What's the Buzz?
Have you ever heard a ringing or buzzing sound in your ears
after going to a party, concert, or other really loud event? This
condition is called
tinnitus
(pronounced: tih-
neye
-tus), and it usually lasts until your ears gradually readjust to
normal sound levels. Experiencing tinnitus or having to yell to be
heard are both signs that the environment you're in is too
loud.
Going to concerts or blasting your stereo once in a while is
common. But over time, too much exposure to loud noise can lead to
a condition known as
noise-induced hearing loss
(NIHL)
. Personal music players are among the chief culprits of NIHL among
teens. Video games, television sets, movie theaters, traffic, and
some machines and appliances can also make the environment too
noisy for the average person. In fact, many experts believe that
people are losing their hearing at much younger ages than they did
just 30 years ago.
In addition to noise-induced hearing loss, other types of
hearing impairment can affect people during their teen years.
Unlike hearing loss that's caused by noise, though, these types
of hearing loss are not preventable.
Some people are born with hearing impairment - and kids and
teens can lose their hearing for many reasons. If you don't
know anyone who is deaf or hearing impaired, chances are you will
someday. So what causes hearing impairment, and what it's like
to live without being able to hear in a world full of sounds?
How the Ear Hears
Think about how you can feel speakers vibrate on your sound
system or feel your throat vibrate when you speak. Sound, which is
made up of invisible waves of energy, causes these vibrations.
Hearing begins when sound waves that travel through the air
reach the outer ear or
pinna
, which is the part of the ear you can see. The sound waves then
travel from the pinna through the ear canal to the middle ear,
which includes the
eardrum
(a thin layer of tissue) and three tiny bones called
ossicles
. When the eardrum vibrates, the ossicles amplify these vibrations
and carry them to the inner ear.
The inner ear is made up of a snail-shaped chamber called the
cochlea
(pronounced:
ko
-klee-uh), which is filled with fluid and lined with thousands of
tiny hair cells (outer and inner rows). When the vibrations move
through this fluid, the tiny hair cells translate them into
electrical nerve impulses and send them to the
auditory
nerve
, which connects the inner ear to the brain. When these nerve
impulses reach the brain, they are interpreted as sound. The
cochlea is like a piano so that specific areas along the length of
the cochlea pick up gradually higher pitches.
This may seem like a long process, but it happens almost
instantly. The school bell rings and you know you need to get to
your next class. The phone rings and you automatically pick it up.
You hear a question and immediately respond to it. But in reality,
every time you hear a sound, the various structures of the ear have
to work together to make sure the information gets to your
brain.
What Is Hearing Impairment?
Hearing impairment occurs when there's a problem with or
damage to one or more parts of the ear.
-
Conductive hearing loss
results from a problem with the outer or middle ear, including
the ear canal, eardrum, or ossicles. A blockage or other
structural problem interferes with how sound gets conducted
through the ear, making sound levels seem lower. In many cases,
conductive hearing loss can be corrected with medications or
surgery
.
-
Sensorineural
(pronounced: sen-so-ree-
nyour
-ul)
hearing loss
results from damage to the inner ear (cochlea) or the auditory
nerve. The most common type is caused by the outer hair cells not
functioning correctly. The person has trouble hearing clearly,
understanding speech, and interpreting various sounds. This type
of hearing loss is permanent. It may be treated with hearing aids
or, in severe cases, a cochlear implant.
-
Mixed hearing loss
occurs when someone has both conductive and sensorineural hearing
problems.
The degree of hearing impairment can vary widely from person to
person. Some people have partial hearing loss, meaning that the ear
can pick up some sounds; others have complete hearing loss,
meaning that the ear cannot hear at all (people with complete
hearing loss are considered deaf). In some types of hearing loss, a
person can have much more trouble when there is background noise.
One or both ears may be affected, and the impairment may be worse
in one ear than in the other.
The timing of the hearing loss can vary, too.
Congenital
hearing loss is present at birth.
Acquired
hearing loss occurs later in life - during childhood, the teen
years, or in adulthood - and it can be sudden or progressive
(happening slowly over time).
According to the National Institute on Deafness and Other
Communication Disorders, about 28 million Americans are deaf or
hearing impaired. That's about 1 out of every 10 people.
Another 30 million are exposed to hazardous noise levels on a
regular basis. Hearing loss is also the most common birth
anomaly.
What Causes Hearing Impairment?
The most common cause of conductive hearing loss in kids and
teens is
otitis
(pronounced: o
-tie-
tus)
media
, which is the medical term for an ear infection that affects the
middle ear. Ear infections cause a buildup of fluid or pus behind
the eardrum, which can block the transmission of sound. Even after
the infection gets better, fluid might stay in the middle ear for
weeks or even months, causing difficulty hearing. But this fluid is
usually temporary, and whether it goes away on its own (which is
usually the case) or with the help of medications, once it's
gone a person's hearing typically returns to normal. Blockages
in the ear, such as a foreign object, impacted earwax or dirt, or
fluid due to
colds
and
allergies
, can also cause conductive hearing loss.
People also get conductive hearing loss when key parts of the
ear - the eardrum, ear canal, or ossicles - are damaged. For
example, a tear or hole in the eardrum can interfere with its
ability to vibrate properly. Causes of this damage may include
inserting an object such as a cotton swab too far into the ear, a
sudden explosion or other loud noise, a sudden change in air
pressure, a head injury, or repeated ear infections.
Sensorineural hearing impairment results from problems with or
damage to the inner ear or the auditory nerve. Its causes
include:
-
Genetic disorders
.
Some genetic (inherited) disorders interfere with the proper
development of the inner ear and the auditory nerve.
-
Injuries to the ear or head.
Injuries such as a skull fracture can cause hearing loss.
-
Complications during pregnancy or birth.
Some babies are born with hearing impairment due to infections or
illnesses that the mother had while she was pregnant, which can
interfere with the development of the inner ear. Premature babies
are also at higher risk for hearing impairment.
-
Infections or illnesses.
Certain conditions, such as repeated ear infections, mumps,
measles, chickenpox, and brain tumors, can damage the structures
of the inner ear.
-
Medications.
Certain medications, such as some antibiotics and
chemotherapy
drugs, can cause hearing loss.
-
Loud noise.
A sudden loud noise or exposure to high noise levels (such as
loud music) over time can cause permanent damage to the tiny
hairs in the cochlea, which then can't transmit sounds as
effectively as they did before.
How Do Doctors Diagnose It?
Hearing loss can be difficult to diagnose in infants and babies
because they haven't yet developed communication skills. Often
babies are screened before they leave the hospital to see if they
have hearing loss. Sometimes parents may begin to notice that the
baby doesn't respond to loud noises or to the sound of
voices.
Certain symptoms in teens should prompt a trip to the doctor.
According to the American Speech-Language-Hearing Association, you
should let your parents or doctor know if:
- You feel that people mumble or that their speech is not
clear, or you hear only parts of conversations when people are
talking.
- You often ask people to repeat what they said.
- Friends or family tell you that you don't seem to hear
very well.
- You don't laugh at jokes because you miss too much of the
story.
- You need to ask others about the details of a class or
meeting you attended.
- People say that you play music or your TV too loudly.
- You can't hear the doorbell or telephone.
The doctor will do an ear exam and, if necessary, refer someone
with these symptoms to an
audiologist
, a health professional who specializes in diagnosing and treating
hearing problems. The audiologist will do various hearing tests
that can help detect where the problem might be. For example, to
test the function of the inner ear, the audiologist can put a
special device behind the ear that transmits tones directly there.
This helps to distinguish between inner ear and middle or outer ear
problems.
A person may also need to see an
otolaryngologist
(pronounced: o-toe-lar-en-
gah
-luh-jist), a doctor who specializes in ear, nose, and throat
problems.
How Is It Treated?
Treatment for hearing loss varies depending upon the cause of
the hearing impairment. Treatment may involve removing wax or dirt
from the ear or treating an underlying infection. If there is
damage or a structural problem with the eardrum or ossicles,
surgery may help to repair it. If the problem is with the cochlea
or hearing nerve, a hearing aid or cochlear implant may be
recommended.
Hearing aids come in various forms that fit inside or behind the
ear and make sounds louder. They are adjusted by the audiologist so
that the sound coming in is amplified enough to allow the person
with a hearing impairment to hear it clearly. Sometimes, the
hearing loss is so severe that the most powerful hearing aids
can't amplify the sound enough. In those cases, a cochlear
implant may be recommended.
Cochlear implants are surgically implanted devices that bypass
the damaged inner ear and send signals directly to the auditory
nerve. A small microphone behind the ear picks up sound waves and
sends them to a receiver that has been placed under the scalp. This
receiver then transmits impulses directly to the auditory nerve.
These signals are perceived as sound and allow the person to
hear.
Depending upon whether someone is born without hearing (
congenital deafness
) or loses hearing later in life (after learning to hear and speak,
which is known as
post-lingual deafness
), medical professionals will determine how much therapy the person
needs to learn to use an implant effectively. Many people with
implants learn to hear sounds effectively and even use the
telephone.
More than 65,000 people around the world have received cochlear
implants and about one third of them are children.
Some patients with hearing loss and their families may decide
not to restore hearing. This is particularly true of children whose
parents are hearing impaired and want their children to be able to
function in the deaf community. The language of the deaf community
is American Sign Language (ASL). ASL is a system of gestures many
deaf and hearing-impaired people use to communicate.
Can I Prevent Hearing Impairment?
Many cases of hearing loss or deafness are not preventable;
however, it is very important to realize that hearing loss caused
by loud noise can be prevented. The only cause that can be
prevented is noise-induced hearing loss. There are steps you can
take to reduce your risk of this type of hearing loss.
The intensity of sound is measured in units called
decibels
, and any sounds over 80 decibels are considered hazardous with
prolonged exposure. These include things like loud music, sirens
and engines, and power tools such as jackhammers and leaf
blowers.
To reduce the risk of permanent hearing damage, you can:
- Turn down the volume on your stereo, TV, and especially the
headset on your music player.
- Wear earplugs if you're going to a loud concert or other
event (you'll still hear the music). Special protective
earmuffs are a good idea if you operate a lawn mower or leaf or
snow blower, or at a particularly loud event, like a car race.
(Cotton in the ear doesn't provide enough protection.)
- See your doctor right away if you suspect any problems with
your hearing, and get your hearing tested on a regular
basis.
What's Life Like for People Who Are Hearing Impaired?
For people who lose their hearing after learning to speak and
hear, it can be difficult to adjust because hearing has been an
essential aspect of their communication and relationships. The good
news is that new technologies are making it possible for more
hearing-impaired teens to attend school and participate in
activities with their hearing peers. These technologies include
programmable hearing aids, which teens can adjust for different
environments; FM systems, which include a microphone/ transmitter
worn by the teacher and a receiver worn by the student; cochlear
implants; real-time captioning of videos; and voice-recognition
software, which can help with note taking.
Many hearing-impaired teens read lips and use ASL, and in some
cases an interpreter may be available to translate spoken language
in the classroom. Some teens may attend a separate school or
special classes offered within a public school. And for
hearing-impaired people who want to go to college, many
universities in the United States will accommodate their needs. One
college, Gallaudet University, in Washington, DC, is dedicated
entirely to hearing-impaired students.
At home, devices such as closed-captioned TVs, lights that flash
when the doorbell or phone rings, and telephones with digital
readout screens (called telecommunications devices for the deaf, or
TDDs) are often helpful. Family and friends of people who use ASL
or lip reading can help by learning to use sign language or, if the
person uses lipreading, by speaking slowly, clearly, and face to
face.
Reviewed by:
Robert C. O'Reilly, MD, and Thierry Morlet, PhD
Date reviewed: June 2006
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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