The Types and Causes of Hearing Loss
To say that hearing loss is widespread is a bit of an understatement. In the US, 48 million people describe some level of hearing loss. Meaning, 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 conserve healthier hearing all through your life, we’ll take a look at the causes and types of hearing loss in this week’s blog post.
How Healthy Hearing Works
Hearing loss is the interruption of normal hearing, so the best place to get started is with a familiarity of how normal hearing is supposed to work.
You can picture normal hearing as comprised of three primary processes:
- The physical and mechanical conduction of sound waves. Sound waves are created in the environment and move through the air, like ripples in a pond, ultimately making their way to the external ear, through the ear canal, and finally striking the eardrum. The vibrations from the eardrum are subsequently transferred to the middle ear bones, which then stimulate the tiny nerve cells of the cochlea, the snail-shaped organ of the inner ear.
- The electrical transmission from the inner ear to the brain. The cochlea, once stimulated, converts the vibrations into electrical impulses that are transmitted via the auditory nerve to the brain.
- The perception of sound in 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, oscillations, electric current, 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 primary types of hearing loss, each interfering with some aspect of the normal hearing process:
- Conductive hearing loss
- Sensorineural hearing loss
- Mixed hearing loss (a mix of conductive and sensorineural)
Let’s take a closer look at the first two, including the causes and treatment of each.
Conductive Hearing Loss
Conductive hearing loss impedes the physical and mechanical conduction of sound waves to the inner ear and cochlea. This is due to 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 getting rid of the obstruction, treating the infection, or surgical correction of the malformation of the outer ear, the eardrum, or the middle ear bones.
If you have conductive hearing loss, for instance from impacted earwax, you could possibly start hearing better instantly after a professional cleaning. With the exception of the more serious forms of conductive hearing loss, this type can be the fastest to treat and can restore normal hearing entirely.
Sensorineural Hearing Loss
Sensorineural hearing loss impedes the electrical conduction of sound from the cochlea to the brain. This is due to the damage 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, reducing the volume and clarity of sound.
The principal causes of sensorineural hearing loss are:
- Genetic syndromes or fetal infections
- Normal aging (presbycusis)
- Infections and traumatic accidents
- Meniere’s disease
- Cancerous growths of the inner ear
- Side effects of medication
- Abrupt exposure to extremely loud sounds
- Long-term exposure to loud sounds
Sensorineural hearing loss is in most cases associated with exposure to loud sounds, and so can be prevented by circumventing those sounds or by shielding your hearing with earplugs.
This form of hearing loss is a little more complicated to treat. There are no present surgical or medical procedures to heal the nerve cells of the inner ear. However, hearing aids and cochlear implants are very effective at taking on the amplification duties of the nerve cells, resulting in the perception of louder, clearer sound.
The third type of hearing loss, mixed hearing loss, is basically some combination of conductive and sensorineural hearing loss, and is treated accordingly.
If you have any difficulty hearing, or if you have any ear pain or lightheadedness, it’s a good idea to pay a visit to your physician or hearing professional right away. In almost every case of hearing loss, you’ll get the best results the earlier you treat the underlying problem.