What Is Bilateral Hearing Loss?

What Is Bilateral Hearing Loss?

Bilateral hearing loss means hearing loss affects both ears. It may be mild, moderate, severe, or profound, and the degree of hearing loss does not have to be the same in each ear.

Some people develop hearing loss gradually in both ears as they age or after years of loud noise exposure. Others are born with hearing loss or develop it because of infections, medications, injuries, or other medical conditions.

Bilateral hearing loss can make conversations harder to understand, especially when background noise is present. It may also affect the ability to recognize where sounds are coming from.

The key point: Bilateral describes which ears are affected. It does not identify the cause, severity, or type of hearing loss. A comprehensive hearing evaluation can help determine those details and guide treatment.

Bilateral vs. Unilateral Hearing Loss

The difference between bilateral and unilateral hearing loss is the number of ears affected.

• Bilateral hearing loss: Both ears have measurable hearing loss.
• Unilateral hearing loss: One ear has hearing loss while the other has hearing within the normal range.

Both conditions can interfere with communication and sound localization.

When both ears have hearing loss, a person may have reduced access to speech and environmental sounds from either side.

With unilateral hearing loss, the better-hearing ear may support communication, but understanding speech in noise and locating sounds can still be difficult.

Neither condition is automatically more disabling in every situation. The effects depend on hearing levels, speech understanding, listening environments, and individual circumstances.

Symmetrical vs. Asymmetrical Bilateral Hearing Loss

Bilateral hearing loss can also be described as symmetrical or asymmetrical.

Symmetrical bilateral hearing loss means the hearing thresholds in both ears are relatively similar.

Asymmetrical bilateral hearing loss means both ears have hearing loss, but one ear has substantially poorer hearing than the other at certain frequencies.

Age-related hearing loss commonly affects both ears in a relatively symmetrical pattern.

Unexplained asymmetrical hearing loss may require additional medical assessment to investigate possible underlying conditions.

What Are the Types of Bilateral Hearing Loss?

Bilateral hearing loss can involve different parts of the hearing system.

Conductive Hearing Loss

Conductive hearing loss occurs when sound cannot travel efficiently through the outer or middle ear.

Possible causes include earwax blockage, middle-ear fluid, eardrum problems, and structural abnormalities.

Some forms improve with medical or surgical treatment.

Sensorineural Hearing Loss

Sensorineural hearing loss involves the inner ear or auditory nerve.

Common contributors include aging, loud noise exposure, genetic conditions, and certain medications.

Permanent sensorineural hearing loss generally cannot be reversed with current standard treatments, although hearing aids and other interventions may improve communication.

Mixed Hearing Loss

Mixed hearing loss includes both conductive and sensorineural components.

For example, someone with permanent inner-ear hearing loss may also develop middle-ear fluid that further reduces hearing.

Treatment depends on identifying and addressing each component.

What Causes Bilateral Hearing Loss?

Hearing loss affecting both ears has several possible causes. The likely explanation depends on age, medical history, symptoms, hearing-test findings, and the timing of hearing changes.

1. Age-Related Hearing Loss

Age-related hearing loss, also called presbycusis, commonly develops gradually in both ears.

Changes in the inner ear, auditory nerve, and other parts of the hearing system can contribute.

Higher-frequency hearing is often affected earlier or more severely than lower-frequency hearing.

The National Institute on Deafness and Other Communication Disorders (NIDCD) explains that age-related hearing loss typically affects both ears and may develop so gradually that the person does not immediately notice it.

2. Loud Noise Exposure

Excessive noise can damage the sensory structures of the inner ear.

Examples include:

• Industrial machinery and construction equipment
• Firearms and explosions
• Concerts and loud entertainment venues
• Power tools and loud engines
• Headphones used at excessive volume

Noise-induced hearing loss may affect both ears, although the amount of damage can differ depending on how each ear was exposed.

Using appropriate hearing protection and reducing hazardous noise exposure can help prevent additional damage.

3. Genetic Conditions

Some genetic conditions cause hearing loss in both ears.

Hearing loss may be present at birth, develop during childhood, or become noticeable later in life.

One example is Usher syndrome, a group of inherited conditions involving hearing loss and progressive vision loss from retinitis pigmentosa. Some forms also affect balance.

Not everyone with bilateral hearing loss has a genetic condition, and genetic testing is not necessary for every patient.

Genetic evaluation may be considered when hearing loss begins early, occurs in multiple family members, or is accompanied by other suggestive medical findings.

4. Medications That Can Affect Hearing

Certain medications can damage the inner ear or auditory system. These are sometimes called ototoxic medications.

Examples include some chemotherapy medications, aminoglycoside antibiotics, and certain other drugs used for specific medical conditions.

The risk depends on the medication, dose, duration, individual susceptibility, and other health factors.

Do not stop a prescribed medication without consulting the prescribing clinician. Hearing monitoring may be recommended for people receiving treatments with known ototoxic risks.

5. Infections and Other Medical Conditions

Some infections, including bacterial meningitis, can cause permanent sensorineural hearing loss.

Other conditions affecting the middle ear, inner ear, or auditory nerve may also produce hearing loss in both ears.

Head injuries and certain systemic or autoimmune conditions are additional possible contributors.

When hearing loss develops rapidly, fluctuates, or occurs alongside neurological symptoms, medical assessment may be especially important.

What Are the Symptoms of Bilateral Hearing Loss?

Symptoms vary with the type and degree of hearing loss.

Common signs include:

• Frequently asking people to repeat themselves
• Difficulty understanding conversations in noisy environments
• Needing a higher television or telephone volume
• Feeling that people are mumbling
• Missing quieter environmental sounds
• Difficulty following group conversations
• Experiencing tinnitus alongside hearing difficulties
• Feeling tired after prolonged listening

Some people also have difficulty locating where sounds originate, particularly when hearing sensitivity differs between ears.

For broader guidance, see our article on early warning signs of cognitive and hearing changes.

How Bilateral Hearing Loss Affects Children

Children may have difficulty hearing speech, following classroom instructions, or developing spoken language when appropriate communication access is not available.

Possible warning signs include inconsistent responses to sound, concerns about speech and language milestones, and difficulty following verbal instructions.

These signs can have several explanations and should not be used to diagnose hearing loss without professional testing.

Children with suspected hearing difficulties should receive an age-appropriate audiological evaluation.

Early access to appropriate spoken or signed language and family-centered intervention is important for communication development.

How Is Bilateral Hearing Loss Diagnosed?

An audiologist can evaluate hearing in each ear separately and determine whether the loss is bilateral, symmetrical, or asymmetrical.

A comprehensive assessment may include:

Pure-Tone Audiometry

Pure-tone audiometry measures the quietest sounds someone can detect at different pitches.

The results are plotted on an audiogram, which shows hearing thresholds for each ear.

Air-conduction and bone-conduction testing help distinguish conductive from sensorineural components.

Speech Audiometry

Speech testing provides information about how well a person recognizes spoken words.

Speech-in-noise testing may also be useful when understanding conversation in background noise is a major concern.

Tympanometry

Tympanometry evaluates aspects of middle-ear function and may help identify conditions such as middle-ear fluid.

Otoacoustic Emissions and Other Tests

Otoacoustic emissions testing provides information about outer hair cell function in the cochlea.

Auditory brainstem response testing may be appropriate in selected cases, especially when behavioral hearing testing is difficult or particular auditory pathway conditions are suspected.

When Are Imaging or Genetic Tests Needed?

CT or MRI examinations are not routinely required for every person with bilateral hearing loss.

An ENT specialist may recommend imaging when clinical findings suggest certain structural, neurological, or other medical conditions.

Genetic testing may be appropriate in selected children or adults with suspected inherited hearing loss.

Can Bilateral Hearing Loss Be Reversed?

Whether hearing loss can improve depends on its cause.

Some conductive hearing problems, such as earwax blockage or certain middle-ear conditions, may improve with appropriate treatment.

Permanent sensorineural hearing loss from damage to inner-ear sensory structures generally cannot be reversed with current standard medical treatment.

Sudden sensorineural hearing loss is an important exception because prompt treatment may improve recovery in some cases.

Urgent warning: If hearing suddenly decreases in one or both ears, seek urgent medical evaluation, preferably the same day. Do not assume the change is caused by aging, congestion, or earwax.

See the American Academy of Otolaryngology–Head and Neck Surgery’s sudden hearing loss guideline for clinical guidance.

What Treatments Help Bilateral Hearing Loss?

Treatment depends on the underlying condition, severity, hearing in each ear, and individual communication needs.

Hearing Aids for Both Ears

When both ears have hearing loss that can benefit from amplification, two hearing aids are generally recommended.

Using hearing aids in both ears may provide a more natural listening experience and improve access to sounds arriving from different directions.

However, individual outcomes vary. Some people have different hearing needs in each ear or medical circumstances that require another approach.

An audiologist can evaluate whether one or two devices are appropriate.

According to the NIDCD’s hearing aid guidance, two hearing aids are generally recommended when both ears have hearing loss because hearing with both ears helps with speech understanding and sound localization.

Hearing aids do not reverse permanent hearing loss or guarantee normal hearing.

Prescription vs. Over-the-Counter Hearing Aids

Prescription hearing aids can be individually programmed and verified by a hearing professional.

In the United States, FDA-regulated over-the-counter hearing aids are intended for adults ages 18 and older with perceived mild to moderate hearing loss.

OTC hearing aids are not intended for children or for adults with severe hearing loss.

Professional evaluation is particularly important when hearing differs substantially between ears, changes suddenly, or is accompanied by other concerning symptoms.

Cochlear Implants

Cochlear implants may be appropriate for selected children and adults with substantial sensorineural hearing loss who receive limited benefit from appropriately fitted hearing aids.

Unlike hearing aids, cochlear implants use electrical stimulation to provide sound information through the auditory nerve.

Eligibility depends on hearing thresholds, speech recognition results, medical considerations, and device-specific indications.

Some individuals with hearing loss in both ears may qualify for one or two cochlear implants, depending on their circumstances.

Implantation requires surgery, programming, and rehabilitation. Results vary, and a cochlear implant does not restore normal hearing.

See the FDA’s explanation of cochlear implant benefits and risks.

Bone-Conduction Hearing Devices

Bone-conduction devices may be appropriate for selected people with conductive or mixed hearing loss, or certain cases of single-sided deafness.

They transmit vibrations through the skull to the inner ear, bypassing the outer and middle ear.

They are not routinely used as a replacement for conventional hearing aids in people with bilateral sensorineural hearing loss.

Eligibility depends on hearing thresholds, anatomy, and the specific device.

Other Specialized Hearing Devices

Some people may qualify for electric-acoustic stimulation systems or implantable middle-ear devices.

These options have specialized indications and are not appropriate for everyone with bilateral hearing loss.

A hearing specialist can explain whether they offer a reasonable benefit compared with conventional amplification.

Medical and Surgical Treatment

Medical treatment may be appropriate when hearing loss results from an identifiable condition such as middle-ear infection, fluid, or another treatable disorder.

Some structural problems may require surgical evaluation.

For sudden sensorineural hearing loss, a clinician may consider corticosteroid treatment after evaluating the diagnosis and individual risks.

Such treatment is time-sensitive, but it is not appropriate for every type of bilateral hearing loss.

How Does Hearing Rehabilitation Help?

Hearing rehabilitation may involve hearing technology, communication training, counseling, assistive devices, and follow-up support.

Learning to use hearing aids or cochlear implants can take time, particularly when hearing difficulties have been present for years.

Auditory training and rehabilitation may help some people adapt to new sound information.

The brain’s ability to change with experience is known as neuroplasticity, although neuroplasticity alone does not guarantee improvement in speech understanding.

For background, see our guide to what neuroplasticity is and how it works.

Is Bilateral Hearing Loss the Same as Auditory Processing Disorder?

No. Bilateral hearing loss describes measurable hearing loss affecting both ears.

Auditory processing disorder (APD) involves difficulties processing auditory information within the central auditory nervous system.

A person with APD may have normal conventional hearing thresholds but struggle with particular listening tasks.

Symptoms can overlap, so appropriate testing is necessary to determine which factors are contributing to communication difficulties.

Learn more in our article on auditory processing disorder (APD).

How Can You Manage Bilateral Hearing Loss in Daily Life?

Communication strategies can make everyday situations easier, whether or not someone uses hearing technology.

• Face the person speaking whenever possible.
• Reduce background noise during important conversations.
• Ask others to speak clearly rather than shouting.
• Use television and video captions.
• Choose quieter seating areas in restaurants.
• Consider remote microphone technology for meetings and classrooms.
• Request written instructions when necessary.
• Use accessible alerts for important sounds such as smoke alarms and doorbells.
• Attend recommended audiology follow-up appointments.

Signed languages, speechreading, and other communication approaches may also be valuable depending on individual needs and preferences.

Does Bilateral Hearing Loss Affect Quality of Life?

Difficulty hearing can affect communication, social participation, relationships, and work or school activities.

Some people experience listening fatigue because understanding unclear speech requires additional concentration.

Others may avoid noisy social situations or experience frustration when conversations become difficult.

These experiences are not universal, and hearing loss does not determine a person’s abilities or quality of life.

Appropriate communication access, technology, accommodations, and family support can help people participate in activities that matter to them.

Why Are Regular Hearing Evaluations Important?

Some forms of bilateral hearing loss remain relatively stable, while others progress.

Follow-up assessments allow an audiologist to compare current hearing thresholds with previous results.

They also help identify changes in speech understanding and determine whether hearing technology requires adjustment.

The appropriate follow-up schedule depends on age, the cause and severity of hearing loss, symptoms, and individual medical circumstances.

Frequently Asked Questions

Is bilateral hearing loss permanent?

Not always. Some conductive hearing conditions are treatable. Permanent sensorineural hearing loss generally cannot be reversed with current standard treatments, although hearing technology may improve access to sound.

Can bilateral hearing loss affect one ear more than the other?

Yes. This is called asymmetrical bilateral hearing loss. Both ears have hearing loss, but the severity or frequency pattern differs. Unexplained asymmetry may require further medical evaluation.

What is the difference between bilateral and unilateral hearing loss?

Bilateral hearing loss affects both ears. Unilateral hearing loss affects one ear while the other has hearing within the normal range. Both can interfere with communication and sound localization.

Are two hearing aids better than one?

For people with aidable hearing loss in both ears, two hearing aids are generally recommended. However, the most appropriate arrangement depends on hearing thresholds, speech understanding, comfort, and individual circumstances.

Can bilateral hearing loss develop suddenly?

Yes, although sudden hearing loss in both ears is uncommon. Any sudden reduction in hearing requires urgent medical evaluation because some causes need time-sensitive treatment.

Can children be born with bilateral hearing loss?

Yes. Bilateral hearing loss can be congenital and may involve genetic conditions, infections during pregnancy, structural differences, or other causes. Newborn hearing screening and appropriate follow-up are important.

Does bilateral hearing loss always get worse?

No. Some forms remain stable, while others progress. The underlying cause, additional noise exposure, medical conditions, and other factors may influence changes over time.

Can bilateral hearing loss cause tinnitus?

Bilateral hearing loss and tinnitus can occur together, particularly with age-related or noise-induced hearing damage. However, not everyone with hearing loss experiences tinnitus, and tinnitus can occur without measurable hearing loss.

How do I know whether I have bilateral hearing loss?

A comprehensive hearing evaluation measures hearing in each ear separately and can determine whether hearing loss affects one or both ears. Symptoms alone cannot establish whether the loss is bilateral.

The Bottom Line

Bilateral hearing loss means hearing loss affects both ears. It can be symmetrical or asymmetrical, mild or profound, and conductive, sensorineural, or mixed.

Common causes include age-related changes, noise exposure, genetic conditions, medications, and certain medical disorders.

Depending on the cause, treatment may involve medical care, hearing aids, cochlear implants, assistive technology, or communication support.

If you notice persistent hearing difficulties, schedule a comprehensive hearing evaluation. If hearing changes suddenly, seek urgent medical attention rather than waiting for a routine appointment.