your Sense of Hearing

HEALTHY CHOICES:
Your Sense of Hearing
Ms. Mai
Lawndale High School
Your Sense of Hearing
Your ears are not only good for listening to
your favorite songs, but also for walking,
riding a bike, dancing, or any other activity
that requires balance
We just learned that our eyes receive light
rays and convert them to nerve impulses
that our brains interpret as sight
Our ears are very similar
The Structure and Function
Ears receive sound waves and convert them
into nerve impulses that our brain interprets
as sound
Specialized structures in our ear help
provide our sense of balance
Hearing
Your outer ear is shaped to collect sound
waves moving through air
The sound waves travel through a short
passageway called the external auditory canal
The external auditory canal is lined with hairs
and earwax to help prevent dirt, bacteria, and
other material from entering your ear
Outer Ear
The auditory canal ends at the eardrum,
which is a thin membrane across the
opening to the middle ear
The sound waves make the eardrum vibrate
Behind your eardrum are three tiny bones
(hammer, anvil, and stirrup)
Middle Ear
The middle ear is filled with air that enters
through the eustachian tube (connects the
middle ear with the back of the throat and
nose)
This connection keeps air pressure equal on
both sides of the eardrum so it does not
rupture when outside air pressure changes
like on an airplane or in an elevator
Inner Ear
When the stirrup vibrate, the oval window
also vibrates and passes on to a fluid in the
cochlea (spiral tube containing receptors
that sense vibration)
When the fluid vibrates, it moves the tiny
hairs lining the cochlea and changes the
vibrations into nerve impulses
Hearing
These nerve impulses travel along the
auditory nerve from the ear to the brain
As with the eye and vision, you do not hear
until the nerve impulses are interpreted by
your brain
The brain can tell which direction sound
wave are coming from each ear’s signals
travels to a different part of the brain
Anatomy of the Ear
Balance
If you have ever gotten dizzy, you are
experiencing movement in your
semicircular canals
Semicircular canals are curved tubes that
help provide your sense of balance, but play
no role in hearing
The semicircular canals are filled with fluid
and lined with tiny hairs so that when your
head moves, the fluid moves which causes
the hair to also move
Balance
The hairs are connected to nerve cells that send
impulses to the brain, which then interprets
and coordinates that information with impulses
from your eyes and your muscles
All this information tells you the position of
your body, how fast, and in which direction
Typically when people are dizzy, it is because
the fluids in their semicircular canals are still
moving
Common Ear Problems
Although the delicate parts of your ears are
enclosed within your skull, they can still be
damaged
Hearing loss from ear infections or other
factors are very common
Ear Infections
Ear infections occur when bacteria or
viruses travel from the nose or throat, up the
eustachian tube, and into the middle ear
Ear infections cause fluid or pus to collect
in the middle ear, which can distort or block
your hearing
Ear infections can be cured with antibiotics
One way to prevent ear infections is to blow
your nose gently
Hearing Loss
Hearing loss is caused by infections,
obstructions, or nerve damage
In severe middle-ear infections, the eardrum
can be damaged or even ruptured
If scars form while the eardrum if healing,
they will prevent the eardrum from vibrating
Severe infections can also damage the three
small bones in the middle ear, which can
cause permanent hearing loss
Hearing Loss
An obstruction in the ear blocks sound waves
An obstruction may be due to buildup of
wax or a bone blockage
Damage to nerve cells in the cochlea can
cause hearing loss
This type of damage may develop over time
and is usually caused by prolonged
exposure to loud sounds
Caring for your Ears
Ear infections should be treated promptly
because even a minor infection can lead to
hearing loss
Although some types of hearing loss cannot
be prevented, you can protect your ears
against nerve damage
General Care for your Ears
Never try to clean inside your ear with
Q-tips, hair pins, or other objects
Inserting objects into your ear can push wax
further into the canal and pack it against the
ear drum blocking your hearing, or puncture
the eardrum and allow infection to enter the
middle ear
You should only use washcloth to clean
your outer ear
Preventing Hearing Loss
The best way to prevent hearing loss from
nerve damage is to limit your exposure to loud
sounds (loud is anything above 85 decibels)
The length of time you are exposed to loud
sounds is as important as the loudness of the
sounds
Listening to music at 95 decibels for two or
three hours is as damaging as hearing a
much louder sound for only a short time
Sound Levels
Strategies For A Healthy Ear
Try to avoid noisy places. If you cannot, then wear ear plugs
when sounds become too loud. Ear plugs will not block out all
sound, but they will reduce the loudness to a safe level
If you have to be in noisy places often, give your ears a rest from
time to time by finding a quieter place
Keep the volume of stereos and radios turned down to a
comfortable level. If you listen through earphones, keep the
volume low enough so that you can still make out normal sounds
around you. If the earphones are drowning out all other
sounds, the volume is too high.