Hearing loss, or hearing impairment (say: im-pare-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.

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 pinna (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 hammer (or malleus), anvil (or incus), and stirrup (or stapes). They help sound move along on its journey into the inner ear.

The vibrations then travel to the cochlea, 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.

There are a few different types of hearing loss: conductive, sensory, mixed (conductive and sensory combined), and neural.

• Conductive hearing loss is caused by damage to the outer or middle ear. With a conductive loss, sound waves are blocked as they move through the outer or middle ear. Since the sound cannot be conducted efficiently, the sound energy that reaches the inner ear is weaker or softer. A conductive loss can result from infection, excessive earwax buildup, fluid in the middle ear, damage to the middle ear bones, a perforation of the eardrum or a foreign body in the ear canal.
  
  Signs/symptoms may include:
  • Perceiving speech and other sounds as faint or muffled
  • Ear pain or discharge from the ear
  • Redness or swelling of the outer ear
  • Pressure or fullness in the ear
• Sensorineural hearing loss is caused by damage to the inner ear. Sound waves travel normally through the outer and middle ear, however, the inner ear is unable to pick up the vibrations or is unable to send the vibrations to the brain. Also called "nerve deafness", it usually occurs in both ears. A sensorineural loss can result from infection, disease, certain drugs, excessive noise, birth defects and aging.
  
  Signs/symptoms may include:
  • Perceiving speech and other sounds as distorted or unclear
  • Difficulty hearing certain pitches (usually high pitches)
  • Hearing a ringing or buzzing sound that is constant or periodic
  • Difficulty understanding speech in the presence of background noise
• Mixed hearing loss is caused by damage to the outer/middle ear and the inner ear. Typically, sound waves are not conducted efficiently to the inner ear, and once they reach the inner ear the vibrations cannot be picked up or sent to the brain. Therefore, a mixed hearing loss is the combination of a conductive and sensorineural hearing loss.
  
  Signs/symptoms may include:
  See "Signs/Symptoms" under Conductive hearing loss & Sensorineural hearing loss.
• Central hearing loss is caused by damage to the auditory nerve or hearing centers. Sound waves are transmitted normally through all three parts of the ear, however, the auditory nerve may not be able to send the electrical impluses to the brain or the hearing centers of the brain may not receive the signals correctly. A Central loss can result from head injuries, disease or tumors.
  
  Signs/symptoms may include:
  Detecting sound but not being able to understand or process it

• Difficulty hearing conversations, especially in the presence of background noise
• Frequently asking people to repeat what they have said
• Misunderstanding what someone has said
• Difficulty hearing on the telephone
• Requiring the TV or radio volume to be louder than preferred by others in the room
• Feeling that people are mumbling when they are talking
• Difficulty hearing certain sounds or pitches
• Agreeing or nodding your head during conversations when you are uncertain of what has been said
• Removing yourself from conversations because it is too difficult and taxing to hear
• Reading people's lips in order to follow what they are saying
• Straining to hear or keep up with a conversation

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, including:

• middle ear fluid
• serious infections, such as meningitis
• head injury
• listening to very loud music, especially through headphones
• 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 have one.

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 audiologist. An audiologist (say: awd-ee-ah-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 each ear.

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.

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 again.

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 cochlear implant (say: ko-klee-ur im-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 directly.

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 communicate:

• 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 without speaking

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 printout.

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!

Hearing Protection Tips

If you have 100-percent of your hearing or close to it, you need to protect your ears properly to keep it intact. There are various pieces of hearing equipment made to protect your ears from dangers such as high wind and cold, water, noise, dirt, and also from other people and objects while playing various sports.

Here are a few hearing protection tips:

• Make sure that your ears are always properly covered by a hat or ear muffs in the cold, rain and wind. This will keep your ears and ear canals both warm and dry.
• Make sure you wear ear plugs or ear muffs when you are subjected to loud, constant and monotonous noises. These types of noises are commonly heard in factories, on construction sites, at airports, at rock concerts and in various sporting activities such as motorcycle racing, car racing and on shooting ranges.
• You should also wear the proper protective gear for your head and ears while competing in sports such as ice hockey, rugby, football, fencing, boxing, lacrosse, hunting and various forms of martial arts.
• You should also protect your ears from excessive noise when using items such as lawn mowers, drills and other power tools.
• If you are a musician, you should also look into getting yourself specially made musician's earplugs as loud music can often lead to hearing loss.
• Remember to keep your television set, computer, radios and other audio devices at a respectable level of volume.
• Make sure your hearing protection fits. Hearing protection equipment won't protect your hearing if they aren't covering your ears properly.

Hearing loss is often permanent, so it's worth investing a few dollars into the proper type of hearing protection devices. Make sure your hearing protection devices are designed for what you are using them for and make sure they are comfortable and fit you properly.