Contributed by Joy Victory, Editor-in-Chief, Healthy Hearing
When a person has hearing loss in both ears, but one ear is worse than the other, this is called “asymmetrical hearing loss”. Other names include “interaural asymmetry” and “asymmetric sensorineural hearing loss”.
For most people with hearing loss, the left and right ears have similar hearing ability patterns. If your hearing test reveals asymmetric hearing loss, your hearing care professional may refer you to an ENT (ear, nose and throat) specialist before they fit you. This is because having different levels of hearing ability between the ears could signal an underlying medical condition.
Let’s look at the causes of uneven hearing loss between the ears and how hearing care professionals can help with treatment.
Mild asymmetric hearing loss is normal
During a hearing test, your hearing specialist, usually an audiologist or audiologist, will carefully measure your ability to hear volume and frequency (pitch) in each ear. The results are then mapped onto an audiogram. The right ear is represented by a red line and the left ear by a blue line. The lines drawn for both ears should be relatively similar for each ear, as shown here:
When is it of concern?
If there’s more than about 10 decibels (dB) different across at least three frequencies, “there’s probably a specific reason,” explained audiologist Mandy Mroz, AuD, and president of Healthy Hearing. “A hearing care professional should order more tests if they cannot determine why there is a difference between the two ears.”
The same goes for tinnitus, or ringing in the ears. If it’s worse in one ear, it should be checked out by a doctor. Many of the same conditions underlying asymmetric hearing loss can cause asymmetric tinnitus, Mroz explained.
Causes of Asymmetric Hearing Loss
There are many possible causes, ranging from common (noise damage) to rare (tumors). Often there is also an overlap with a person with multiple issues causing uneven hearing loss between the ears. This is why a thorough diagnostic workup by a physician is so important. Let’s look at the possible reasons:
Exposure to shooter’s ear and other noises
There may be an obvious “lifestyle” reason why one ear is worse than the other. Sometimes it’s work-related. For example, military service members and hunters are at risk for “shooter’s ear” from exposure to gunfire, a unique type of noise-induced hearing loss that affects one ear more than the other. ‘other.
Ear infection or inflammation
Have you had a cold or a sinus infection recently? Have you noticed an earache? This can temporarily worsen hearing in one ear more than the other. But if you also suffer (or have suffered) from chronic middle ear infections, whether as a child or an adult, you may develop permanent patchy hearing loss due to weakened bone structures.
Earwax impaction, or impacted earwax, can also cause different levels of hearing loss in each ear. Earwax buildup that affects hearing, causes pain, and needs to be treated by a doctor is quite common. Often the cause is people trying to clean their ears the wrong way.
It is easy for a hearing care professional to spot impacted earwax. If you suspect that you are suffering from hearing loss due to earwax, you should first consult your GP; he or she might recommend home remedies to remove excess earwax before trying a professional ear cleaning.
Ménière’s disease is an autoimmune disorder that disrupts the pressure in the inner ear, usually in only one ear. This leads to dizziness, ear congestion, tinnitus, and fluctuating hearing loss that usually gets progressively worse over time. This is one of the most common ways to develop different levels of hearing between ears.
Otosclerosis and other bone disorders
Otosclerosis causes the bones in the middle ear to harden and lose flexibility, reducing their ability to vibrate and affecting sound quality. It often runs in families and is more common in young white women. Another condition, known as congenital stenosis, narrows the ear canal and can make hearing loss worse in one ear than the other.
Although rare, tumors can lead to differences in hearing ability between ears. The most common type of tumor that can cause hearing loss, called vestibular schwannoma or acoustic neuroma, is benign and slow growing. They affect hearing by growing on the nerve leading from the brain to the inner ear. Since these nerves are responsible for both balance and hearing, acoustic neuromas can cause both dizziness and hearing loss. If you have these symptoms, you should consult your doctor.
A combination of causes or “dual diagnosis”
Some people have hearing loss for more than one reason and suffer from both sensorineural and conductive types of hearing loss. For example, if you suffered a traumatic brain injury on one side of your head and later develop age-related hearing loss, you may have hearing loss in both ears, but your hearing in the ear injured is worse.
Sudden unilateral hearing loss
Often occurring without warning, sudden sensorineural hearing loss in one ear should never be ignored. It’s considered a medical emergency. It can have many causes, but one of the most common reasons is a viral infection of the auditory nerve. See your doctor right away if you suddenly have trouble hearing in one ear.
How Asymmetric Hearing Loss Affects How You Hear
This will vary greatly depending on your particular situation and degree of hearing loss. If one ear is significantly worse than the other, for example, you may experience the “head shadow” effect and other unique issues that come with single-sided hearing loss, also known as single-sided deafness. .
Hearing aid fitting for asymmetric hearing loss
Your treatment options will depend on the cause and degree of your hearing loss. Most likely, hearing aids, bone-anchored hearing aids, or cochlear implants will be the recommended treatment.
This is a more complicated form of hearing loss, and it may take some trial and error to find the right hearing
assistance solution for you. The goal is to find a solution that balances the signals arriving at each ear so that you can perceive the sound as “normally” as possible. The difficulty will increase with the difference in hearing ability between the ears.
With modern programmable hearing aids, an audiologist may be able to customize the settings for each side to compensate for the worse ear. However, if the hearing loss is too great in one ear (or vice versa, one ear is completely normal), bone-anchored hearing aids might be a better solution.
For this reason, it is wise to consult an experienced audiologist who works in tandem with an ENT.
Patience is the key
If you need a hearing care professional, searching our directory of hearing clinics is a good first step.
“Be patient when trying hearing aids for asymmetric hearing loss,” Mroz said. “You’ll probably need more tweaking to get the balance set for your single loss, and it will take your brain a little longer to gather the amplified signals in your head. But it will be worth it. Plus health benefits of wearing hearing aids, it will become easier to localize sounds when your asymmetrical hearing loss is treated.”