- What is age-related hearing loss?
- What are the symptoms?
- Why do we lose our hearing as we get older?
- Can I prevent age-related hearing loss?
- How can I tell if I have a hearing problem?
- What should I do if I have trouble hearing?
- What treatments and devices can help?
- Can my friends and family help me?
- What research is being done?
Hearing impairments are more common as we age, and it is a part of the process. This has been described in medical literature, and it is known as presbycusis.
Multiple factors contribute to the development of sensorineural hearing loss in elderly individuals. In time, they result in gradual hearing loss in both ears, which affects their quality of life.
This problem was initially described back in 1899 and is still studied in current literature. It is a significant problem because many older adults experience this problem, which slowly adds to their disabilities. It is a cause of isolation in older adults by restricting them from using the phone and isolating them in family gatherings and other social opportunities.
In this article, we’re exploring the essential aspects of age related hearing impairment. We’re reviewing why it does happen, how we can prevent this problem, and what to do if it happens to you.
What is age-related hearing loss?
As the name implies, age-related hearing loss refers to reducing sensorineural hearing capacity as a part of the aging process. The organ of hearing is the inner ear. It is a very complex structure filled with fluid and found inside of the temporal bone.
The inner ear includes two main parts: the vestibular system and the cochlea. The former is important for balance, and the latter is essential for auditory function. They are both carried to the brain through the auditory nerve, and each one goes through individual nerve pathways to the auditory cortex and other areas of the brain.
Hearing loss can build-up over time for several reasons. Not all of them are considered an age related hearing loss. For example, there is sometimes a hearing impairment due to a lesion to the inner ear structures. In other cases, the agent responsible would be a toxic agent or a drug. But none of them is considered sensory presbycusis or neuronal presbycusis. This condition is entirely symmetrical. It is also slow-progressing, and the causes are not as easy to trace (1).
What are the symptoms?
The presentation of age-related hearing loss is different for each patient. Each one of them has various changes in their neural networks and cochlear structures. However, they usually experience a combination of these symptoms (2, 3):
- Failure to understand rapidly spoken language, which is usually one of the first symptoms. It is particularly important when unfamiliar vocabulary or complex grammar is used.
- Difficulty to understand in a distracting or noisy environment. This symptom should be evaluated carefully. Patients may also have a cognitive impairment affecting their capacity to focus in this type of environment.
- Increased difficulty in understanding spoken language, especially from women. Women have a higher pitch than men, and patients with presbycusis have more difficulty hearing high-pitch sounds.
- A difficulty to localize sounds once they perceive them. This problem becomes worse over time as patients grow older.
- Strong reliance on lip-reading to understand spoken language. Some patients with age-related hearing loss become real experts in lip reading.
- Speech discrimination is sometimes normal when no background noise is present.
- The hearing function can be recovered impressively using a hearing aid to increase gain in higher-pitched sounds.
- In some patients, hearing loss leads to social withdrawal. This sometimes triggers depression and other psychiatric conditions.
- As the hearing deficiency progresses, patients start hearing a ringing sound in the ears. It can also be a buzzing or clicking sound that is not real, known as tinnitus. It is usually symmetrical (heard in both ears at the same time).
It is important to note that age related changes (presbycusis) is an exclusion diagnosis. In other words, doctors should rule out other identifiable causes of hearing loss before diagnosing presbycusis. So, before any other diagnosis, it is essential to make a complete physical exam. Sometimes it is a cerumen impaction or a more complex problem like otosclerosis.
Why do we lose our hearing as we get older?
The exact causes of hearing loss as we get older are not completely understood. Similar to cancer and other chronic health problems, presbycusis is multifactorial.
Multiple risk factors contribute to the same problem, and there is not a unique cause. Instead, there are numerous proposed causes or risk factors. Some of them are listed below (1, 3):
- Atherosclerosis: It features the formation of fat plaques in the arteries. They slowly build up in the artery walls and reduce the volume of blood to the cochlea. The availability of oxygen becomes compromised, and the tissue starts creating free radicals. When this continues for a long time, these free radicals destroy the structures in the inner ear. There’s also genetic damage in the mitochondrial DNA. Altogether, these lesions and progressive damage contributes to presbycusis.
- Diabetes Mellitus: Diabetes is another cause of presbycusis. It accelerates the formation of atherosclerotic plaques, with the damage mentioned above. Diabetes also intervenes with microcirculation and the oxygenation of the inner ear. Additionally, it causes endothelial hypertrophy and proliferation of the intima layer. This endothelial problem also contributes to the perfusion problem of the cochlea. Other studies showed changes in the auditory brainstem of individuals with diabetes. This may also contribute to presbycusis in diabetic elderly patients.
- Dietary habits: A diet high in natural antioxidants slow down the progression of presbycusis. As noted above, free radicals play an important part in damaging mitochondrial DNA and causing lesions in the inner ear. Antioxidants act as free radical scavengers, neutralizing these dangerous substances.
- High noise exposure: Patients exposed to noise due to occupational causes or any other have an increased incidence of presbycusis. This is not a single lesion but accumulated lesions over time that speed up this condition’s progression.
- Genetic causes: There is a genetic susceptibility for the development of age-related hearing loss. In these cases, patients usually develop other sensory impairments, including visual acuity, the sense of taste, smell, and most probably the patient’s balance. There is also an increased susceptibility to certain chemicals and drugs that may contribute to the condition.
Can I prevent age-related hearing loss?
After understanding the risk factors for age-related hearing loss, we can also figure out different prevention strategies as listed below (4):
- Reducing noise levels in the environment: The easiest way to prevent this age change is by reducing environmental noise levels. The safest levels of noise are around 70 dBA or less. Sounds higher than 85 dBA can cause inner ear damage when maintained for a long time. Many portable devices measure background noise levels. We also have access to mobile apps to measure your earphone noise levels. They can be used to reduce the incidence of age-related hearing loss.
- Augmented Acoustic Environment: This is another technique tested to reduce the incidence of presbycusis. Augmented Acoustic Environment is a background noise with specific sound waves. It is audible but does not cause a threshold shift. According to studies, exposure to this background noise reduces the progression of age-related hearing loss. There is no known mechanism, but different proposed causes. Augmented Acoustic Environment causes blood flow changes in the stria vascularis and excitation changes in the cochlea. It apparently increases the antioxidant potential in the inner ear, as well.
- Antioxidant enhancements: As noted above, a diet with antioxidant sources can be useful to prevent age-related hearing loss. It slows down the progression or prevents the onset of presbycusis. The most important antioxidants are vitamin E, vitamin C, and melatonin. They have a free radical scavenger function that protects the inner ear. Acetyl-L-carnitine supplements may also be used to protect the mitochondrial membrane from free radical damage.
- Calorie restrictions: Obesity is by itself a source of disease. Thus, calorie restriction diets have been found useful to prevent the onset of several conditions. According to different studies, neurodegeneration slows down in calorie-restricted individuals. This has different mechanisms, including oxidative stress reductions, reduced metabolic rate and dietary fat levels, and improved glucose regulation. Altogether, it apparently causes a decrease in hearing loss deficiencies and a prolongation of the lifespan at the same time.
- Salicylates: According to studies, salicylates could be used to prevent ototoxicity from drugs such as gentamicin or cisplatin. They cause a temporary hearing deficiency, but at the same time, protects individuals from further damage. However, this has not been tested clinically, and there are only animal models.
How can I tell if I have a hearing problem?
One way to tell if you have a hearing problem is by evaluating the list of signs and symptoms above. If you have two or more symptoms, your case should be evaluated by a doctor. That would be the only way to know if you have a hearing problem accurately.
There is audiometric testing under controlled conditions and with different tones. In the case of presbycusis, doctors recommend a particular type. It is called audiometric pattern evaluation. It is also vital to perform speech discrimination tests to diagnose presbycusis.
More evaluation and additional causes should be investigated in patients with asymmetric findings. For example, a patient with a hearing difference of 10 dB in the right and left ear. In these cases, patients may undergo further studies to determine if the auditory information is reaching their brain or not. It is also essential to evaluate the structure of the inner ear.
This can be done through a series of imaging tests, including a CT scan or MRI. Laboratory analyses can be useful as well to rule out autoimmune causes of hearing loss (2, 3).
What should I do if I have trouble hearing?
If you suspect or feel sure that you have hearing problems, it is important to check yourself with a doctor. More specifically, you can talk to an otolaryngologist or an audiologist.
Other specialists that may help include a neurologist and some psychiatrists. If you do have a problem hearing, as noted by one or more hearing tests mentioned above, the next step is usually rehabilitation. However, consider that rehab for presbycusis is challenging, long-lasting, and complex. It takes a lot of patience and considerable time.
There is no prescribed dietary restriction if you have trouble hearing. But you may want to reduce your caloric intake and increase your antioxidant intake for the reasons listed above. Alternatively, you can also use antioxidant supplements. They are not a treatment but can help you slow down the progression of presbycusis. It is also important to prevent exposure to sustained loud sounds for the same reason.
After presbycusis is diagnosed, patients should also undergo follow-up care. An audiologist or otolaryngologist is usually the specialist that provides such follow-up. They will monitor the patient’s hearing threshold and record any changes as time passes.
Even with prevention strategies, we can expect some progression of the disease. The most common rate of hearing loss is near 1 dB every year. There is no absolute cure for the disease, but we do have devices and other treatments. They are useful to reduce the impact of presbycusis in the patient’s daily life. However, they do not provide a cure (2, 3).
What treatments and devices can help?
No medication has been found useful to treat or slow down the progression of presbycusis. As noted above, there is no absolute cure, but some devices and treatments can be helpful. Here’s a comprehensive list summarized in only a few paragraphs (2,3,5):
- Amplification devices: They are most commonly known as hearing aids. These devices are essential elements for the rehabilitation of presbycusis patients. They can be particularly difficult to use in patients with visual difficulties or arthritis. Even with these amplification devices, patients may still have trouble making out the speech in noisy environments. Only an audiologist should program and test these hearing aids to adjust for each patient.
- Assistive listening devices: These devices can be handy to amplify the sound of a telephone. This and other devices can be connected to a headset. This is similar to an amplification device but has a simpler approach.
- Cochlear implants: In some cases, patients with presbycusis may need an implant directly applied to the cochlea. This is the most appropriate treatment in patients with cochlear alterations. However, they need to have their neurologic pathways and spiral ganglion neurons in optimal conditions. It is only recommended when amplification devices do not work.
- Lip reading: As noted above, lip reading and gesticulate speech discrimination are common techniques used by these patients. They often become very good at lip-reading, but this requires a lot of practice. It is an auxiliary method when no hearing aid is yet available for the patient.
Can my friends and family help me?
Communication is a matter of two or more people. Thus, friends and family can play a great deal in helping these patients cope with age-related hearing loss.
For example, we have mentioned how important lip reading is for presbycusis patients. So, it is imperative to speak face to face. If you want to call this person, prefer video calls to the usual phone call.
Also, if you’re a relative of someone with hearing problems, you may want to slow down your speech and gesticulate appropriately to facilitate lip-reading. Instead of using long and complex sentences, use simple words with simple grammar. Say the same thing in a short sentence and rephrase your statements as much as needed.
It is also essential to reduce environmental noise if you really want to help. If you’re about to meet in a social gathering, try to find a seat away from the noise or in a less crowded area. In your house, shut down the television or radio, and repeat what you just said. Avoid speaking with your mouth covered or chewing food. And use more low-pitched tones instead of a high pitch. These recommendations can be beneficial to communicate with these patients.
What research is being done?
Strikingly, presbycusis has been known for many years, and we still don’t understand the exact causes. Maybe that’s one of the reasons why there’s no current treatment for this condition. However, recent research is usually focused on understanding the pathologic basis of this problem.
In a recent review published in the Journal of Neuroscience Research, the researchers show the most recent studies on age-related hearing loss. There are currently a few candidate genes under research. They apparently cause a higher incidence of age-related hearing loss. By identifying them, we can detect high-risk patients and maybe target them in gene therapy in the near future.
For example, variants in a gene known as SPATC1L cause a structural change in the proteins of cochlear structures in the inner ear. Similarly, other mechanisms and risk factors are under research to provide a targeted approach to prevent instead of treating this progressive disability (1).