To say that hearing loss is widespread is somewhat of an understatement. In the United States, 48 million individuals report some level of hearing loss. Which 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 do you prevent becoming one of those five?
To help you understand how to sustain healthier hearing throughout your life, we’ll take a look at the causes and types of hearing loss in this week’s blog.
How Normal Hearing Works
Hearing loss is the interruption of normal hearing, so the best place to start off is with a familiarity of how normal hearing is intended to work.
You can think of normal hearing as consisting of three main processes:
- The physical and mechanical conduction of sound waves. Sound waves are created 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 then transferred to the middle ear bones, which then excite the tiny nerve cells of the cochlea, the snail-shaped organ of the inner ear.
- The electrical conduction from the inner ear to the brain. The cochlea, once stimulated, converts the vibrations into electrical signals that are transmitted to the brain via the auditory nerve.
- The perception of sound within the brain. The brain perceives the electrochemical signal as sound.
What’s interesting is that what we perceive as sound is nothing more than sound waves, oscillations, electricity, and chemical reactions. It’s a fully physical process that leads to the emergence of perception.
The Three Ways Normal Hearing Can Be Interrupted
There are three primary types of hearing loss, each disrupting some element 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 interferes with the physical and mechanical conduction of sound waves to the inner ear and cochlea. This is due to anything that blocks 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 consists of 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 have conductive hearing loss, for example from impacted earwax, you could begin hearing better immediately following a professional cleaning. With the exception of the more serious varieties 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 interferes with the electrical conduction of sound from the cochlea to the brain. This is due to the deterioration to either the nerve cells within the cochlea or to the auditory nerve itself.
With sensorineural hearing loss, the brain is provided with weakened electrical signals, decreasing the volume and quality of sound.
The main 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 exceedingly loud sounds
- Long-term exposure to loud sounds
Sensorineural hearing loss is typically connected with direct exposure to loud sounds, and so can be prevented by staying clear of those sounds or by protecting your hearing with earplugs.
This type of hearing loss is a bit more difficult 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 extremely effective at taking over the amplification assignments of the nerve cells, bringing about the perception of louder, sharper sound.
The third type of hearing loss, mixed hearing loss, is essentially some mixture of conductive and sensorineural hearing loss, and is treated accordingly.
If you have any struggle hearing, or if you have any ear discomfort or lightheadedness, it’s best to talk to your doctor or hearing professional as soon as possible. In nearly every case of hearing loss, you’ll attain the greatest results the earlier you treat the underlying problem.