What is unilateral hearing loss?
Unilateral hearing loss is hearing loss in one ear. It’s also called single-sided deafness or unilateral conductive hearing loss.
If you have unilateral hearing loss, you can hear normally in the other ear, but you may have trouble understanding speech if there’s background noise or if the person speaking to you is on your side with his or her mouth close to your ear.
Unilateral hearing loss can be caused by:
- Acoustic neuroma — a benign tumor that grows from the nerve between your inner ear and brainstem (see Acoustic Neuroma)
- Aging (presbycusis) — a gradual loss of hearing that occurs as part of the normal aging process (see Presbycusis)
- Damage to the inner ear caused by infections (such as meningitis), trauma or loud noises (acute acoustic trauma)
What is single-sided deafness?
Single-sided deafness (SSD) is a condition in which one ear fails to hear sounds properly. This can be caused by damage to the inner ear or by problems with the nerve that carries sound from the ear to the brain.
SSD makes it difficult for you to understand speech in noisy places and may cause you to miss important sounds in your environment.
SSD can occur as a result of middle or inner ear damage or hearing loss, or damage to the nerve connecting the ear to the brain.
The symptoms of single-sided deafness include:
- Trouble understanding speech when there’s background noise, such as at parties, restaurants, etc., even if you can hear well when there’s no background noise
- Losing your place when listening to someone speaking to you while they’re moving around — this is called “lateralization” because it occurs only on one side of your head
- Having trouble hearing words that begin with certain sounds — such as “th” as in “thing,” “sh” as in “shoe,” or “b” as in “bee”; these are called consonants
How common is unilateral hearing loss?
Unilateral hearing loss is a common occurrence. It is estimated that between 20 and 30 percent of all Americans have some degree of unilateral hearing loss. In most cases, it is due to noise exposure or genetics.
Noise Exposure
Unilateral hearing loss can be caused by long-term exposure to excessive noise levels. Most commonly, this type of hearing loss affects your high tones because they are the first to be damaged when exposed to loud noises. If you work in a noisy environment, such as an auto shop or construction site, you may be at risk for unilateral hearing loss.
Genetics
Genetics may also play a role in unilateral hearing loss. If one parent has a hearing impairment, it increases the likelihood that their child will also have some form of hearing loss. Some believe that there may be a connection between certain genes and unilateral hearing loss, although this theory has not been proven yet.
What should I do if I think I have unilateral hearing loss or single-sided deafness?
If you think you have unilateral hearing loss, or single-sided deafness, you should seek treatment from an ear, nose and throat (ENT) specialist.
A doctor will do a thorough examination of your ear canal and eardrum. This may include:
- Listening to sounds in each ear separately with a small device called a hearing aid
- Looking into your ear with a microscope
- Testing the nerves that control balance
- Testing the muscles of your face by touching them with a tiny puff of air or water
Why is it important to manage unilateral hearing loss or single-sided deafness?
There are many reasons why it is important to manage unilateral hearing loss or single-sided deafness.
The first reason is that you may be unable to hear sounds coming from one side. This can make it difficult to understand speech or even hear music. You might need to keep asking people to repeat what they’ve said, or ask them to speak more loudly. You might also have trouble understanding the person sitting next to you in the car when a siren goes off on another side of the road.
The second reason is that untreated unilateral hearing loss could have a negative impact on your speech and language skills. This can happen if you don’t know how to compensate for one-sided deafness using your other ear and/or lipreading skills. It can also happen if you don’t know how to compensate for one-sided deafness using visual cues such as facial expressions and body language when communicating with others. If this happens, then your speech and language development may be delayed or even affected permanently.
How is unilateral hearing loss managed?
There are several treatment options for people who suffer from unilateral hearing loss. You may want to consider the following:
Hearing aids: These devices amplify sound waves so that you can hear better. They come in different styles and shapes depending on how much hearing loss you have and where it occurs in your ear. Some people choose to use both hearing aids at once, while others may choose only one device for their left or right ear.
Cochlear implants: These surgically implanted devices bypass damaged areas of the inner ear and stimulate nerves directly with electrical impulses transmitted from the device’s microphone to the implant’s internal receiver. The implant then sends signals through electrodes attached behind the ear into the brainstem — which relays them to the auditory cortex where they are processed as sounds by neurons that respond.
Cause of unilateral hearing loss
The cause of unilateral hearing loss (UHL) is not always clear. It can be caused by any of the following:
Common infectious diseases, such as meningitis and mumps
Acute otitis media (AOM), or middle ear infection, which is one of the most common childhood diseases
Surgery to remove wax from the ear canal or a foreign object from the eardrum. A ruptured ear drum can also cause UHL.
Infections such as meningitis and mumps can cause UHL if they affect both ears at once. Otitis media (inner ear infection) often causes UHL when it affects only one ear, but rarely causes UHL when both ears are affected at once. Some foreign objects may enter an ear canal and cause UHL when they move back and forth against the eardrum.