What Is Unilateral Hearing Loss (Single-Sided Deafness)

Do you notice that you hear better with one ear compared to the other? Do you sit closer to someone so you can use your “better ear”? Or perhaps you always use the same ear for phone calls without realising it. If this sounds familiar, you may be experiencing unilateral hearing loss — also known as single-sided deafness (SSD). This condition is more common and often more troublesome than people realise.

How Common Is Unilateral Hearing Loss?

Many people don’t realise they have unilateral hearing loss because they rely heavily on their stronger ear. However, research shows that unilateral hearing loss affects both adults and children worldwide.

Global Adult Statistics

• A Harvard Medical School study found that 7.2% of adults have some form of unilateral hearing loss. (Shargorodsky et al., PubMed)
• More severe SSD affects 0.11% to 0.14% of adults, or about 1–1.4 per 1,000. (University of Minnesota, PubMed)
• A South Korean national health survey found 5.55% of adults have unilateral hearing loss. (Kyung Hee University Hospital, PLOS One)

Global Child Statistics

• Between 0.3 to 1 per 1,000 newborns are born with unilateral hearing loss. (AAO-HNS Bulletin)
• 20%–50% of congenital hearing loss in children affects only one ear. (NIH / NLM)
• In a study of 52,878 children, 0.36% were diagnosed with SSD. (Wayne State University School of Medicine)

What Causes Unilateral Hearing Loss?

Unilateral hearing loss refers to reduced or no hearing in one ear, ranging from mild to profound. It may be caused by:

• Head trauma or injury
• Physical damage to the ear
• Pressure on the hearing nerve (e.g., acoustic neuroma)
• Inner ear infections (viral or bacterial)
• Meniere’s disease
• Congenital factors
• Sudden unexplained hearing loss

Some people develop UHL gradually, while others experience it suddenly.

Why Two-Ear Hearing Matters

Our hearing system is designed to receive sound input from both ears. When one ear is not functioning properly, everyday listening becomes more challenging. People with single-sided deafness often experience:

• Difficulty locating sound direction
• Trouble hearing when someone speaks from their weaker side
• Missing parts of conversations
• Difficulty hearing in noisy environments

With two healthy ears, we benefit from:

• Better conversation flow
• Better speech understanding
• More accurate sound localisation
• Improved hearing in background noise

You do not have to live with unilateral hearing loss. With proper help, you can perform well in work meetings, busy restaurants, classrooms, or family gatherings.

Treatment Options for Unilateral Hearing Loss (Non-Surgical)

1. Conventional Hearing Aids

A conventional hearing aid can restore hearing in the weaker ear and help improve localisation. Many people with mild to moderately severe UHL experience significant improvement. Brands such as Phonak, ReSound, and Signia offer suitable options.

2. CROS and Bi-CROS Hearing Systems

For severe or profound UHL — when a hearing aid cannot provide enough benefit — a CROS or Bi-CROS system may be recommended.

How it works:

• A microphone is placed on the poorer ear.
• It sends sound wirelessly to the hearing aid worn on the better ear.
• This helps the wearer hear sounds coming from their weaker side.

Phonak, ReSound, and Signia offer excellent CROS and Bi-CROS systems. You can visit SOUNDLIFE for a free trial.

3. Bone Conduction Hearing Aids (BAHA)

Bone conduction hearing aids are suitable for individuals with:

• Atresia (small or absent ear canal)
• Microtia or anotia
• Chronic ear discharge (CSOM)
• Single-sided deafness

These devices send sound vibrations through the bone directly to the inner ear. Options include MedEl ADHEAR and Cochlear BAHA Softband.

4. Phonak Roger System

The Phonak Roger system is a wireless microphone that helps SSD users hear speech clearly in noisy environments. It improves the speech-to-noise ratio by about 10 dB, making communication easier in restaurants, classrooms, meetings, and social events.

Surgical Treatment Options for Unilateral Hearing Loss

Cochlear Implant

When hearing aids are no longer helpful, a cochlear implant may provide a more effective long-term solution. Unlike hearing aids, cochlear implants stimulate the hearing nerve directly through electronic signals.

The system includes:

• An external sound processor
• An internal implant placed inside the cochlea

Bone-Anchored Hearing Implant (BAHA Implant)

This system is suitable for conductive, mixed, and single-sided deafness. It offers strong and direct sound transmission through a titanium implant behind the ear, connected to an external processor.