People with hearing loss typically have some degree of hearing loss in each ear – it’s less common to have hearing loss in just one ear. But unilateral hearing loss (UHL), which is also known as single-sided deafness, occurs when an individual has normal hearing in one ear and experiences mild to severe or profound hearing loss in the other ear. Children can be born with UHL, but it can also happen to adults later in life. Statistics show that one of every 10,000 children is born with UHL, while it’s estimated that 60,000 U.S. adults each year acquire UHL.
Unilateral hearing loss can have many causes, including:
- Genetic hearing loss
- Head injury
- Exposure on one side to loud impulse noise, like a fired gun or an explosion
- A viral infection
- An inner, outer or middle ear abnormality
- Meniere’s disease
- The surgical removal of a brain tumor or tumor on the auditory nerve
Sometimes, however, it is not known what has caused UHL.
Many people live with untreated unilateral hearing loss because they feel that as long as they can hear well in one ear, everything is fine. However, UHL can cause difficulties in determining from which side a sound is coming and separating speech from background noise.
Just as with bilateral hearing loss, individuals can benefit from many different hearing loss solutions, including aural rehabilitation, improved tactics for listening and speech and assistive listening devices, though tactics depend on the degree of UHL a person has.
There are also hearing devices that can help balance the auditory system by routing sounds that come in through one ear to the other. These include bone-anchored hearing aids (BAHA devices) and contralateral routing of signal hearing aids (CROS).