Hearing gives us the means to listen and connect with one another and experience the world around us through sound. Because our sense of hearing lets us collect, process and interpret sounds without conscious effort, it’s easy to take this extraordinary ability for granted.
Our ears are a complex system of sensitive fluids and delicate nerve endings. Tiny specialized cells in the inner ear (or cochlea) known as hair cells convert the vibrations of sound waves into electrical signals that the brain can interpret. These fragile hair cells are one of the key components of the auditory system and when they’re damaged, it can lead to permanent hearing loss.
Two Main Types of Hearing Loss
Known causes of hearing loss in adults are divided into two main types — conductive and sensorineural. Conductive hearing loss happens when sound is unable to pass freely to the inner ear. This type of loss is usually due to some sort of physical damage or blockage, including:
- malformation of inner or outer ear structures
- fluid in the middle ear due to a cold or allergies
- perforated eardrum
- benign tumors
- impacted earwax
- ear infections
- foreign object in the ear
But the leading cause of hearing loss in adults is sensorineural hearing loss – due to the effects of aging on the auditory system. It's not just getting older that causes this loss, though. "Very rarely do I see age-related hearing loss. . . 99 percent of the time the patient has a comorbidity (a second reason) for hearing loss," says Dr. Julie Link, founder of Denver-based audiology practice Audiology Method.
Link says that these comorbidities tend to be illnesses or conditions that are more common with age, but also notes that people often start to experience hearing loss in their 20s or 30s and don't pursue treatment for the condition until later, when the effects are more noticeable.
Whether you're already dealing with some hearing loss or just want to protect your ears as you age, what follows are 10 common causes of hearing loss in older adults to be aware of.
Noise-induced hearing loss is a form of sensorineural healing loss caused by prolonged exposure to loud noise. In some cases, a single brief burst of an extremely loud sound like an explosion or blast of a firearm can cause instantaneous and irreversible damage.
But often, noise-induced hearing loss results from a culmination of long-term exposure to everyday sounds like traffic, construction work, machine work, loud music and even noisy office environments.
Annette Mazevski, a doctor of audiology and manager or Technology Assessment at Oticon notes that there’s a category of drugs that are toxic for the ear. Ototoxicity, or ear poisoning, results from exposure to drugs or chemicals that can damage cells of the inner ear.
"There are more than 200 ototoxic drugs (available both over-the-counter and by prescription), with one of the most commonly used one being aspirin. Very high levels of aspirin in the blood can have side effects that can cause hearing loss,” she says. “Hearing loss resulting from ototoxic drugs is usually reversed once an individual stops taking the drug, but sometimes the hearing damage can be permanent."
Cisplatin, the chemotherapeutic medication widely used in the treatment of of cancerous tumors, is severely ototoxic. Cisplatin and similar cancer drugs contain heavy metals that damage the plasma sheath that protects nerve endings in the ear and the hair cells themselves. Hearing loss resulting from chemotherapy incrementally worsens even after therapy is over, affecting patients for many years.
Having diabetes can be another risk factor for hearing loss that many are unaware of. "When most people think about complications of diabetes, hearing loss isn’t usually considered,” says Dr. Leisa Lyle-Deleon, a doctor of audiology. “However, research shows that people with uncontrolled type 1 or type 2 diabetes are twice as likely to experience hearing loss. As a result of elevated blood glucose levels, one in three people with diabetes will experience some degree of hearing loss."
5. Sleep Apnea
Sleep apnea is a common disorder affecting millions of Americans. Symptoms include heavy snoring with periods of gasping or snorting. This sleep issue is more of a systemic and chronic disease than just something that happens when you're sleeping, and it affects multiple organs.
Because sleep apnea causes inflammation and abnormal blood vessel function, the sensitive cells in the auditory system can become damaged, leading to permanent hearing loss.
6. Heart Disease
Heart disease causes plaque buildup on the artery walls, making it harder for blood to flow through the circulatory system. The resulting diminished blood flow seriously affects all the organs in the body, including auditory system organs.
The inner ear is extremely sensitive to blood flow. If blood flow is inadequate, interrupted or if the vessels suffer a trauma, the result can be permanent hearing loss. In fact, because the nerves in the inner ear are so fragile, they may actually be the first organs affected by the complications of heart disease.
Smoking cigarettes affects hearing health in a variety of ways. Mazevski notes that "research has shown that adults who smoke tobacco or have regular tobacco smoke exposure show increased difficulty hearing with background noise compared to non-smokers."
Cigarettes contain chemicals including formaldehyde, arsenic, ammonia, hydrogen cyanide and nicotine that can cause damage to living cells. Plus, nicotine and carbon monoxide deplete oxygen levels and constrict blood vessels throughout the body, including those in the cochlea. Nicotine also interferes with neurotransmitters in the auditory nerves that are responsible for transmitting sound and speech information to the brain.
Healthy blood flow and oxygen contribute to the health of delicate cochlear hair cells. Because obesity puts an enormous strain on the walls of your capillaries, oxygen and nutrients are transported to these hair cells less efficiently.
And since excess weight makes it difficult for your heart to pump blood throughout your body, obesity can also cause high blood pressure, which is another contributing factor of hearing loss.
Chronic stress can take a toll on every part of the body. Chronic stress can slow blood flow to these delicate areas, resulting in damage when blood stops flowing effectively to the ears. An overproduction of adrenaline can also reduce or even stop blood circulation in the inner ear. This stoppage of blood flow can result in sudden, severe and irreversible hearing loss, often in one ear.
A study published in the Journal of Clinical Endocrinology & Metabolism shows that those with osteoporosis are 76 percent more likely to develop sudden onset hearing loss.
“Sudden hearing loss symptoms can feel mild, like plugged ears after getting off an airplane, making it seem like less of an emergency situation," says doctor of audiology Dr.Leisa Lyles-DeLeon. But though these symptoms may be mild, the doctors says that anyone with osteoporosis should treat these symptoms seriously and see an audiologist, because early detection can result in reversal of the issue.
In fact, the experts all agree: some hearing loss can be treated, so if you're struggling to hear the television or conversations with others, don't chalk it up to your age and move on. See a hearing health professional to find out if you can get back some of the functionality that’s been lost.