How you lose your hearing

Hearing loss that occurs gradually as you age (presbycusis) is common.

About 25% of people between the ages of 55 and 64 have some degree of hearing loss. For those older than 65, the number of people with some hearing loss is almost one in every two.

Ageing and chronic exposure to loud noises are significant factors that contribute to hearing loss. Other factors, such as excessive earwax, can temporarily prevent your hearing from conducting sounds as well as they should.

Talk to your doctor immediately if you have a sudden loss of hearing, particularly in one ear or if your hearing difficulty starts interfering with your daily life. If you find that it’s harder to understand what’s being said, especially when there’s background noise, or you find yourself turning up the volume, inquire.

Signs and symptoms

• Muffling of speech and other sounds
• Difficulty understanding words, especially against background noise or in a crowd of people
• 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

Causes

• Damage to the inner ear. Ageing 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. Heredity may make you more prone to these changes. This type of hearing loss is known as sensorineural hearing loss, which is permanent.
• Earwax can block the ear canal and prevent conduction of sound waves. This can be restored with earwax removal. ɳ Ear infection and abnormal bone growths or tumours in the outer or middle ear can cause hearing loss.
• A ruptured eardrum (tympanic membrane perforation) by loud blasts of noise, sudden changes in pressure, poking your eardrum with an object, and infection can affect your hearing.

Risk Factors

• Ageing – Degeneration of delicate 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 ageing.
• Occupational noises – Jobs where loud noise is a regular part of the working environment, such as mining, 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 or loud music.
• Some medications – Drugs, such as the antibiotic gentamicin 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 you running high fever, such as meningitis, may damage the cochlea in the human ear.

Prevention

Here are some of steps you can take to help you prevent noise-induced hearing loss and to avoid worsening of age-related hearing loss.

• Protect your ears in the workplace – Personal protective equipment for hearing can protect your ears by bringing most loud sounds down to an acceptable level. Foam, and pre-formed or custom-moulded earplugs made of plastic or rubber can help protect your ears from damaging noise.
• Regular Audiometry – Consider regular hearing tests if you work in a noisy environment. Regular testing of your hearing 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 – Some activities, such as riding a snowmobile, hunting or listening to rock concerts for long periods of time, can damage your hearing. Wearing hearing protectors or taking breaks from the noise during loud recreational activities can protect your ears. Turning down the volume when listening to music can help you avoid damage.

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 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.
• 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. A tuning fork evaluation may also reveal whether hearing loss is caused by damage to the vibrating parts of your middle ear (including your eardrum), damage to sensors or nerves of your inner ear, or damage to both.
• Audiometer tests – During these, 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 fainter levels to find out when you can barely 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 by loosening it with oil and then flushing, scooping or suctioning out the softened wax.
• Surgical procedures – Surgery may be necessary if you’ve had a traumatic ear injury or repeated infections that require the insertion of small tubes that help the ears drain.
• Hearing aids – If your hearing loss is due to damage to your inner ear, a hearing aid can help by making sounds stronger and easier for you to hear. An audiologist can discuss with you the potential benefits of using a hearing aid, recommend a device and fit you with it.
• Cochlear implants – If you have severe hearing loss, a cochlear implant may be an option for you to consider. 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.