Hearing loss

Overview

Hearing loss that occurs gradually as you age (presbycusis) is common. About one-third of people in the United States between the ages of 65 and 75 have some degree of hearing loss. For those older than 75, that number is approximately 1 in 2.

Hearing loss is defined as one of three types:

  • Conductive (involves outer or middle ear)
  • Sensorineural (involves inner ear)
  • Mixed (combination of the two)

Aging and chronic exposure to loud noises both contribute to hearing loss. Other factors, such as excessive earwax, can temporarily reduce how well your ears conduct sounds.

You can't reverse most types of hearing loss. However, you and your doctor or a hearing specialist can take steps to improve what you hear.

Symptoms

Signs and symptoms of hearing loss may include:

  • Muffling of speech and other sounds
  • Difficulty understanding words, especially against background noise or in a crowd
  • Trouble hearing consonants
  • Frequently 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

When to see a doctor

If you have a sudden loss of hearing, particularly in one ear, seek immediate medical attention.

Talk to your doctor if difficulty hearing is interfering with your daily life. Age-related hearing loss occurs gradually, so you may not notice it at first.

Causes

To understand how hearing loss occurs, it can be helpful to first understand how you hear.

How you hear

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 amplify the vibrations as they travel to the inner ear. There, the vibrations pass through fluid in a snail-shaped structure in the inner ear (cochlea).

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. Your brain turns these signals into sound.

How hearing loss can occur

Causes of hearing loss include:

  • Damage to the inner ear. Aging and exposure to loud noise may cause wear and tear on the hairs or nerve cells in the cochlea that send sound signals to the brain. When these hairs or nerve cells 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.

  • Gradual buildup of earwax. Earwax can block the ear canal and prevent conduction of sound waves. Earwax removal can help restore your hearing.
  • Ear infection and abnormal bone growths or tumors. In the outer or middle ear, any of these can cause hearing loss.
  • Ruptured eardrum (tympanic membrane perforation). Loud blasts of noise, sudden changes in pressure, poking your eardrum with an object and infection can cause your eardrum to rupture and affect your hearing.
Inside of your ear

The middle ear includes three small bones — the hammer (malleus), anvil (incus) and stirrup (stapes). The middle ear is separated from your external ear by the eardrum and connected to the back of your nose and throat by a narrow passageway called the eustachian tube. The cochlea, a snail-shaped structure, is part of your inner ear.

Inside of your ear

The middle ear includes three small bones — the hammer (malleus), anvil (incus) and stirrup (stapes). The middle ear is separated from your external ear by the eardrum and connected to the back of your nose and throat by a narrow passageway called the eustachian tube. The cochlea, a snail-shaped structure, is part of your inner ear.

Risk factors

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

  • Aging. Degeneration of inner ear structures occurs over time.
  • Loud noise. Exposure to loud sounds can damage the cells of your inner ear. Damage can occur with long-term exposure to loud noises, or from a short blast of noise, such as from a gunshot.
  • Heredity. Your genetic makeup may make you more susceptible to ear damage from sound or deterioration from aging.
  • Occupational noises. Jobs where loud noise is a regular part of the working environment, such as farming, construction or factory work, can lead to damage inside your ear.
  • Recreational noises. Exposure to explosive noises, such as from firearms and jet engines, can cause immediate, permanent hearing loss. Other recreational activities with dangerously high noise levels include snowmobiling, motorcycling, carpentry or listening to loud music.
  • Some medications. Drugs such as the antibiotic gentamicin, sildenafil (Viagra) and certain chemotherapy drugs, can damage the inner ear. Temporary effects on your hearing — ringing in the ear (tinnitus) or hearing loss — can occur if you take very high doses of aspirin, other pain relievers, antimalarial drugs or loop diuretics.
  • Some illnesses. Diseases or illnesses that result in high fever, such as meningitis, may damage the cochlea.

Comparing loudness of common sounds

The chart below lists common sounds and their decibel levels. The Environmental Protection Agency's (EPA) safe noise level is 70 decibels. The louder the noise, the less time it takes to cause permanent hearing damage.

Sound levels of common noises
Decibels Noise source
Safe range
30 Whisper
40 Refrigerator
60 Normal conversation
75 Dishwasher
Risk range
85 Heavy city traffic, school cafeteria
95 Motorcycle
100 Snowmobile
110 Chain saw, jackhammer, rock concert, symphony
115 Sandblasting
120 Ambulance siren, thunder
140-165 Firecracker, firearms

Maximum sound-exposure durations

Below are the maximum noise levels on the job to which you may be exposed without hearing protection, and for how long.

Maximum job-noise exposure allowed by law
Sound level, decibels Duration, daily
BASED ON OCCUPATIONAL SAFETY & HEALTH ADMINISTRATION, 2008
90 8 hours
92 6 hours
95 4 hours
97 3 hours
100 2 hours
102 1.5 hours
105 1 hour
110 30 minutes
115 15 minutes or less

Complications

Hearing loss can have a significant effect on your quality of life. Older adults with hearing loss may report feelings of depression. Because hearing loss can make conversation difficult, some people experience feelings of isolation. Hearing loss is also associated with cognitive impairment and decline.

The mechanism of interaction between hearing loss, cognitive impairment, depression and isolation is being actively studied. Initial research suggests that treating hearing loss can have a positive effect on cognitive performance, especially memory.

Prevention

The following steps can help you prevent noise-induced hearing loss and avoid worsening of age-related hearing loss:

  • Protect your ears. Limiting the duration and intensity of your exposure to noise is the best protection. In the workplace, plastic earplugs or glycerin-filled earmuffs can help protect your ears from damaging noise.
  • Have your hearing tested. Consider regular hearing tests if you work in a noisy environment. If you've lost some hearing, you can take steps to prevent further loss.
  • Avoid recreational risks. Activities such as riding a snowmobile, hunting, using power tools or listening to rock concerts can damage your hearing over time. Wearing hearing protectors or taking breaks from the noise can protect your ears. Turning down the music volume is helpful too.

Diagnosis

Tests to diagnose hearing loss may include:

  • Physical exam. Your doctor will look in your ear for possible causes of your hearing loss, such as earwax or inflammation from an infection. Your doctor will also look for any structural causes of your hearing problems.
  • General screening tests. Your doctor may use the whisper test, asking 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. Its accuracy can be limited.
  • App-based hearing tests. Mobile apps are available that you can use by yourself on your tablet to screen for moderate hearing loss.
  • Tuning fork tests. Tuning forks are two-pronged, metal instruments that produce sounds when struck. Simple tests with tuning forks can help your doctor detect hearing loss. This evaluation may also reveal where in your ear the damage has occurred.
  • Audiometer tests. During these more-thorough tests conducted by an audiologist, you wear earphones and hear sounds and words directed to each ear. Each tone is repeated at faint levels to find the quietest sound you can hear.

Treatment

If you have hearing problems, help is available. Treatment depends on the cause and severity of your hearing loss.

Options include:

  • Removing wax blockage. Earwax blockage is a reversible cause of hearing loss. Your doctor may remove earwax using suction or a small tool with a loop on the end.
  • Surgical procedures. Some types of hearing loss can be treated with surgery, including abnormalities of the ear drum or bones of hearing (ossicles). If you've had repeated infections with persistent fluid, your doctor may insert small tubes that help your ears drain.
  • Hearing aids. If your hearing loss is due to damage to your inner ear, a hearing aid can be helpful. An audiologist can discuss with you the potential benefits of a hearing aid and fit you with a device. Open fit aids are currently the most popular, due to fit and features offered.
  • Cochlear implants. If you have more severe hearing loss and gain limited benefit from conventional hearing aids, then a cochlear implant may be an option. Unlike a hearing aid that amplifies sound and directs it into your ear canal, a cochlear implant bypasses damaged or nonworking parts of your inner ear and directly stimulates the hearing nerve. An audiologist, along with a medical doctor who specializes in disorders of the ears, nose and throat (ENT), can discuss the risks and benefits.
Hearing aid with common parts labeled

Hearing aids use these parts to help channel and amplify sound from your environment into your ear — microphone (detects sound), amplifier (makes sound stronger), speaker (sends sound into your ear), battery (provides power). Some also have a volume control or a program button.

Common hearing aid styles

Many choices of hearing aid styles are available, including: completely in the canal (A), in the canal (B), in the ear (C), behind the ear (D), receiver in the canal or receiver in the ear (E), and open fit (F).

How cochlear implants work

Cochlear implants use an external microphone and speech processor that you generally wear behind your ear. Different styles are available. A transmitter sends radiofrequency signals to a surgically implanted receiver and stimulator unit. The unit stimulates the auditory nerve with electrodes that have been threaded into the cochlea.

Coping and support

These tips can help you communicate more easily despite your hearing loss:

  • Tell your friends and family. Let them know that you have some hearing loss.
  • Position yourself to hear. Face the person you're talking to.
  • Turn off background noise. For example, noise from a television may interfere with conversation.
  • Ask others to speak clearly, but not more loudly. Most people will be helpful if they know you're having trouble hearing them.
  • Try to have the other person's attention before speaking. Avoid trying to converse with someone in a different room.
  • Choose quiet settings. In public, choose a place to talk that's away from noisy areas.
  • Consider using an assistive listening device. Hearing devices, such as TV-listening systems or phone-amplifying devices, smartphone or tablet apps, and closed-circuit systems in public places can help you hear better while decreasing other noises around you.

Preparing for an appointment

If you suspect you may have hearing loss, call your doctor. After an initial evaluation, your doctor may refer you to a hearing specialist (audiologist).

Here's some information to help you prepare for your appointment.

What you can do

  • Write down your symptoms and how long you've had them. Is the hearing loss in one ear or both? Ask friends and family to help you make the list. They may have noticed changes that aren't obvious to you, but the changes may be important for your doctor to know.
  • Write down key medical information, especially related to any ear problems. Include any chronic infections, injury to your ear or previous ear surgery. Also list medications, vitamins or supplements you take.
  • Summarize your work history, including any jobs, even those in the distant past, that exposed you to high noise levels.
  • Take a family member or friend along. Someone who accompanies you can help you remember all the information from your doctor.
  • Write down questions for your doctor.

For hearing loss, some questions to ask include:

  • What's the most likely cause of my symptoms?
  • What else might be causing my symptoms?
  • What tests do you recommend?
  • Should I stop taking any of my current medications?
  • Should I see a specialist?

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

  • How would you describe your symptoms? Do you have pain or drainage in the affected ear or ears?
  • Did your symptoms come on suddenly?
  • Do you have ringing, roaring or hissing in your ears?
  • Do your symptoms include dizziness or balance problems?
  • Do you have a history of ear infections, ear trauma or ear surgery?
  • Have you ever worked in a job that exposed you to loud noise, flown airplanes or been in military combat?
  • Does your family complain that you turn up the volume of the television or radio too high?
  • Do you have trouble understanding someone talking to you in a low voice?
  • Do you have trouble understanding someone on the telephone?
  • Do you often need to ask others to speak up or repeat themselves? Does this happen more often in a noisy setting, such as a crowded restaurant?
  • Can you hear a coin hitting the floor or a door closing?
  • Can you hear when someone approaches you from behind?
  • If your hearing is impaired, does it bother you or affect your quality of life?
  • Would you be willing to try a hearing aid?

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