In association with: MayoClinic.com
advertisement

INFORMATION CENTERS:
Note: All links within content go to MayoClinic.com external link
Diseases and Conditions
Hearing loss
From MayoClinic.com
Special to CNN.com

Introduction

The gradual hearing loss that occurs as you age (presbycusis) is a common condition. An estimated one-third of Americans older than age 60 and one-half of those older than age 85 have some degree of hearing loss.

Over time, the wear and tear on your ears from noise contributes to hearing loss by damaging the cochlea, a part of 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 (audiologist) can take steps to improve what you hear.

Signs and symptoms

Signs and symptoms of hearing loss may include:

  • Muffled quality of speech and other sounds
  • Difficulty understanding words, especially against background noise or in a crowd of people
  • Asking others to speak more slowly, clearly and loudly
  • Needing to turn up the volume of the television or radio
  • Withdrawal from conversations
  • Avoidance of some social settings

Causes

Hearing occurs when sound waves reach the structures inside your ear, and your ear converts the sound wave vibrations into nerve signals that your brain recognizes as sound.

Your ear consists of three major areas: 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, the anvil and the 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.

For some people, hearing loss may result from a gradual buildup of earwax, which blocks the ear canal and prevents conduction of sound waves. Earwax blockage is one of the more common causes 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.

Risk factors

Factors that may damage or lead to loss of the hairs and nerve cells in your inner ear include:

  • Aging. The normal wear and tear from sounds over the years can damage the cells of your inner ear.
  • Loud noises. Occupational noise, such as from construction or factory work, and recreational noise, such as from loud music, the engine of a snowmobile or motorcycle, or shooting firearms, can contribute to the damage inside your ear.
  • Heredity. Your genetic makeup may make you more susceptible to ear damage.
  • Some medications. Drugs such as the antibiotic gentamicin can damage the inner ear. For example, temporary effects on your hearing — ringing in the ear (tinnitus) or hearing loss — can occur if you take very high doses of aspirin.
  • Some illnesses. Diseases or illnesses that result in high fever, such as meningitis, may damage the cochlea.

When to seek medical advice

Talk to your doctor if you have difficulty hearing. Your hearing may have deteriorated if you find that it's harder for you 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.

Screening and diagnosis

To determine your ability to hear and the extent of your hearing loss, your doctor or an audiologist may administer hearing tests.

At first, your doctor may conduct 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.

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.

Treatment

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 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 the outer ear or within the 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. Your doctor and audiologist may be able to help you hear better.

Prevention

These steps can help you prevent noise-induced hearing loss:

  • Protect your ears in the workplace. Specially designed earmuffs that resemble earphones can protect your ears by bringing most loud sounds down to an acceptable level. Over-the-counter or custom-molded earplugs made of plastic or rubber also can effectively protect your ears from damaging noise.
  • Have your hearing tested. Consider regular hearing tests if you work in a noisy environment. Regular testing of your ears can provide early detection of hearing loss. Knowing you've lost some hearing means you're in a position to take steps to prevent further hearing loss.
  • Avoid recreational risks. Activities such as riding a snowmobile, trapshooting and listening to extremely loud music can damage your ears. Wearing earplugs during noisy recreational activities can protect your ears. Turning down the volume when listening to music can help you avoid damage to your hearing.

Coping skills

Try these tips to communicate more easily despite your hearing loss:

  • Position yourself to hear. Face the person with whom you're having a conversation.
  • Turn off background noise. For example, noise from a television may interfere with conversation.
  • Ask others to speak clearly. Most people will be helpful if they know you're having trouble hearing them.
  • Choose quiet settings. In public, such as in a restaurant or at a social gathering, choose a place to talk that's away from noisy areas.
  • Consider using a hearing aid. Other hearing devices, such as TV-listening systems or telephone-amplifying devices, can help you hear better while decreasing other noises around you.

August 23, 2005

© 1998-2008 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.  Terms of Use.
Home  |  World  |  U.S.  |  Politics  |  Crime  |  Entertainment  |  Health  |  Tech  |  Travel  |  Living  |  Business  |  Sports  |  Time.com
© 2008 Cable News Network. Turner Broadcasting System, Inc. All Rights Reserved.