Losing the ability to hear sounds and understand speech is not just an inconvenience. It can lead to social isolation, depression, cognitive decline and can even increase the risk of falling.
“Hearing loss has far-reaching implications,” says Oliver Adunka, MD, director of otology, neurotology, and cranial base surgery at Ohio State University Wexner Medical Center and professor in the department of oto- rhino-laryngology from the Ohio State University College of Medicine. “The consequences are worse than people think. It’s an isolation issue, so depression goes hand in hand with that.
Below we explain the main types of hearing loss.
Conductive hearing loss
Conductive hearing loss involves the outer and middle ear, which is the part of the ear we can see and what lies just beyond it inside the skull. The middle ear contains the eardrum (tympanic membrane) and three small bones that amplify the vibration of the eardrum caused by sound waves.
Conductive hearing loss can be caused by:
- Accumulation of earwax. If there is too much earwax in the ear canal, sound waves cannot enter the middle ear. If the buildup is mild, you can try a home remedy. (But avoid the more dangerous ones, like probing with a cotton swab or other instrument that can push earwax further in or even rupture the eardrum.) Instead, put a few drops of baby oil or mineral oil in the problem ear and let it soak then gently rinse it with lukewarm water the next day or two. If after a few tries the wax does not dislodge, see a healthcare professional who can clean the outer ear canal and make sure that is the only problem. It is one of the simplest ear problems.
- Ear infection. Chronic ear infections can lead to permanent hearing loss by damaging the eardrum or other parts of the middle ear and must be treated promptly. It can happen in one or both ears.
- Otosclerosis. Genetic and environmental factors (such as viral infections) can cause the three tiny bones in the middle ear to become deformed so that they no longer transmit sound to the inner ear. This condition can be repaired with surgery.
- Ruptured eardrum(s). A perforation of the tympanic membrane can be due to a middle ear infection (acute otitis media) or a traumatic injury (such as a very loud explosion) or direct contact (such as poking the ear with a cotton swab , a common cause). Or it can happen spontaneously. The eardrum can usually heal on its own, but surgery may be required. It can be unilateral with only one ear affected or both ears.
Sensorineural hearing loss
Even if the middle ear is healthy and amplifies and transmits sound waves properly, problems can arise in the inner ear where snail-shell cochleas translate these sound waves into electrical signals that travel through the auditory nerves to the brain. This is called sensorineural hearing loss.
The cochlea is filled with fluid where tiny sensory hairs are attached to nerve cells. When the hair cells are damaged, they are no longer able to transmit all the information received. “We are born with a bunch of hair cells and almost immediately we start shedding them,” says Dr. Adunka.
Causes of sensorineural hearing loss can include:
- Aging. “We all lose our hearing,” says Richard S. Tyler, Ph.D., professor and director of audiology in the department of otolaryngology and the department of communication sciences and disorders at the University of ‘Iowa. “For some, it starts at 50; for some, it starts at age 70. Genetics play a large role in how likely you are to lose your hearing and the rate at which you lose it. “Some people are genetically predisposed to hearing loss,” says Dr. Adunka.
- Exposure to loud or chronic noise. Chronic noise exposure is linked to aging because the longer you live, the more likely it is that frequent exposure to noise in the workplace or for recreational purposes will cause cumulative damage to hair cells in the inner ear. and will cause a noticeable hearing loss. However, even a single exposure to very loud sound can cause hearing loss. Among adults aged 20 to 69 who said they had been exposed for five years or more to very loud noises at work, about 18% had speech rate hearing loss in both ears, compared to only 5, 5% of adults with the same problem who reported no occupational exposure to noise.
- Medications. Over-the-counter and prescription drugs can damage your hearing. Known as ototoxic drugs, these include quinine-based antimalarials, high-dose aspirin, certain types of antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), certain chemotherapy drugs, and diuretics. handle. As with loud noise, ototoxicity impacts some people more than others, so be sure your doctor monitors the possible effects on your hearing if you take any of these medications.
- Diseases. A wide variety of diseases and conditions can negatively affect hearing. These include childhood illnesses like mumps and meningitis. Other conditions and diseases that can contribute to hearing loss include autoimmune diseases, diabetes, high blood pressure, HIV/AIDS, iron deficiency anemia, migraines, multiple sclerosis (MS) and of thyroid. One of the most recent diseases to come under scrutiny as a possible cause of hearing loss is Covid-19, as it can infect the brainstem, although researchers have not yet been able to figure it out. definitive conclusions.
- Autoimmune inner ear disease (AIED). AIED is not a common condition, but when it occurs, it is the body’s own immune response that damages both inner ears and possibly parts of the middle ear, leading to hearing loss. It can be associated with a systemic autoimmune disease, but it can also appear on its own.
- Meniere’s disease. This rare disorder that has no known cause can lead to hearing loss over time. It affects the inner ear and symptoms include episodes of vertigo or lightheadedness and ringing in the ears (tinnitus), as well as a feeling of pressure in the ear.
Mixed hearing loss
It is possible that hearing loss is caused by both conductive and sensorineural factors. When this is the case, we speak of mixed deafness.
Causes of mixed hearing loss include:
- Otosclerosis. In about a third of cases where the three small bones that conduct sound in the middle ear become deformed, there is also sensorineural hearing loss. This is due to the condition extending into the inner ear and affecting the cochlea and associated ligament.
- Head and/or brain injury. The part of the damaged ear depends on the nature of the injury. Many traumatic brain injuries sustained in the military are the result of blasts that damage the inner ear, but can also impair auditory processing, blood flow, muscles, or nerves in the head and neck. It is also possible for extremely loud blasts to rupture the eardrum, which is part of the middle ear, although this is rare.