Diseases & Conditions

Hearing loss

The gradual hearing loss that occurs as you age (presbycusis) is a common condition. An estimated one-quarter of Americans between the ages of 65 and 75 and around three-quarters of those older than 75 have some degree of hearing loss.

Over time, the wear and tear on your ears from noise contributes to hearing loss by damaging your inner ear. Doctors believe that heredity and chronic exposure to loud noises are the main factors that contribute to hearing loss. Other factors, such as earwax blockage, can prevent your ears from conducting sounds as well as they should.

You can't reverse hearing loss. However, you don't have to live in a world of quieter, less distinct sounds. You and your doctor or hearing specialist can deal with hearing loss by taking steps to improve what you hear.

How you hear
Hearing occurs when sound waves reach the structures inside your ear, where the sound wave vibrations are converted into nerve signals that your brain recognizes as sound.

Your ear consists of three major areas: the outer ear, middle ear and inner ear. Sound waves pass through the outer ear and cause vibrations at the eardrum. The eardrum and three small bones of the middle ear — the hammer, anvil and stirrup — amplify the vibrations as they travel to the inner ear. There, the vibrations pass through fluid in the cochlea, a snail-shaped structure in the inner ear. Attached to nerve cells in the cochlea are thousands of tiny hairs that help translate sound vibrations into electrical signals that are transmitted to your brain. The vibrations of different sounds affect these tiny hairs in different ways, causing the nerve cells to send different signals to your brain. That's how you distinguish one sound from another.

What causes hearing loss
For some people, the cause of hearing loss is the result of a gradual buildup of earwax, which blocks the ear canal and prevents conduction of sound waves. Earwax blockage is a cause of hearing loss among people of all ages.

Most hearing loss results from damage to the cochlea. Tiny hairs in the cochlea may break or become bent, and nerve cells may degenerate. When the nerve cells or the hairs are damaged or missing, electrical signals aren't transmitted as efficiently, and hearing loss occurs. Higher pitched tones may become muffled to you. It may become difficult for you to pick out words against background noise.

Ear infection and abnormal bone growths or tumors of the outer or middle ear can cause hearing loss. A ruptured eardrum also may result in loss of hearing.

Talk to your doctor if you have difficulty hearing. Your hearing may have deteriorated if you find that it's harder to understand everything that's said in conversation, especially when there's background noise, if sounds seem muffled, or if you find yourself having to turn the volume higher when you listen to music, the radio or television.

At first, your doctor may perform a general screening test to get an overall idea of how well you can hear. Your doctor may ask you to cover one ear at a time to see how well you hear words spoken at various volumes and how you respond to other sounds.

To determine your ability to hear and the extent of your hearing loss, your doctor may refer you to a hearing specialist (audiologist) for hearing tests.

During more thorough testing conducted by an audiologist, you wear earphones and hear sounds directed to one ear at a time. The audiologist presents a range of sounds of various tones and asks you to indicate each time you hear the sound. Each tone is repeated at faint levels to find out when you can barely hear. The audiologist will also present various words to determine your hearing ability.

Hearing loss treatment depends on the cause and severity of your hearing loss.

If your hearing loss is due to damage to your inner ear, a hearing aid can be helpful by making sounds stronger and easier for you to hear. If you can't hear well because of earwax blockage, your doctor can remove the wax and improve your hearing. If you have severe hearing loss, a cochlear implant may be an option for you.

Removing wax blockage
Earwax blockage is a common reversible cause of hearing loss. Your doctor may remove earwax by:

• Loosening the wax. Your doctor uses an eyedropper to place a few drops of baby oil, mineral oil or glycerin in your ear to loosen the wax, then squirts warm water into your ear using a bulb syringe. As you tilt your ear, the water drains out. Your doctor may need to repeat the process several times before the wax eventually falls out.
• Scooping out the wax. Your doctor may loosen the wax, and then scoop it out with a small instrument called a curette.
• Suctioning out the wax. Your doctor uses a suction device to remove the softened wax.

Hearing aids
An audiologist can discuss with you the potential benefits of using a hearing aid, recommend a device and fit you with it.

Hearing aids can't help everyone with hearing loss, but they can improve hearing for many people. The components of a hearing aid include:

• A microphone to gather in the sounds around you
• An amplifier to make sounds louder
• An earpiece to transmit sounds to your ear
• A battery to power the device

The louder sounds help stimulate nerve cells in the cochlea so that you can hear better. Getting used to a hearing aid takes time. The sound you hear is different because it's amplified. You may need to try more than one device to find one that works well for you. Most states have laws requiring a trial period before you buy a hearing aid, making it easier for you to decide if the hearing aid helps.

Hearing aids come in a variety of sizes, shapes and styles. Some hearing aids rest behind your ear with a small tube delivering the amplified sound to the ear canal. Other styles fit in your outer ear or within your ear canal.

Cochlear implants
If your hearing loss is more severe, often due to damage to your inner ear, an electronic device called a cochlear implant may be an option. Unlike a hearing aid that amplifies sound and directs it into your ear canal, a cochlear implant compensates for damaged or nonworking parts of your inner ear. If you're considering a cochlear implant, your audiologist, along with a medical doctor who specializes in disorders of the ears, nose and throat (ENT), will likely discuss the risks and benefits with you.

If you have hearing problems, help is available. Medical treatment, various forms of amplification systems and simple coping skills can improve your hearing and quality of life.