Hearing loss has a lot of different causes and manifestations. It can be sudden or gradual. It can occur in one ear or both ears. It can be temporary or permanent. It happens to people of all ages and is associated with the aging process. Before discussing causes and treatments for hearing loss, it is important to understand how hearing works.
How We Hear
There are three sections of the ear: the outer ear, middle ear and inner ear. Each section helps move sound through the process of hearing. When a sound occurs, the outer ear feeds it through the ear canal to the eardrum. The noise causes the eardrum to vibrate. This, in turn, causes three little bones inside the middle ear (malleus, incus, stapes) to move. That movement travels into the inner ear (cochlea), where it makes tiny little hairs move in a fluid. These hairs convert the movement to auditory signals, which are then transmitted to the brain to register the sound.
Causes of Hearing Loss
- In the Outer Ear: Earwax build-up, infections that cause swelling, a growth in the ear canal, injury or birth defects can restrict hearing in the outer ear.
- In the Middle Ear: Fluid build-up is responsible for the most common infections and blockages in the middle ear. Fluid in the middle ear prevents the bones from processing sounds properly. Tumors, both benign and malignant, can also result in hearing loss in the middle ear.
- In the Inner Ear: The natural process of aging diminishes hearing from damage to the cochlea (mechanism for converting sound vibrations to brain signals), vestibular labyrinth (which regulates balance), or the acoustic nerve (nerve that sends sound signals to the brain). Additionally, inner ear infections, Meniere’s disease and other nerve-related problems contribute to hearing loss in the inner ear.
Other causes of hearing loss include:
- Presbycusis: Age-related hearing loss, such as having difficulty hearing in noisy places, having trouble understanding what people are saying or not registering softer sounds.
- Heredity and Genetic Causes: There is a wide variety of diseases and syndromes that are either genetic or hereditary that can cause hearing loss. Some, like rubella (German measles) occur when a pregnant mother has the disease, which causes hearing loss in the baby. Other, rarer types of hereditary and genetic causes include CHARGE Syndrome, Connexin 26 disorder, Goldenhar Syndrome,Treacher Collins Syndrome, Usher Syndrome, Waardenburg Syndrome and otosclerosis (growth of spongy bone tissue in the middle ear).
Types of Hearing Loss
There are five types of hearing loss:
- Conductive hearing loss: Caused by conditions that block the transmission of sound through the outer ear and eardrum to the middle ear.
- Sensorineural hearing loss: Inner ear damage that occurs as part of the natural process of aging.
- Mixed hearing loss: Mixed hearing loss refers to people who have both conductive and sensorineural hearing loss. Most people experience more than one type of hearing loss.
- Central hearing loss: This occurs when the central nervous system fails to send a readable signal to the brain, which is called a central auditory processing disorder. People with central hearing loss generally can hear all sounds, but can’t separate or process them.
Hearing loss is measured in four degrees: mild, moderate, severe or profound. The degree of hearing loss drives the selection of the best form of treatment on a case-by-case basis.
Hearing Loss Treatment
- Antibiotics, decongestants and pain medication to overcome ear infections.
- Myringotomy, a piercing of the eardrum to allow for fluids to drain out of the outer ear.
- Insertion of a tube into the Eustachian tube (part of the anatomy that connects the middle ear to the back of the throat) to keep it open and allow for normal fluid drainage. This technique may be recommended for people who get frequent ear infections.
- Hearing aids.
- Surgery to remove benign or malignant tumors or correct bone- or nerve-related problems.
Hearing Loss and Memory Loss
According to the JAMA Otolaryngology medical journal, there’s a correlation between hearing loss and memory loss, and a recent study has shown significant benefits from using hearing aids. In a risk-adjusted population of people with moderate to severe hearing loss, those who wore hearing aids had 78% less memory loss than those who did not. Those with mild hearing loss who wore hearing aids had 88% less memory loss than those who did not!
To learn more about hearing aids and how we can help you get started, visit our Hearing Aids page.