Most of the time, hearing loss affects both ears and to the same degree. But sometimes, the level of hearing loss can differ from ear to ear, and in some cases, one ear can have normal hearing while the other ear has severe-to-profound hearing loss. This is the case with single-sided deafness, which is also called unilateral hearing loss.
So what causes single-sided deafness?
There are many causes of single-sided deafness such as:
- Sudden sensorineural hearing loss
- Genetic factors
- Certain syndromes
- Physical trauma (head injury)
- Acoustic trauma (exposure to an extremely loud sound such as an explosion or gunshot)
- Ménière’s disease
- Tumours on the nerve of hearing and/or in the brain
- Infectious diseases much as meningitis, measles and mumps
People with single-sided deafness often experience the following:
- Difficulty following conversations in noisy environments such as a busy restaurant
- Difficulty locating where sounds are coming from (localization)
- Increased listening effort (straining to hear)
What can be done for single-sided deafness?
Are there hearing aids for single-sided deafness? We have two ears for a reason. Our brain needs to hear from both sides to provide the best listening experience and to be fully aware of our surroundings. It's important to be able to hear a car’s horn when crossing a busy street, for example. It's also important to be able to detect the direction sound is coming from. While single-sided deafness is almost always permanent, and the hearing loss in the “bad ear” cannot be restored, there is help for single-sided deafness.
Here are some treatment options:
Sometimes, a traditional hearing aid is the best solution for single-sided deafness when one ear has normal hearing and the other has severe-to-profound hearing loss. If you have hearing loss in both ears, but one side is worse than the other, your audiologist may recommend a hearing aid for each ear.
If your audiologist tells you traditional hearing aids would not be suitable for you, the following options can be tried:
CROS: “Contralateral routing of signal”
A CROS system has two components: A transmitter and a receiver which both look just like regular hearing aids. A transmitter on your bad ear sends sound wirelessly to the receiver on your good ear. This allows you to hear sounds on your bad ear side so you can be more aware of your surroundings. It is also very helpful in situations where someone may be talking to you on your bad side such as when you are a passenger in a car. Many people with single-sided deafness opt for this solution as it does not require any surgery.
BiCROS: “Bilateral contralateral routing of signal”
Similar to a CROS, a BiCROS is designed for people with severe-to-profound hearing loss in one ear and a hearing loss in the other ear that is less severe. With a BiCROS system, the receiver hearing aid also amplifies sound on the better ear.
BAHA: “Bone-anchored hearing aid”
(sometimes called BAHD for bone-anchored hearing device) Unlike traditional hearing aids, a BAHA requires surgery. A sound processor located behind the ear picks up sound and sends it directly to your inner ear on your good side through something called bone conduction (for more information on the anatomy of the ear, click here). BAHAs are typically fit and adjusted in a hospital setting. Not everyone is a candidate for a BAHA and some patients decide to try a CROS or BiCROS instead to avoid having surgery.
When single-sided deafness is treated by any of the above options, patients no longer feel “closed off” on their bad side and are better able to tell where sounds are coming from and can understand conversations better in noisy environments. If you or a loved-one are experiencing single-sided deafness and are looking for a solution, call us to schedule an appointment with one of our audiologists!