Hearing loss in one ear: how to recognise and treat it
Hearing loss in one ear, or unilateral hearing loss, is more common than many people realise. It can range from mild difficulty hearing in noisy environments to complete unilateral deafness, and its impact on daily life, communication and mental health can be significant. Understanding the causes, symptoms and available treatments is the first step towards managing it effectively.
What is unilateral hearing loss?
Unilateral hearing loss is a hearing impairment affecting one ear only, while the other ear maintains normal or near-normal hearing. It can be present from birth - in which case it is congenital - or develop later in life as a result of illness, injury or noise exposure. The degree of loss can vary from mild to profound, and in some cases it may come on suddenly.
Research suggests unilateral hearing loss can be more disabling than bilateral hearing loss for specific tasks, particularly sound localisation and understanding speech in noisy environments. Unlike bilateral loss, where both ears provide some input, unilateral loss removes the brain's ability to process binaural cues, making it harder to identify where sounds are coming from.
Symptoms of unilateral hearing loss
Because one ear continues to function normally, unilateral hearing loss is often overlooked or mistaken for inattention. Common signs include:
- Difficulty understanding speech in noisy environments
- Inability to locate the direction of sounds
- Frequently asking people to repeat themselves
- Turning one side of the head towards speakers
- Fatigue from straining to hear
- Tinnitus (ringing or buzzing) in the affected ear
- A feeling of fullness or blockage in one ear
- Sudden loss of hearing in one ear - which should always be treated as a medical emergency.
In children, symptoms may present as delayed language development, difficulty following instructions in class, or poor school performance despite normal intelligence.
Unilateral hearing loss: Causes
The following causes are the most common ones for hearing loss in one ear:
Infections and viruses
Head trauma
Tumors
Otosclerosis
Ménière's disease
Noise exposure
Auditory nerve abnormality
How is unilateral hearing loss diagnosed?
Diagnosis typically begins with a hearing test (audiogram) conducted by an audiologist. This maps the hearing thresholds of each ear separately and identifies the degree and type of hearing loss. Additional tests may include:
- Tympanometry: assesses the function of the middle ear and eardrum
- Auditory brainstem response (ABR): measures how the auditory nerve and brainstem respond to sound, useful when behavioural testing is not possible (e.g. in infants)
- MRI or CT scan: used to identify structural causes such as tumours or cochlear nerve abnormality
- Blood tests: to rule out infectious or autoimmune causes
If you notice sudden hearing loss in one ear, seek medical attention within 24–48 hours: prompt treatment significantly improves the chances of recovery.
Unilateral hearing loss: Treatment
Treatment depends on the underlying cause and the degree of hearing loss.
In some cases, addressing the cause, such as removing earwax, treating an infection or managing Ménière's disease, can resolve or improve hearing.
When hearing loss is permanent, the following options are available:
- CROS hearing aid: designed specifically for single-sided deafness (SSD), a microphone placed at the impaired ear routes sound to a hearing aid in the functioning ear
- BiCROS hearing aid: a variation for asymmetrical hearing loss, where both ears have some degree of impairment but one is significantly better than the other
- Bone-anchored hearing aid (BAHA): a sound processor attached to a small titanium implant behind the ear transmits sound via bone conduction to the functioning inner ear (studies show significant improvement in speech understanding in noise)
- Cochlear implant: for severe to profound hearing loss unresponsive to hearing aids; the MED-EL Synchrony system was approved specifically for single-sided deafness and helps with sound localisation and hearing in noisy environments
- Corticosteroids: for sudden sensorineural hearing loss, high-dose corticosteroids (oral or injected) administered promptly may help recover some or all of the lost hearing.
44%
of people with unilateral hearing loss currently used a hearing device
How does unilateral hearing loss affect daily life?
Unilateral hearing loss can have a significant impact on everyday life, even when the other ear functions normally. The most common difficulties include:
- Difficulty hearing in noisy environments: without input from both ears, the brain struggles to separate speech from background noise — making conversations in restaurants, meetings or crowded spaces particularly challenging
- Poor sound localisation: identifying where a sound is coming from relies on the brain comparing signals from both ears. With only one functioning ear, this ability is significantly reduced
- Listening fatigue: the effort required to compensate for the loss in one ear can cause considerable mental tiredness, particularly after long conversations or in demanding acoustic environments
- Psychological impact: difficulty communicating can lead to anxiety, reduced self-confidence and social withdrawal
- Workplace challenges: fear of being judged or misunderstood can lead people to hide their hearing loss, which may create additional stress
People who have had unilateral hearing loss since birth tend to develop stronger coping strategies and generally report less impact on quality of life than those who acquire the condition later in life.
FAQs about unilateral hearing loss
Is unilateral hearing loss common?
Can unilateral hearing loss affect the brain?
Can unilateral hearing loss be treated?
