Although it is true that as we grow older our hearing organ deteriorates as do other parts of our body, this does not mean that seniors have to live with it. Understanding the common causes of hearing loss in seniors and what can be done will be useful to all parties concerned.

Hearing loss that is significant enough to interfere with social function affects 25% of persons age 65 to 74 and 50% of those age 75 and older. Not being able to hear or understand conversations as one gets older not only reduces social interaction, it can also lead to isolation and depression.

Do I have hearing loss?

The problem with mild hearing loss is that it is often not noticed by anyone except those nearest and dearest to the person involved. Many seniors are reluctant to admit that they can’t hear very well and this often starts as difficulty to understand speech in the presence of background noises. This can be accompanied by ringing or hissing sounds, also known in medical parlance as tinnitus.

Tinnitus is a sound that is constantly heard without any external stimuli. The combination of tinnitus with hearing loss is common in the elderly person and can lead to gradual social isolation, depression and even paranoia in some.

For instance, a wife who is hard of hearing sees the husband talking to the maid and starts to suspect “foul play”. Younger members of society tend to tire of repeating themselves to the person who is hard of hearing, and gradually shun socialising with them. In addition, the television volume or music is often louder than usual and conversations over the telephone become a session in frustration.

What are the common causes in the elderly?

Common causes of hearing loss, for example, wax build-up, or infection, are seen in all age groups, the young and elderly alike. Certain conditions are more exclusive to the elderly and foremost among these is presbycusis, the normal loss of good hearing that goes with ageing, noise induced hearing loss and ototoxicity.

Presbycusis refers to sensory neural hearing loss that occurs with advancing age. Sensory neural refers to damage of the sensory organ (cochlea) and the neural (nerve) connections between the cochlea and the brain. Although this is the commonest cause of hearing impairment in the elderly, the exact mechanism is still largely unknown. For those of you who seek the opinion of an ENT (Ear Nose and Throat) specialist, you might be told that there are four types of presbycusis. All can be found simultaneously in one person, thus it is not easy to determine which type of presbycusis one is suffering from.

Sensory presbycusis: this refers to the slow death of cells in the cochlea (inner ear), which receive the higher frequency sound waves. This occurs slowly over time. The sufferer often retains the ability to discriminate spoken words.

Neural presbycusis: this refers to the death of nerve cells in both the inner ear and the connecting nerves to the brain. This loss is often a genetic trait. People with this type of presbycusis often have problems following conversations in noisy environments. High frequency hearing loss is common.

Metabolic (strial) presbycusis: The cells that maintain the chemical balance of the cochlea die and this causes a hearing loss that affects all frequencies. However, the ability to discriminate speech is often spared. Thus the social impairment is significantly less that neural presbycusis. This condition is also believed to be familial.

Mechanical presbycusis: In normal hearing, a membrane in the inner ear vibrates with sound and assists in the perception of the pitch. Thickening of this membrane (basilar membrane) causes high frequency hearing loss that worsens with time.

Presbycusis is diagnosed when no abnormalities are found in the ear canal, ear drum or middle ear space. Of course your doctor should rule out simple causes of hearing loss such as wax or infection as this can be treated quite easily before considering presbycusis.

Noise induced hearing loss

Hearing loss caused by exposure to recreational and occupational noise results in disability that is virtually 100% preventable. Noise-induced hearing loss is the second most common form of sensorineural hearing deficit, after presbycusis (age-related hearing loss).

Prolonged continuous exposure to noise is a common cause of hearing impairment. This is common in industrialised countries and is increasing in a developing country like ours. Noise induced hearing loss can be due to prolonged exposure to noisy machinery at work for many years, firing guns and using powered tools. The hair cells in the organ of hearing in the inner ear are sensitive to loud noises. They are damaged after prolonged exposure. Initially this damage is reversible and hearing may revert to normal over time, but prolonged exposure leads to irreversible damage. This is often accompanied by tinnitus.

Ototoxicity

Seniors should be aware that they are more susceptible to drug related complications affecting their hearing. Ototoxicity refers to auditory (hearing loss, tinnitus) and/or vestibular (imbalance, vertigo) complications of medications.

There is a wide range of drugs that can cause ototoxicity. The hearing loss is typically sensorineural and affects both ears. Tinnitus is common. Although some cases of ototoxicity are reversible, this condition can severely limit quality of life, especially if both hearing and balance are affected.

Seniors and their children should be aware of some commonly used medications that may have the potential of causing ototoxicity. Some are antibiotics, although these are not commonly prescribed outside the hospital setting. Diuretics or tablets that make one pass more water such as lasix, certain anti-cancer drugs, and too much aspirin can cause problems with hearing. People who overdose themselves with aspirin will have ringing in their ears. Rest assured that the aspirin tablet that many take to prevent heart attacks and strokes is a very small dose and will not cause any hearing problems.

I may have hearing loss, what should I do?

The best option will be to seek the advice of a medical doctor, who should take a detailed history regarding the hearing loss and other factors such as family history, medications, occupation and exposure to loud noises. If, on examining the ears, the cause is identified (for example, wax or infection), then appropriate treatment will be carried out. If no physical abnormality is detected, a tuning fork examination or a voice test can be performed.

Sometimes the doctor will request an audiogram, which is a test of hearing usually performed in a soundproofed room. This will document the exact frequency and the level of hearing loss involved. Depending on the type and severity of hearing loss, treatment will be provided.

For most sensorineural hearing loss, a hearing aid can be very beneficial. In severe cases, hearing rehabilitation may be required and in specific selected cases, a cochlear implant may be considered.

What can I do to prevent hearing loss?

To reduce your risk of hearing loss, start early. Leading a healthy lifestyle, avoiding ear digging (as you can easily traumatise your ears) and protecting your ears from loud noises are probably the simplest and easiest ways of keeping your hearing sharp.

If you have to be in a noisy environment, do so for as short a time as possible, or wear hearing protection such as ear plugs or similar protective aids.

If you have other medical conditions, for example diabetes or hypertension, ensure that you keep a close check on these conditions as you do not really want to suffer any complications that might lead to hearing loss.

Finally, consult a doctor as soon as possible if you have persistent tinnitus as it could be an early sign of hearing loss or ototoxicity.

By Dr. Prepageran Narayanan and Dr. Philip Poi Jun Hua
http://thestar.com.my/health/story.asp?file=/2006/3/5/health/13565491