Don’t turn a deaf ear to hearing loss

Gradual loss of hearing that occurs with age is common.  An estimated one-quarter of the population between the ages of 65 and 75 have some degree of hearing loss, and among those 75 and older, three of four have difficulty hearing.

As baby boomers reach retirement age, the number of people with hearing loss is expected to increase significantly.  This is the first generation to grow up with rock concerts, high-tech music amplifiers, jet engine noise, and power lawn mowers.

If you’ve already experienced some inner ear hearing loss, you usually can’t get back what’s gone.  But with the help of an ENT doctor or a hearing specialist (audiologist), you may be able to hear some sounds you’re currently missing.  Proper treatment can make communication, social interaction, and work and daily activities easier and more enjoyable.

How you hear

Hearing begins when sound waves are collected by your outer ear and then channeled along the ear canal to the ear drum (see diagram). The impact of sound hitting the eardrum creates vibrations that cause three bones in the middle ear — the hammer, anvil, and stirrup — to move.  This amplifies the vibrations as they travel to the inner ear.

In the inner ear, the vibrations pass through fluid located within a snail-shaped structure called the cochlea.  This produces a wave-like action affecting thousands of sensory cells called hair cells.  Tiny hairs project from the tips of the cells. The wave-like action bends the hairs, setting off patterns of electrical pulses that are transmitted along the auditory nerve that runs from the inner ear to your brain.  Your brain interprets the impulses as sound.

Because different sounds produce different vibrations that affect the tiny hairs in different ways, the patterns transmitted to your brain vary.  That’s how you distinguish one sound from another.

Types of hearing loss

Hearing loss results when something goes wrong along the sound pathway from your outer ear to your brain.  There are three main types of hearing loss, categorized by where on the pathway signals becomes blocked or interrupted:

• Conductive hearing loss.  This occurs when the outer or middle ear fails to work properly.  Sounds become “blocked” and aren’t carried to the inner ear.  Conductive hearing loss is often treatable — the problem can be fixed with medicine, surgery, or something as simple as cleaning out your ear canal.  Common causes are fluid behind the eardrum or wax buildup in the ear canal.  This type of hearing loss can also occur when the eardrum or bones of the middle ear don’t function normally, due to an injury or other medical conditions.

•  Sensorineural hearing loss.  This results when the inner ear is damaged.  The most common causes are wear and tear on inner ear structures due to aging and noise exposure.  Sensorineural hearing loss usually isn’t treatable with medication or surgery.  Sometimes, hearing loss occurs when the auditory nerve or the nervous system is damaged.  One cause of this type of hearing loss is a non-cancerous (benign) tumor, such as an acoustic neuroma, that presses on the auditory nerve.  Surgery is usually necessary to remove the tumor. 

• Mixed hearing loss.  This is the description of a condition in which you have a combination of conductive and sensorineural hearing loss.

What puts you at risk

Most hearing loss results from damage to the cochlea, the snail-shaped structure in the inner ear.  Tiny hairs in the cochlea may break or become damaged, and hair cells may deteriorate.  When the cells or the hairs are damaged or missing, electrical signals aren’t transmitted as efficiently and hearing loss occurs.

Factors that may damage or lead to loss of hair cells in your inner ear include:

• Aging.  Normal wear and tear over the years from sound can damage the cells of your inner ear.  Age-related hearing loss (presbycusis) is the most common cause of hearing loss.

• Loud noise. Occupational noise, such as from construction, factory work, and recreational activities (e.g., listening to loud music), can contribute to damage inside your inner ear.

• Heredity. Your genetic makeup may make you more susceptible to ear damage.

•  Medications.  Drugs such as the antibiotic gentamicin and certain chemotherapy drugs can damage your inner ear.  Usually, temporary effects on your hearing — ringing in the ear or hearing loss — can occur if you take very high doses of aspirin, certain types of diuretics such as furosemide (Lasix), or some drugs used to treat malaria.

• Some illnesses. Certain diseases or illnesses that result in an infection, such as meningitis, can damage the cochlea.

Treating hearing loss

Treatment for hearing loss depends on the cause and severity of the loss. If your hearing loss is the result of earwax blockage, your doctor or audiologist can remove the wax.  If an ear infection is at fault, medications are often prescribed.  If the eardrum is perforated, it may heal itself or may be “patched” surgically.  For excess bone growth or tumors in the middle ear, surgery is usually necessary.

The most common remedy for sensorineural hearing loss is a hearing aid or another assistive listening device.  A hearing aid can make sounds stronger and easier for you to interpret and understand.

Many people with hearing loss are hesitant to wear a hearing aid because they worry about how it will look and whether it will really help. But wearing a hearing aid is much less noticeable than constantly asking people to repeat themselves or responding to a question with an unrelated answer.  In addition, the devices have become so automated in recent years that they require little, if any, adjustments.  Furthermore, hearing aids don’t look much different from portable music devices.

Knowing more about the types of hearing aids available, what to look for when buying them, and how to get accustomed to them can help alleviate some of your concerns. An audiologist can assist you with this information.  Hearing aids can’t help everyone with hearing loss, but they can improve hearing for many people.