“Most people with unilateral hearing loss or loss in one ear compensate well. The perception of sound in the usable ear becomes stronger. However, the one magic trick the brain cannot perform is to help determine where the sound is coming from. This is called sound localization. It is very important that if you know someone with unilateral hearing loss, or if it is you, to be very aware of the surroundings. It may be possible to hear the car coming, but not from where it is coming from.” - Drew Sutton, MD, Board-Certified Otolaryngologist
While people don’t put much thought into the process of hearing, it is ultimately an important process that our bodies get a lot of information from. Information such as distance and direction can be conveyed thanks to binaural cues.
The brain can take the slight differences in input from a sound source and place the sound in space with two ears. Even if you have your eyes closed, placing where a sound came from is easy, thanks to having two fully functional ears.
Hearing impairment can be caused by a variety of factors such as loud noise exposure, head trauma, genetics, and other external factors. While there are many causes of hearing loss, hearing loss also varies upon the person.
Some symptoms and signs to look out for include earwax buildup, inflammation, and swelling.
While traditional hearing loss can have its downsides, hearing loss in one ear can be particularly difficult. The brain needs to adjust for differences in hearing and understand how this change translates to having accurate binaural cues.
Asymmetrical hearing loss, also known as one-sided hearing loss, has many potential causes ranging from an ear infection to more serious problems like meningitis and mumps. Below is a closer look at three causes and possible treatments for hearing loss in one ear, as well as other information regarding one-sided hearing loss.
Meniere’s disease is a complex disorder that has to do with the fluid balance of the inner ear. The inner ear has two separate cavities filled with fluid, and in the case of Meniere’s disease, one of these compartments swells and contributes to the tinnitus, hearing loss, and feeling of fullness in the ear. In extreme cases, the ear may cause a dizzy spell which then requires time to heal properly.
Meniere’s disease typically shows up later in life and only affects one ear. Because the progression is typically slow, the effects on the binaural cues are smaller, but it still impacts your ability to hear effectively.
Treatments for Meniere’s Disease
Meniere’s disease causes a unique form of hearing loss that typically only affects one ear. The underlying cause of hearing loss due to Meniere’s is an abnormal fluid buildup in the inner ear known as the cochlea.
Treatments for Meniere’s revolve around reducing vertigo symptoms and avoiding fluid accumulation on the cochlea. Anti-nausea and motion sickness medications may be a part of treatments to help reduce vertigo symptoms during an attack. For preventing fluid accumulation in the cochlea, a diuretic may be prescribed in addition to a low sodium diet.
Hearing loss in Meniere’s can be permanent. Assistive devices such as hearing aids are prescribed to minimize the effects of hearing loss. Many prescription hearing aids, however, can be costly, potentially costing over a thousand dollars. Over-the-Counter hearing aids, on the other hand, are much more cost-efficient and have many of the same features as those sold at the audiologist’s office.
As a kid, you most likely had at least one ear infection. Children can be more prone to ear infections due to a smaller eustachian tube in the ear canal that can get clogged much easier than when fully grown. The eustachian tube connects the middle ear to the back of the throat near a structure known as the adenoids.
When children get sick, the adenoids can become inflamed and close off the eustachian tubes. This, paired with the entrance of bacteria or viruses, can lead to a middle ear infection.
The truth is that a middle ear infection is just one way that bacteria and viruses can infect the ears. These pesky foreign bodies can also infect the inner ear and have the capability of causing lasting hearing loss. Cochlear infection occurs less frequently, but it is one of the few forms of sudden sensorineural hearing loss that can occur when it does.
Treatments for Ear Infections
Typically, ear infections resolve themselves, but in some instances, they may need antibiotics if a bacterial infection won’t resolve independently. In cases of chronic ear infections, a child might need a procedure known as tympanostomy, which inserts a draining tube in the eardrum.
This tube allows fluid to exit the middle ear and effectively mitigates the potential for pressure differentials between the middle and outer ear. It also significantly reduces the chance of more recurrent ear infections.
Unfortunately, there is no treatment available for viral infection of the inner ear. The best that can be done is supportive care during the infection and finding ways to regain lost functions. Because this can result in sudden-onset hearing loss, it may be difficult initially since the ears and brain have little time to adapt.
Tympanic Membrane Injury
Physical trauma has a wide range of different ways it can impact you, and one of those possibilities is by affecting the ears.
Specifically, the tympanic membrane can be vulnerable to damage and can cause hearing loss. The tympanic membrane, also known as the eardrum, is a thin membrane that divides the outer ear from the middle ear. The membrane is responsible for conducting soundwaves in a manner that oscillates the bones of the middle ear for the cochlea to sense sounds.
Certain activities can increase your risk of eardrum perforation, such as flying when congested, deep water diving, being near extreme sound levels, or other activities that involve a large pressure difference.
Eardrum injuries can occur to both ears, but often it only occurs on one side. Tympanic membrane injury to one ear can result in unilateral conductive hearing loss. If your hearing loss in one ear is sudden and abrupt following a particular activity, you should go to your doctor to rule out any more serious underlying conditions. In some cases, infection and skin can grow behind the eardrum and cause a benign skin tumor called a cholesteatoma. Cholesteatomas are slow-growing, and the skin can release enzymes that can damage the middle and inner ear structures. Hearing loss can result, but hearing can also be improved with surgery in most cases. There are artificial bones that can be used to replicate ones lost from the damage.
Treatments for Tympanic Membrane Injury
While an eardrum tear sounds terrible, in reality, tympanic membrane injuries can heal independently in most cases. The recovery for a ruptured tympanic membrane injury can vary, but in most cases, it can heal in roughly three months.
If you suspect an eardrum rupture, you should seek medical attention to rule out other potential problems and to ensure that you get correct information and medications to prevent the potential for infection. An ENT specialist must determine if the eardrum rupture is only that, and there is not something more going on, such as a cholesteatoma.
Ear drops may be prescribed to avoid infection, and you may be advised to wear earplugs while swimming or showering. Additionally, some ruptures may require surgery, and at your visit, a trained medical professional will be able to guide you through your recovery and the best course of action for you.
How Is Asymmetrical Hearing Loss Diagnosed?
While traditional bilateral hearing loss may be easily identified, single-sided hearing loss can be a little trickier for people to seek help. Unlike those with bilateral hearing loss, those with one-sided hearing loss typically retain the ability to hear others but can experience unique signs and symptoms over a traditional bilateral hearing loss.
Symptoms of Asymmetrical Hearing Loss
A unique presentation of one-sided hearing loss is known as the head shadow effect. Essentially when a sound is emanating from the side of the affected ear, an individual is unlikely to hear it since the functional ear is not receiving those sound signals. In this way, the head acts as a block to the sound and casts a symbolic shadow that doesn’t allow you to perceive sound with your good ear.
To hear the sound, an individual with unilateral hearing loss typically needs to turn their head so that their non-affected ear is pointed at whoever is speaking.
People who find themselves frequently turning their head during conversations to hear better may want to get a hearing test to ensure their auditory acuity is fully intact, as it can indicate the beginning of hearing loss.
Additional symptoms of unilateral hearing loss include dizziness, a more challenging time hearing people in a noisy environment, difficulty hearing whispers, and more. Getting tested earlier rather than later can allow you to regain your quality of life faster.
Diagnosing Asymmetrical Hearing Loss
The best way to identify unilateral hearing loss is to conduct a pure sound test. A pure sound test is conducted during a standard hearing test, and it aims to see at what relative volume you can hear different pitches.
The test involves wearing isolating headphones and a device where an audiologist can manipulate pitch, intensity, and the ear sounds emitted from the headphones. The audiologist will play a tone and ask the patient to raise the hand on the corresponding side to which it was heard. If the sound is played and not heard, the audiologist will try again at a slightly higher volume.
The output is called an audiogram, and it shows a graph of how well you are able to hear each pitch. The graph shows how both ears performed, and if one ear is significantly worse, it indicates unilateral hearing loss.
Treatment for Asymmetrical Hearing Loss
If you are experiencing hearing loss or deafness in one ear, some options that could help include cochlear implants, oral steroids or injections, hearing aids, and the use of sign language.
In summary, hearing loss in one ear can have many different underlying causes ranging from physical injury to biological ailments. While the three causes outlined above can cause single-sided hearing loss, there are several other potential causes. If you experience symptoms of single-sided hearing loss, you should schedule an appointment with your audiologist to get12 tested and can find the best treatment option for you.