What is a unilateral hearing loss?
A unilateral hearing loss is a hearing loss in one ear, as opposed to a bilateral hearing loss, where the hearing loss occurs in both ears. A unilateral hearing loss can range from mild to severe or profound and often affects quality of life.
A unilateral hearing loss may also be called a one-sided hearing loss or a single-sided hearing loss.
If a unilateral hearing loss is severe or profound, it is often called single-sided deafness (SSD), as there is practically no hearing left. Single-sided deafness is defined as a hearing loss with normal or near to normal hearing in one ear (“the good ear”) and severe to profound hearing loss in the other. If the unilateral hearing loss is severe or profound, the person affected more or less only hears with one ear (monoaural hearing). Single-sided deafness may also be called unilateral deafness.
A unilateral hearing loss can occur in both in adults and children. A unilateral hearing loss is quite common. Nobody knows the number of people who live with a unilateral hearing loss, but it is estimated that in the US alone 60,000 people have a unilateral hearing loss.
Signs and symptoms of unilateral hearing loss
What are the signs and symptoms of a unilateral hearing loss? People with a unilateral hearing loss often have problems localising sound (to hear where the sounds come from) and have problems with understanding speech in noise or noisy surroundings. If you have problems hearing people talking to you from one side, you may also have a unilateral hearing loss.
Causes of unilateral hearing loss
What causes unilateral hearing loss? A unilateral hearing loss can occur as a result of many causes.
- It can be inherited (as other types of genetic hearing loss).
- It can occur as a result of a trauma or injury to the head.
- An acoustic neuroma often results in a unilateral hearing loss.
- If can be a result of viral or bacterial infections.
A unilateral hearing loss can also be caused by maternal illnesses, microtia, Ménière’s disease and mastoiditis.
Treatment of unilateral hearing loss
Treatment of a unilateral hearing loss includes both surgical and non-surgical options. A unilateral hearing loss is normally treated with hearing aids or hearing implants such as bone conduction devices. A cochlear implant can also be used as treatment for a unilateral severe sensorineural hearing loss, if the cochlea in the inner ear is intact. The treatment depends on the severity and type of the hearing loss.
If there is hearing left in the affected ear, a unilateral hearing loss can often be treated with amplification by using a normal hearing aid (hearing aids for single sided deafness).
But if there is no hearing or practically no hearing left, a special type of hearing aid called a CROS hearing aid is often used. A CROS hearing aid sends the sound from the affected ear to the normal hearing ear. Today, this is mostly done by wireless transmission, but it can also be sent to the hearing ear by a wire behind the neck. A special type of CROS hearing aid is a BiCROS hearing aid. A BiCROS aid is used when there is also a hearing loss in the better (hearing) ear.
Hearing implants such as bone conduction devices are used to treat some types of severe or profound unilateral hearing loss (single-sided deafness) by sending sound from the non-hearing side to the hearing ear on the other side of the head.
Unilateral hearing loss in children
Children may also experience a unilateral hearing loss. 1 out of 1000 children are born with a unilateral hearing loss and around 3% of all school children have some degree of unilateral hearing loss. The causes are often genetic, from maternal illnesses or caused by infections or damage to the ear.
A unilateral hearing loss in children affects hearing and may influence both speech recognition and language development as well as the ability to localise sounds.
The age of onset depends on the cause of the unilateral hearing loss.
Unilateral hearing loss in children is normally treated with hearing aids or hearing implants such as bone conduction devices.
As with other hearing losses in children, it is important to be aware of and address the hearing loss in both the kindergarten and at school including teachers, the other pupils and the other parents.
Sudden unilateral hearing loss
A hearing loss in one ear can also occur suddenly. Then it is a sudden unilateral hearing loss, a type of a sudden hearing loss. If you experience a sudden hearing loss in one ear, you should seek medical help as soon as possible. The quicker the treatment, the better are the chances of recovery.
Unilateral hearing loss and tinnitus
People who have a unilateral hearing loss may also experience tinnitus. The tinnitus can be in the affected ear or in both ears. There is not always a connection between the hearing loss and tinnitus.
What to do?
What should I do if I think I have a unilateral hearing loss? If you think that you have a unilateral hearing loss, you should contact a hearing professional to get a hearing test. If you experience a sudden unilateral hearing loss you must seek medical treatment as soon as possible.