All About Unilateral Hearing Loss: Causes of Hearing Loss in One Ear, Diagnosis and Treatment

Unilateral hearing loss refers to the partial or complete loss of hearing in one ear, while the other ear retains normal hearing ability. It can occur due to various factors, including infections, head trauma, exposure to loud noises and tumors.

The onset of unilateral hearing loss can be either sudden or gradual, depending on the underlying cause. Moreover, the severity of the condition can vary from person to person – it can range anywhere from mild to profound hearing loss.

In the United States, an estimated 7% of adults and 0.1% of children suffer from unilateral hearing loss. Read on as we share more about this condition, including its signs, causes, treatment and prevention methods.

How Unilateral Hearing Loss Affects Your Life

Unilateral hearing loss can have several impacts on your hearing abilities, auditory experience and overall well-being. It’s important to note that the impact of this condition can vary from person to person, depending on the severity of the hearing loss.

Here are some ways in which unilateral hearing loss can affect your hearing:

Sound localization

One of the primary challenges with unilateral hearing loss is difficulty in accurately localizing sounds. The ability to determine the direction from which a sound is coming is primarily dependent on having 2 functioning ears.

With only 1 ear providing auditory input, it becomes challenging to accurately identify the source of sounds, which can affect your spatial awareness.

Speech understanding in noisy or challenging environments

Unilateral hearing loss can significantly impact speech understanding, especially in noisy or challenging environments.

Background noise can make it difficult for you to separate the speech you want to hear from competing sounds. This is especially so if the noise is coming from the direction of your good ear, while the speech signal is coming from the direction of your poorer ear. This can lead to decreased speech clarity and comprehension in social gatherings, classrooms, or other noisy settings.

Furthermore, conversations in a group setting can be problematic, as it may be hard to focus on the speaker and distinguish their voice from others.

Loudness of sounds

When a sound is detected by both ears, the brain perceives it to be louder compared to when it is only heard through one ear, even if the sound is at the same decibel level. This is because the brain receives signals from the nerves in both ears and utilizes this combined information to interpret and process sounds.

Thus, if you have unilateral hearing loss, you may perceive sounds to be softer than they actually are.

Psychological and social impact

Aside from your hearing, unilateral hearing loss can have psychological and social consequences. It may lead to feelings of isolation, frustration, and decreased self-confidence, particularly in situations where communication is challenging. Increased social isolation may contribute to the risk of dementia.

It can also affect interpersonal relationships, as individuals with unilateral hearing loss may struggle to fully engage in conversations or may avoid certain social situations altogether.

Listening fatigue

If you have unilateral hearing loss, you may find it difficult to multitask. This is because hearing loss places an additional cognitive burden on the brain, resulting in listening fatigue. When there is background noise present, the brain takes more time to concentrate on its current tasks.

Signs of Hearing Loss in One Ear

Signs that you may have hearing loss in one ear include (but are not limited to):

• Tinnitus in one ear
• Frequently needing others to repeat what they said
• Showing a preference for one ear during phone calls or conversations
• Increasing the volume of the television
• Challenges in understanding conversations, especially in noisy environments

Causes of Hearing Loss in One Ear

Unilateral hearing loss can be caused by various factors including:

Blockage of the ear canal

A buildup of earwax in one ear can cause your ear canal to be blocked. This can, in turn, result in hearing loss.

Acoustic trauma

Prolonged exposure to loud noises or a single extremely loud noise can damage the structures responsible for hearing in one ear, resulting in noise-induced hearing loss.

Head trauma

Trauma to the head, such as a severe blow or skull fracture, can cause damage to the ear structures or nerves, resulting in hearing loss in one ear.

Congenital factors

Some individuals are born with hearing loss in one ear due to genetic or developmental abnormalities affecting the inner ear or auditory nerve.

Infections

Severe infections, such as meningitis or labyrinthitis, can damage the inner ear structures and nerves, leading to unilateral hearing loss. Ear infections, such as otitis media or otitis externa, can also result in unilateral hearing loss.

Tumors

The presence of tumors, such as acoustic neuroma or other types of growths near the ear or auditory nerve, can cause hearing loss in one ear.

Autoimmune disorders

Certain autoimmune conditions, like Ménière's disease or autoimmune inner ear disease, can cause inflammation and damage to the inner ear structures, leading to hearing loss.

Age-related factors

Although age-related hearing loss usually affects both ears, it can manifest primarily in one ear, resulting in unilateral hearing loss.

Diagnosing Hearing Loss in One Ear

Diagnosing unilateral hearing loss typically involves a comprehensive evaluation conducted by an audiologist or an ear, nose, and throat (ENT) specialist. Aside from a physical examination of your ear, different types of hearing tests may be conducted, including:

• Pure Tone Audiometry (PTA)
• Speech audiometry
• Tympanometry
• Otoacoustic Emissions (OAE) testing
• Imaging studies

Early detection and intervention play a crucial role in managing hearing loss effectively and preventing further damage to your ears. If you suspect that you have hearing loss in one ear, you’re recommended to take a hearing test with an audiologist or ENT doctor as soon as possible.

Treatment for Hearing Loss in One Ear

Unilateral hearing loss is generally treated using CROS or bone-anchored hearing aids. Your audiologist or ENT doctor will advise you on the type that’s most suitable for your condition.

CROS hearing aids

CROS hearing aids are often recommended for single-sided deafness. However, they may also be recommended for unilateral hearing loss, depending on the situation.

The CROS system consists of 2 components:

• A microphone that picks up sounds from the non-hearing ear
• A transmitter that wirelessly sends these sounds to a hearing aid worn on the better-hearing ear

The hearing aid on the better ear receives the signals from the non-hearing side and amplifies them, allowing the person to hear sounds coming from their non-hearing side through their functional ear.

Bone-anchored hearing aids

Bone-anchored hearing aids (BAHAs) are a type of hearing device that bypasses the outer and middle ear and directly stimulates the inner ear through bone conduction.

When wearing a BAHA, the sound processor picks up sounds and converts them into vibrations or electrical signals. These signals are then sent to the abutment, which transmits the vibrations through the skull bone to the inner ear. The inner ear receives these vibrations, bypassing any issues with the outer or middle ear, and converts them into electrical signals that are interpreted by the brain as sound.

BAHAs require a surgical procedure for the placement of the abutment and implant. The candidacy for a BAHA is determined by an assessment from an audiologist or an ENT specialist.

Preventing Hearing Loss in One Ear

Prevention is always better than cure! Here are some ways you can protect your ears and prevent hearing loss:

Turn down the volume

When using headphones or earbuds, keep the volume at a safe and comfortable level. As a general guideline, if someone standing near you can hear the sound from your headphones, it's too loud.

Maintain ear hygiene

Keep your ears clean and dry to prevent infections. Avoid digging your ears and inserting objects like cotton swabs or hairpins into your ear canal, as they can cause damage or push earwax deeper.

Additionally, use earplugs or custom-fitted swim molds to protect your ears when swimming or participating in water activities, especially if you’re prone to ear infections or have had ear surgery.

Protect your ears from loud noise

Avoid prolonged exposure to loud noises or use proper hearing protection such as earplugs or earmuffs when you are in noisy environments, such as concerts, sporting events, or construction sites.

Get regular hearing check-ups

Scheduling regular hearing evaluations with an audiologist allows you to monitor your hearing health and detect any signs of hearing loss early on.

FAQs About Hearing Loss in One Ear

What is the difference between unilateral hearing loss and single-sided deafness?

Single-sided deafness (SSD) is a form of unilateral hearing loss. However, it’s more severe.

While unilateral hearing loss refers to significant hearing impairment in one ear and normal or near-normal hearing in the other ear, SSD implies a complete or near-complete hearing loss in one ear, where no functional hearing remains.

Both conditions can have similar consequences, such as difficulties in communication, sound localization, and understanding speech in challenging listening environments. However, the impact may be more pronounced in SSD due to the absence of any hearing perception in the affected ear.

What is the difference between unilateral and bilateral hearing loss?

Unilateral hearing loss refers to hearing loss in only one ear. On the other hand, bilateral hearing loss refers to hearing impairment in both ears.

Bilateral hearing loss can be symmetrical, where both ears have similar degrees of hearing loss. It can also be asymmetrical, where one ear has more significant hearing loss than the other.

As bilateral hearing loss affects both ears, the impact is often more significant for such individuals. They tend to have more difficulties with speech understanding and communication.