To say that hearing loss is common is a bit of an understatement. In the US, 48 million people describe some measure of hearing loss. That means, on average, for every five people you encounter, one will have hearing loss. And at the age of 65, it’s one out of three.
With odds like this, how can you avoid becoming one of those five?
To help you understand how to sustain healthier 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 a good place to start off 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 produced in the environment and propel through the air, like ripples in a lake, ultimately making their way to the external ear, through the ear canal, and ultimately striking the eardrum. The vibrations from the eardrum are subsequently transferred to the middle ear bones, which then trigger 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 delivered to the brain via the auditory nerve.
- 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, oscillations, electricity, and chemical reactions. It’s an entirely physical process that leads to the emergence of perception.
The Three Ways Normal Hearing Can Go Wrong
There are three main types of hearing loss, each disrupting some component of the normal hearing process:
- Conductive hearing loss
- Sensorineural hearing loss
- Mixed hearing loss (a mixture 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 hinders conduction.
Examples include malformations of the outer ear, foreign objects inside of the ear canal, fluid from ear infections, perforated eardrums, impacted earwax, and benign tumors, among other causes.
Treatment of conductive hearing loss includes the removal 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 begin hearing better instantly after a professional cleaning. With the omission of the more serious types of conductive hearing loss, this type can be the fastest to treat and can restore normal hearing entirely.
Sensorineural Hearing Loss
Sensorineural hearing loss inhibits the electrical conduction of sound from the inner ear 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 diminished 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 injuries
- Meniere’s disease
- Cancerous growths of the inner ear
- Side effects of medication
- Abrupt exposure to exceedingly loud sounds
- Long-term subjection to loud sounds
Sensorineural hearing loss is in most cases associated with direct exposure to loud sounds, and so can be prevented by staying clear of those sounds or by shielding your hearing with earplugs.
This type of hearing loss is a little more challenging to treat. There are no current 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 responsibilities of the nerve cells, leading to the perception of louder, clearer sound.
The third type of hearing loss, mixed hearing loss, is essentially some combination of conductive and sensorineural hearing loss, and is treated accordingly.
If you have any difficulties hearing, or if you have any ear discomfort or dizziness, it’s best to contact your doctor or hearing professional as soon as possible. In nearly every instance of hearing loss, you’ll get the greatest results the sooner you attend to the underlying problem.