You know what hearing is, but what is hearing loss?
-ment), happens when there is a problem with one or more parts of
the ear or ears. Someone who has hearing loss or impairment may be
able to hear some sounds or nothing at all. Impairment means
something is not working correctly or as well as it should. People
also may use the words deaf, deafness, or hard of hearing when
they're talking about hearing loss.
About 3 in 1,000 babies are born with hearing impairment, making
it the most common birth defect. A hearing problem can also develop
later in life. To understand how and why hearing loss happens, it
helps to know how the ear works.
How Hearing Works
The ear is made up of three different sections: the outer ear,
the middle ear, and the inner ear. These parts work together so you
can hear and process sounds. The outer ear, or
(the part you can see), picks up sound waves and the waves then
travel through the outer ear canal.
When the sound waves hit the eardrum in the middle ear, the
eardrum starts to vibrate. When the eardrum vibrates, it moves
three tiny bones in your ear. These bones are called the
(or incus), and
(or stapes). They help sound move along on its journey into the
The vibrations then travel to the
, which is filled with liquid and lined with cells that have
thousands of tiny hairs on their surfaces. There are two types of
hair cells: the outer and inner cells. The sound vibrations make
the tiny hairs move. The outer hair cells take the sound
information, amplify it (make it louder), and tune it. The inner
hair cells send the sound information to your hearing nerve, which
then sends it to your brain, allowing you to hear.
Types of Hearing Loss
There are a few different types of hearing loss:
, mixed (conductive and sensory combined), and
This happens when there is a problem with a part of the outer or
middle ear. Most kids with conductive hearing loss have a mild
hearing loss and it is usually temporary because in most cases
medical treatment can help.
This happens when the cochlea is not working correctly because
the tiny hair cells are damaged or destroyed. Depending on the
loss, a kid may be able to hear most sounds (although they would
be muffled); may be able to hear in quiet but not in noise; only
some sounds; or no sounds at all. Sensory hearing impairment is
almost always permanent and a kid's ability to talk normally
may be affected.
This happens when there is a problem with the connection from the
cochlea to the brain. Neural means related to nerve, so neural
hearing loss means the nerve that carries the messages from the
cochlea to the brain is damaged.
What Causes Hearing Loss?
Hearing loss can happen because a person was born with parts of
the ear that didn't form correctly and don't work well.
Other problems can happen later because of an injury or illness,
- middle ear fluid
- serious infections, such as meningitis
- head injury
- listening to very loud music, especially through
- repeated exposure to loud sounds, such as machinery
Lots of kids have had ear infections, which also can cause
hearing loss. Permanent hearing loss is rare from an ear infection,
but you need to visit the doctor if you or your parents suspect you
How Does a Doctor Test for Hearing Loss?
If a doctor thinks that a baby or child may have hearing loss,
the doctor will recommend that the parents take him or her to an
-luh-jist) is someone who is specially trained to test and help
with the problems related to hearing loss.
A pediatric audiologist tests a child's hearing by doing
different types of tests. They even have hearing tests for babies!
Maybe you've had a hearing test, when you wore headphones and
had to raise your left or right hand to show that you could hear in
If an audiologist finds that a child has hearing loss, he or she
will recommend treatment and suggest the family work with a special
team. This team can help figure out the best way for the kid to
learn and communicate.
How Is Hearing Loss Treated?
The kind of treatment depends on the type of hearing loss, how
severe it is, and the child's other needs. Common treatments
include medicine, operations, hearing aids, or assistive listening
devices, which emphasize voices and help kids hear better in noisy
settings. With treatment, most kids will be able to hear normally
Hearing aids are kind of like tiny amplifiers. They help someone
hear sounds better and can even pick up the sounds so that what
kids hear is more clear. Hearing aids deliver amplified sounds (via
sound vibrations) from the eardrum and middle ear to the inner ear
or cochlea. Hearing aid technology is available that can adjust the
volume of sounds automatically.
For some kids who are not able to hear or understand words even
with the help of hearing aids, there is a device called a
-plant). This is a very tiny piece of electronic equipment that is
put into the cochlea during an operation. It takes over the job of
the damaged or destroyed hair cells in the cochlea by turning
sounds into electrical signals that stimulate the hearing nerve
Learning and Communicating
A kid with hearing loss may attend a special school, special
classes within a regular school, or may be part of a regular
classroom. Depending on how severe their hearing loss is, some kids
may work with audiologists or speech-language pathologists to help
them develop their hearing and speaking skills. Some people with
hearing loss may need to use special techniques like these to
- speechreading, which involves looking closely at a
person's lips, facial expressions, and gestures to help
figure out spoken words
- American Sign Language, or ASL, which is a language of hand
movements that allows deaf people to communicate with one another
What about talking on the phone? Thanks to a telecommunication
device, also called a TDD, a conversation can be typed out instead
of spoken. The messages appear on a special screen or on a
You might wonder how a hearing-impaired person could see a movie
or watch TV. Closed-captioned TV shows and movies provide text at
the bottom of the screen, so people with hearing loss can read
along to follow the action.
So hearing-impaired kids can go to school, talk on the phone,
and watch a movie. If that sounds a lot like a typical kid's
life, you're right!
Robert C. O'Reilly, MD, and Thierry Morlet, PhD
Date reviewed: June 2006
Originally reviewed by:
Steven Dowshen, MD
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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