what is hearing loss?

You know what hearing is, but what is hearing loss? 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 three in 1,000 babies are born with hearing impairment, making it one of the most common birth defects. 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 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. The sound vibrations make the tiny hairs move. The hairs then change the sound vibrations into nerve signals, so your brain can interpret the sound.

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

Conductive (say: kun-duk-tiv) hearing loss: 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.

Sensory (say: sen-suh-ree) hearing loss: 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); 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.

Neural (say: nur-ul) hearing loss: 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, 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.