Living with Single-Sided Deafness

Hearing loss that affects only one ear is often underestimated – by patients and those around them alike. Known as single-sided deafness, this condition can affect hearing ability, communication and quality of life in ways that are not always visible. Understanding the causes and treatment options can help people regain confidence and reconnect with the world around them.

What is single-sided deafness?

Single-sided deafness (SSD) refers to significant or complete hearing loss in one ear, while hearing in the other ear is normal or near-normal. For many years, SSD was largely overlooked – most people were simply told that no intervention was needed because the other ear was functioning. In reality, hearing with two ears (binaural hearing) plays a crucial role in how we understand speech, locate sounds and feel secure in our surroundings.

Why hearing with two ears matters

Hearing is not simply about volume. Our brains rely on input from both ears to:

• Understand speech in noisy environments – such as in restaurants or meetings. Two ears help the brain separate speech from background noise, making conversations easier to follow.
• Hear sounds from both sides clearly – when someone speaks from the affected side, their voice may be muffled or lost before reaching the hearing ear.
• Identify where sounds are coming from – including traffic, phones, alarms or someone calling your name.
• Listen with less effort and fatigue – balanced hearing reduces listening strain and helps prevent mental tiredness throughout the day.
• Maintain balance and spatial awareness – hearing works together with the balance system to support orientation and stability.

When one ear stops working, the brain loses important timing and directional cues. This can make everyday listening situations unexpectedly tiring and frustrating.

Common symptoms of hearing loss in one ear

People with SSD often report challenges that go beyond simply 'not hearing well':

• Difficulty following conversations in noisy environments
• Trouble identifying who is speaking or where sound comes from
• Needing to constantly reposition to hear better
• Increased listening effort and fatigue – the more noise there is, the harder the brain has to work
• Ringing in the affected ear (tinnitus)
• Loss of confidence in group settings, such as work meetings or family dinners
• Social withdrawal, frustration or isolation
• Feeling vulnerable or anxious in crowded environments, such as busy streets
• In children, SSD may present additional challenges with language development, learning and classroom listening

These symptoms can be subtle at first, particularly when hearing loss develops gradually.

What causes single-sided deafness?

Some people are born with SSD, while others develop it later in life due to a wide range of causes. Onset may be sudden or gradual.

Sudden sensorineural hearing loss

A rapid loss of hearing in one ear, often occurring over hours or days. It may feel like a blocked or muffled sensation, or you may notice you cannot hear through a phone or headphones on one side. This is a medical emergency – seek urgent assessment by an ENT specialist, GP or at an emergency department.

Viral or bacterial infections

Infections such as mumps, measles or meningitis can damage the inner ear.

Acoustic neuroma (vestibular schwannoma)

A benign tumour affecting the hearing and balance nerve, typically causing progressive hearing loss in one ear.

Inner ear disorders

Conditions such as Ménière's disease may initially affect one ear.

Head injury or trauma

Damage to the inner ear or auditory nerve following an accident.

Congenital causes

Some people are born without a functioning inner ear or auditory nerve on one side.

Noise exposure

Sudden loud noise or prolonged asymmetric exposure can sometimes affect one ear more than the other.

How is single-sided deafness diagnosed?

Diagnosis begins with a comprehensive hearing assessment, including:

• Pure-tone audiometry to measure hearing levels
• Speech testing to assess clarity and understanding
• Tympanometry to evaluate middle ear function

Depending on the findings, further tests such as an MRI scan may be recommended – particularly when hearing loss is unexplained or progressive.

Early diagnosis is important, especially in cases of sudden hearing loss, where timely treatment (ideally within 72 hours) can significantly improve outcomes.

Treatment options for hearing loss in one ear

Treatment depends on the cause, severity and duration of hearing loss, as well as the individual's lifestyle and needs.

Treating the underlying cause

Sudden hearing loss is commonly treated with steroids, taken orally or delivered directly into the ear (intratympanic injection). Hyperbaric oxygen may also be an option. Hearing may return fully, partially or not at all, depending on the severity and cause.

Hearing aids for the affected ear

If there is usable hearing remaining, a modern hearing aid may help amplify sound and improve clarity.

CROS and BiCROS hearing systems

For people with little or no hearing in one ear, CROS (Contralateral Routing of Signals) systems pick up sound from the deaf side and transmit it to the hearing ear. These devices can:

• Improve awareness of sounds from the affected side
• Reduce the need to always position the good ear towards speakers

However, they do not restore true two-ear hearing or sound localisation.

Bone-conduction hearing devices

Bone-conduction devices transmit sound vibrations through the skull to the better-hearing ear. Like CROS systems, they reroute sound from the deaf side, but they do not restore true two-ear hearing.

Cochlear implants for single-sided deafness

Cochlear implants are increasingly being used for SSD in selected patients. Unlike other devices, a cochlear implant stimulates the deaf ear directly, allowing the brain to receive input from both sides again. Potential benefits include:

• Improved speech understanding in noise
• Better sound localisation
• Ability to hear from both sides
• Reduction in tinnitus in many patients
• Improved listening comfort and quality of life

Not everyone with SSD is suitable for a cochlear implant, and careful assessment is required.

What about tinnitus in one ear?

Tinnitus is common in single-sided deafness and can be particularly distressing when only one ear is affected. Restoring sound input – whether through hearing devices or cochlear implants – can significantly reduce tinnitus perception in many patients.

When should you see a specialist?

Seek specialist assessment if you experience:

• Sudden hearing loss or a blocked sensation in one ear
• Persistent or worsening hearing asymmetry
• Tinnitus in one ear
• Dizziness or balance symptoms alongside hearing loss
• Difficulty coping despite having 'normal' hearing in one ear

Early evaluation allows for a broader range of treatment options and better outcomes.

A personalised approach to care

There is no single 'best' solution for single-sided deafness. Management should be individualised, taking into account:

• Cause and duration of hearing loss
• Age and lifestyle needs
• Work and social listening demands
• Presence of tinnitus or balance symptoms

A multidisciplinary team involving ENT specialists and audiologists is key to achieving the best outcomes.