More than 15 percent of adults over 18 have some type of hearing loss, according to the National Institute on Deafness and Other Communication Disorders.
Normal hearing means hearing sounds that fall between 20 and 20,000 Hz.
A person develops a hearing impairment when a portion of this hearing is lost.
While being hard of hearing and experiencing a profound hearing loss (the type of severe hearing loss that renders you unable to use one or both of your ears for hearing) are different, they have similar underlying causes.
Together, we’ll explore how hearing works, how it is lost, and what types of hearing devices and auxiliary communication tools are available to help a person with hearing impairment live a full and enjoyable life.
How Do We Hear?
The ear has three different parts: the outer ear, middle ear, and inner ear.
- Outer Ear. The outer ear consists of the portion we can see, called the pinna. It also includes the ear canal.
- Middle Ear. The middle ear includes the eardrum and ossicles. The ossicles are three tiny bones located in the middle ear. Individually known as the malleus, incus, and stapes, they are the smallest bones in the entire body.
- Inner Ear. The inner ear includes the spiral-shaped cochlea, the semicircular canals, and the vestibular and auditory nerves. The cochlea contains tiny hairs and the basilar membrane that divides it into two parts. The hair cells sit on top of this membrane.
These structures work together with the brain to transform sound waves into the voices, musical notes, and noises we hear.
The Process of Hearing
The visible part of the ear, the pinna, is designed to collect sound waves in your environment.
These sound waves then travel down the ear canal to the eardrum, where they cause the eardrum to vibrate and move.
The vibrations of the eardrum transfer to the bones in the ear, amplifying the vibrations and causing the fluid inside the cochlea to move.
In response, the tiny hairs also begin to move and interact with neurons that transform the sound waves into electrical signals.
These signals travel through the semicircular canals to the auditory nerve.
The auditory nerve delivers the electrical signals to your brain, which interprets the signals as sound.
All of this happens in literal nanoseconds, but hearing problems occur when a portion of the system is broken or damaged.
What Are the Types of Hearing Loss?
There are several different types of hearing loss and varying degrees of hearing loss.
Someone with permanent hearing loss, for instance, has hearing loss that they will not recover from.
Someone with a partial or unilateral hearing loss may only experience loss of high-frequency sound or only experience a hearing impairment in one ear.
The types of hearing loss differ by the part of the ear that is affected.
Sensorineural Hearing Loss
This hearing loss occurs when structures inside the inner ear become damaged.
Most frequently, the tiny hair cells atop the basilar membrane are damaged or destroyed. We are born with a limited amount of these hairs that do not regenerate. When they are damaged, a portion of our hearing is damaged, too.
Sudden hearing loss, a type of hearing loss that involves the permanent or temporary loss of hearing in one or both ears, is sensorineural hearing loss.
Conductive Hearing Loss
Hearing loss that affects the outer and middle ear structures is called conductive hearing loss.
Often, conductive hearing loss occurs due to injuries, trauma, or genetic abnormalities. Sometimes, surgical repair is needed to correct and restore hearing.
Conductive hearing loss may also be temporary due to a blockage in the ear canal.
Mixed Hearing Loss
As the name suggests, mixed hearing loss involves damage to structures in both the inner and outer or middle ear.
You’ll need an audiologist to help diagnose whether or not you have a hearing loss that involves these different areas of the ear.
Seven Common Causes of Hearing Loss
There are many reasons why someone might lose hearing.
From exposure to loud noise to head or neck trauma, many events impact your ability to hear.
1. Loud Noise
The most common cause of hearing loss is a loud noise, also called noise-induced hearing loss.
Prolonged exposure to loud noises can cause progressive hearing damage over time, and exposure to sudden, impulse noises can also impair your hearing.
Working in a noisy environment like a woodshop, or frequently listening to loud music, can damage the tiny hairs in the inner ear.
Most hearing specialists agree that loud sounds over 70 decibels can cause damage to your cochlea.
2. Presbycusis
Some hearing loss is natural as you get older. Age-related hearing loss, also known as presbycusis, is caused by a breakdown of the structures inside the inner ear.
There’s no cure for presbycusis, but there are treatment options available that can help you continue hearing like you did when you were younger.
Additionally, protecting your hearing while you are young is important to ensure you don’t lose your hearing sooner than you should.
Generally, presbycusis is most common in adults over the age of 65.
3. Otosclerosis
More common in children under 18 who suffer from hearing loss, otosclerosis is an overgrowth of the bones in the middle ear.
The stapes, one of the three bones, begins to grow and fuse with the surrounding bones.
When this happens, the bones become fixed and unable to move.
When they cannot move, they cannot transmit sound waves, making it hard for sound waves to transfer to the cochlea.
Otosclerosis may not cause total deafness. Normally, it causes progressive hearing loss and worsens over time.
4. Diseases and Infections
Although rare in terms of their ability to permanently damage hearing, some diseases and illnesses can cause hearing impairment.
Recurrent, severe ear infections and viruses like mumps and meningitis can have ototoxic effects that cause hearing loss.
Although mumps is rare because of vaccine usage, it is still considered a leading cause of unilateral deafness in children.
Likewise, meningitis may also attack the structures of the inner ear and cause permanent or temporary deafness.
Certain diseases, like Ménière’s Disease, a disorder of the inner ear, can also lead to hearing loss and other symptoms like vertigo and dizziness.
5. Tumors
Tumors or growths that can lead to hearing loss are usually benign and can be surgically removed to restore hearing.
Acoustic neuromas, a type of tumor growing on the vestibular nerve in the inner ear, can cause hearing loss and balance issues.
6. Buildup of Earwax
Earwax helps protect the ear from anything that could enter it and cause harm.
The body produces earwax and moves old earwax out through jaw movement. However, sometimes, earwax isn’t removed properly by the body, leaving a buildup that can make it difficult for you to hear.
Your healthcare provider can remedy this temporary hearing loss — they can use specialized tools to safely and effectively remove the earwax from the ear canal.
7. Medications
Medications with ototoxic effects can cause hearing loss and tinnitus (ringing in the ears).
However, the loss is generally temporary and comes back once the medication is no longer in use. These medications include diuretics, blood pressure medications, and certain over-the-counter pain relievers.
Diagnosing Hearing Loss
If you suspect hearing loss, your healthcare provider can refer you to an audiologist, who will administer a hearing test.
This test can determine the level of hearing loss you are experiencing and also help you understand your type of hearing loss.
If a hearing test, called an audiogram, isn’t able to pinpoint a loss, but you still have trouble hearing, your doctor may use other testing methods.
Some of these include measuring how well you can hear a conversation with background noise or answering a questionnaire about your hearing and communication habits.
Treating Hearing Loss
Once you understand the type and degree of hearing loss you have, you can take action to correct your loss and hear more clearly.
New advances in the types of hearing aids available and surgical techniques mean that almost any type of hearing impairment can be corrected.
Hearing Aids
Digital hearing aids amplify sound through a microphone and deliver the sound waves to the cochlea.
These hearing aids can often automatically adjust sounds so that no manual adjustment is needed.
Hearing aids are normally very small, barely noticeable, and comfortable to wear.
Cochlear Implants
For severe hearing loss, cochlear implants may be an option.
These implants are surgically placed and bypass the damaged part of the inner ear to deliver electrical signals directly to the auditory nerve. The nerve then sends the signal to the brain so the wearer can hear sound.
Sign Language/Lip Reading
This auxiliary communication is a great help for people who experience complete or partial deafness.
Lip reading can make it easier for someone who cannot hear high-frequency consonants (like F, S, and H) to communicate by focusing on the mouth movements that produce these sounds.
Sign language can help two people communicate fully without using any sound.
Prevention
No treatment plan for hearing loss is complete without prevention.
Taking care of your current level of hearing is vital. Making sure your loud noise exposure is limited and wearing earplugs in noisy environments can help you retain your hearing longer.
Healthy Hearing
There are many different ways you can lose your hearing and many different types of hearing loss.
Although it can be life-altering to lose your hearing, there are treatment options available that can help you live a full and happy life and continue communicating well with others.
For more information, check out the USA Rx blog.
You’ll find articles about hearing loss, prevention, and treatment options that might work for you.
References, Studies and Sources:
Quick Statistics About Hearing | NIDCD
Acoustic neuroma – Symptoms and causes | Mayo Clinic
Hypertension, Diuretic Use, and Risk of Hearing Loss | PMC
Deafness following mumps: the possible pathogenesis and incidence of deafness | PubMed