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-nih-tus), and it usually lasts until your ears gradually
readjust to normal sound levels. Experiencing tinnitus and 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 hair cells and inner hair cells). When the vibrations
move through the fluid, the tiny outer hair cells amplify the vibrations. The amplification
is important because it allows you to hear soft sounds, like whispering and birds.
Then, the inner hair cells translate the vibrations into electrical nerve impulses
and send them to the auditorynerve, 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: specific areas along the length of the cochlea
pick up gradually higher pitches.
Hearing 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
sounds seem quieter. 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. In many cases, hearing aids
can help the person hear normally.
In more severe cases, both outer and
inner hair cells aren't working correctly. This is also a type of permanent hearing
loss and usually people can benefit from cochlear implants. In some other cases, the
outer hair cells work correctly, but the inner hair cells or the nerve are damaged.
This type of hearing loss is called auditory neuropathy spectrum disorder.
The transmission of sound from the inner ear to the brain is then disorganized.
Children with auditory neuropathy spectrum disorder can develop strong language
and communication skills with the help of medical devices, therapy, and visual communication
Mixed hearing loss happens when someone has both conductive and
sensorineural hearing problems.
Central hearing loss happens when the cochlea is working properly,
but other parts of the brain are not. This is a less frequent type of hearing loss
and is more difficult to treat.
Auditory processing disorders (APD). This is not exactly a type
of hearing loss because someone with APD can usually hear well in a quiet environment.
But most people with APD have difficulty hearing in a noisy environment, which is
the usual environment we live in. In most cases, APD can be treated with proper therapy.
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 happens 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 37.5 million American people aged 18 and over are deaf or hearing impaired.
That's about 15 out of every 100 people. Another 26 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
Sensorineural hearing impairment results from problems with or damage to the inner
ear or the auditory nerve. Its causes include:
disorders. Some genetic (inherited) disorders interfere
with the proper development of the inner ear and/or 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
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 hair cells in
the cochlea, which then can't transmit sounds as effectively as they did before.
The outer hair cells are usually affected first, because they're very sensitive
to loud sounds. Remember that these cells help us hear soft sounds. If exposure to
loud noise continues for long periods of time, the inner hair cells and even the auditory
nerve can become affected.
How Do Doctors Diagnose It?
Hearing loss can be difficult to diagnose in infants and babies because they haven't
yet developed communication skills. All 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, or has a delay
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
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. For other tests, the audiologist will place a small probe at the entrance
of the ear canal and record tiny responses from the cochlea. The audiologist can also
study how the brain reacts to sounds by placing electrodes (small stickers) on the
scalp. Some other tests will require the person to indicate what they heard when the
audiologist is playing sounds or words, in quiet or in the presence of a background
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 300,000 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 in the United States 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, hearing loss
caused by loud noise can be prevented, and prevention efforts can
start at any age (even in teens). 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
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.)
If you feel your hearing
is different after being at an event with a lot of noise (for example, you need
to ask people to repeat what they're saying), it means you're probably experiencing
a temporary hearing loss due to noise. Don't worry, it will go away (usually after
a good night's sleep), but it means that next time you want to participate in the
same event, you should wear protection for your ears to avoid a permanent hearing
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
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, Cued Speech, or other sign languages,
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.