Hearing Loss - Symptoms, Causes, Treatment, and More

What are the types of hearing loss?

Hearing loss refers to a decrease in sensitivity to sounds that are audible to those with normal hearing. There are a few key types to be aware of:

Conductive hearing loss is due to the sound signal not being directed properly to the inner ear from either the outer or middle ear. “This type of hearing loss is not typically a complete deafness, but a reduction in the loudness of sounds,” according to Christine Pickup, AuD, Doctor of Audiology, Rupert. Among the causes of conductive hearing loss are allergies, earwax blockage, and a perforated ear drum among others.

Causes can include fluid in the middle ear space from congestion due to colds, perforations (holes) in the eardrum, benign tumors, impacted cerumen (earwax), and infection in the outer ear canal (often called Swimmer’s Ear). Another common cause is otosclerosis, or a stiffening of the chain of bones in the middle ear.

Sensorineural hearing loss (SNHL) occurs in the inner ear itself or along the auditory pathway as sound signals travel to the brain. “The most common form of sensorineural hearing loss is age-related hearing loss, also known as presbycusis,” explains Washington, DC-based audiologist, Gina M. Crovato, AuD. It can also be triggered by excessive exposure to loud sounds, certain medications, head trauma, and other factors. Regardless of the cause, SNHL is usually permanent and often involves a reduction in the ability to understand speech.

Mixed hearing loss is a combination of both conductive and sensorineural hearing losses, and often reflects two or more different conditions affecting the inner ear as well as either the outer or middle ear.

Sometimes there is a single cause for the mixed hearing loss, such as when head trauma from a blast injury damages the different parts of the ear.

Mixed hearing loss can also be caused by separate issues. “For example, if a patient has underlying SNHL due to aging, and then gets an ear infection on top of that, now they will have a mixed hearing loss,” explains Rosette R. Reisman, AuD, an audiologist in New York.

Auditory processing disorders can also trigger hearing loss that occurs in the pathway to the brain or in the processing areas of the brain responsible for hearing and language. For example, a stroke can be the source of this kind of hearing loss.

Lastly, if you have a “normal” result on the hearing test (or audiogram), but still struggle to hear in background noise, you may be suffering from a recently-identified form of hearing loss known as hidden hearing loss, which was initially attributed to cochlear synaptopathy. Recent research, however, suggests that Central Auditory Processing Disorder (CAPD) may be the most common cause of hidden hearing loss.

Hearing loss in children

The stereotypical image of a person with hearing loss is a grandparent whose hearing has faded over the years. But according to the Hearing Loss Association of America (HLAA), 2 to 3 out of every 1,000 children in the United States are born with a detectable level of hearing loss in one or both ears. Furthermore, an estimated 1 in 5 American teens experiences some degree of hearing loss.

How do I read a hearing test?

Hearing tests are complex ways to determine your abilities, including such factors as intensity (what we perceive as volume) and frequency (what we perceive as pitch).

An audiogram is a graph of pitch along the X-axis and volume along the Y-axis. The low pitches are on the left side of the graph and the high pitches on the right side, like a piano. The soft sounds are at the top and loud sounds at the bottom, so the higher you are on the scale the more sensitive you are to the sounds.

While these graphs are complex to read, here’s an important bit of information: The cutoff for what’s considered normal hearing is 20 dB HL or 25dB HL, so any of the scores you see on the graph that are at or above that are within normal limits. “Any of the scores you see below the 20 dB HL line are considered a hearing loss,” according to audiologist, Evan Grolley, AuD.

Your audiologist can help break down the test results, explain why you are experiencing communication problems, and provide recommendations.

What are the consequences of untreated hearing loss?

Approximately 15% of American adults (37.5 million) aged 18 and over report some trouble hearing. According to the Hearing Loss Association of America (HLAA), only 1 in 5 people who would benefit from a hearing aid actually uses one. That’s a cause for concern:

• In general, those with hearing loss who do not wear hearing aids are more likely to report feelings of depression, loneliness, worry, and dissatisfaction with family life.
• Difficulty communicating often leads to loss of interest in participating in social activities.
• Safety is also a concern for those with hearing loss who cannot hear alarms, the phone, the doorbell, or someone entering their home. Nor can they successfully converse over the phone. These create barriers to maintaining an independent lifestyle.
• Strong associations have been found linking hearing loss to reduced cognitive function. Researchers do not suggest that hearing aids can prevent dementia, but the use of amplification may reduce or delay the disease’s impact.
• Individuals with hearing loss who do not wear hearing aids report more fatigue due to the extra effort put forth in trying to listen and understand all day.

“Unaddressed hearing loss leads to reduced awareness of the environment, reduced ability to understand speech, and reduced communication which is often the pillar of relationships and many aspects of life,” explains Jodi Baxer, AuD, clinical assistant professor at OSU.

Additionally, research continues to link hearing loss to a large number of chronic illnesses, including diabetes, heart disease, cancer, arthritis, migraine, osteoporosis, and more. You can read more about this in the article Chronic Illness and Hearing Loss: What You Need to Know.

How is hearing loss treated?

Treatment depends on the type and degree of hearing loss an individual has been diagnosed with. For conductive hearing loss, it may be possible to remove or repairing whatever it is that is preventing the conduction of sound.

For sensorineural loss (the most common type, with up to 90% of all cases), hearing aids are the most common treatment. Individuals with severe cases are often candidates for cochlear implants.

The future of hearing loss treatment

Scientists are busy developing cutting-edge pharmaceuticals to restore natural hearing ability. And some potential treatments are already in clinical trials. One such treatment is being developed by Frequency Therapeutics, a biotechnology company in Massachusetts.

Dr. Carl LeBel, the Chief Development Officer, spoke to HearingTracker in a podcast about the development of a novel hearing loss treatment drug, FX-322. “We're taking a regenerative medicine approach. We're acting on cells that are already in the cochlea,” explained LeBel.

How can I cope with my hearing loss?

If you have hearing loss, consult an audiologist. They can likely offer options for mediating hearing loss.

Also address the emotional aspects of living with a hearing loss. Baxter explains that “Most individuals who have a newly acquired hearing loss have to go through a grieving process just like any other type of loss, disease, or disorder.”

It’s also important to be a good self-advocate and create a good support system. For instance, be open with family members, friends, and co-workers about your hearing loss and what they can do to help with communication. Seek out a local support group to meet and talk with others who have gone through the same experience.

Does hearing loss cause dementia?

There is currently no evidence to show that hearing loss causes dementia. However, this is still an open question. Researchers are looking into three ways in which hearing loss may lead to dementia:

1. Changes in the brain. Prolonged hearing loss appears to lead to structural and functional changes in the brain, particularly the temporal lobe. With hearing loss, a degraded auditory signal and reduced stimulation from the cochlea may lead to reorganization in the brain and, with prolonged auditory deprivation, ultimately, brain atrophy.
2. Cognitive load. The effort and processing ability required to overcome a degraded auditory signal from age-related hearing loss may pull vital cognitive resources away from general cognitive processing in older adults who demonstrate decline in cognitive ability, thereby exacerbating symptoms and limiting reserve to cope with existing brain pathology (e.g., amyloidosis, neurodegeneration) that leads to dementia .
3. Risk for decreased social engagement. We know individuals with hearing loss frequently decrease their engagement in social activities or have an impaired social or emotional connection with others, which may lead to social isolation or feelings of loneliness – known risk factors for dementia.

Can hearing loss be prevented?

A common cause of hearing loss is loud noise, which can cause both temporary and permanent hearing loss. “The best way to prevent hearing loss is to reduce your exposure to loud sounds,” recommends Audiologist, Shaeleen M. Fagre, AuD, an audiologist and Audiology Clinical Supervisor in the Davis Speech-Language-Hearing Center at the University of Minnesota.

Avoiding damagingly loud sounds at work and home is a key preventive measure. Your environment is deemed too loud if you must raise your voice to be heard, you can't hear someone three feet away from you, speech around you sounds muffled after you leave the noisy area, and you have pain or ringing in your ears after exposure to noise.

How common is hearing loss?

Hearing loss is the third most common physical health problem in the United States, behind such common ailments as heart disease and arthritis. Approximately 15% of Americans adults (or 37.5 million people) report some difficulty in hearing, with those aged 60-69 demonstrating the greatest degree of hearing loss. Men aged 20-69 were found to be almost twice as likely as women to have hearing loss.

Who are some celebrities with hearing loss?

Oscar-winners Whoopi Goldberg and Jodi Foster as well Rob Lowe have spoken about their experiences with hearing loss. Former President Bill Clinton noticed his hearing decline with age and now uses hearing aids.

As these celebrities show us, you can still live a full and successful life despite the challenges of living with hearing loss.

If you experience any symptoms of hearing loss, or are worried about your hearing, don’t hesitate to make an appointment with a licensed audiologist to have a comprehensive hearing evaluation. An audiologist can help you manage your hearing loss by determining the best treatment option for your needs.