The Types and Causes of Hearing Loss

To express that hearing loss is common is a bit of an understatement. In the United States, 48 million people report some level of hearing loss. Which means, on average, for every five people you meet, one will have hearing loss. And at the age of 65, it’s one out of three.

With odds like this, how do you escape becoming one of those five?

To help you understand how to preserve healthy hearing throughout your life, we’ll take a closer look at the causes and types of hearing loss in this week’s posting.

How Healthy Hearing Works

Hearing loss is the interruption of normal hearing, so an appropriate place to start is with a familiarity of how normal hearing is intended to work.

You can picture normal hearing as composed of three primary processes:

1. The physical and mechanical conduction of sound waves. Sound waves are produced in the environment and propel through the air, like ripples in a pond, eventually making their way to the external ear, through the ear canal, and finally hitting the eardrum. The vibrations from the eardrum are then transferred to the middle ear bones, which then activate the tiny nerve cells of the cochlea, the snail-shaped organ of the inner ear.
2. The electrical conduction from the inner ear to the brain. The cochlea, once stimulated, translates the vibrations into electrical signals that are delivered via the auditory nerve to the brain.
3. The perception of sound within the brain. The brain perceives the electrochemical signal as sound.

What’s fascinating is that what we perceive as sound is nothing more than sound waves, vibrations, electricity, and chemical reactions. It’s a wholly physical process that leads to the emergence of perception.

The Three Ways Normal Hearing Can Be Disrupted

There are three main types of hearing loss, each interfering with some aspect of the normal hearing process:

1. Conductive hearing loss
2. Sensorineural hearing loss
3. Mixed hearing loss (a mix of conductive and sensorineural)

Let’s take a look at the first two, including the causes and treatment of each.

Conductive Hearing Loss

Conductive hearing loss interferes with the physical and mechanical conduction of sound waves to the inner ear and cochlea. This is a consequence of anything that obstructs conduction.

Examples include malformations of the outer ear, foreign objects inside of the ear canal, fluid from ear infections, pierced eardrums, impacted earwax, and benign tumors, among other causes.

Treatment of conductive hearing loss includes extracting the obstruction, treating the infection, or surgical correction of the malformation of the outer ear, the eardrum, or the middle ear bones.

If you suffer from conductive hearing loss, for example from impacted earwax, you could possibly start hearing better instantly following a professional cleaning. With the exception of the more serious forms of conductive hearing loss, this type can be the simplest to treat and can bring back normal hearing completely.

Sensorineural Hearing Loss

Sensorineural hearing loss inhibits the electrical conduction of sound from the cochlea to the brain. This is caused by injury to either the nerve cells within the cochlea or to the auditory nerve itself.

With sensorineural hearing loss, the brain is provided with compromised electrical signals, limiting the volume and clarity of sound.

The principal causes of sensorineural hearing loss are:

• Genetic syndromes or fetal infections
• Typical aging (presbycusis)
• Infections and traumatic injuries
• Meniere’s disease
• Cancerous growths of the inner ear
• Side effects of medication
• Sudden exposure to very loud sounds
• Long-term exposure to loud sounds

Sensorineural hearing loss is most often associated with direct exposure to loud sounds, and so can be protected against by staying away from those sounds or by shielding your hearing with earplugs.

This form of hearing loss is a little more complicated to treat. There are no current surgical or medical procedures to repair the nerve cells of the inner ear. However, hearing aids and cochlear implants are very effective at taking on the amplification functions of the nerve cells, producing the perception of louder, clearer sound.

The third type of hearing loss, mixed hearing loss, is simply some mixture of conductive and sensorineural hearing loss, and is treated accordingly.

If you have any struggle hearing, or if you have any ear pain or dizziness, it’s best to talk with your doctor or hearing professional as soon as possible. In virtually every instance of hearing loss, you’ll attain the best results the earlier you address the underlying issue.