What Is Acquired Hearing Loss?

What Is Acquired Hearing Loss?

Acquired hearing loss is hearing loss that develops after birth. It can occur during childhood, adulthood, or later life and may develop gradually over years or suddenly within hours or days.

Common causes include aging, exposure to loud noise, infections, ear injuries, certain medications, and medical conditions affecting the ear or auditory nerve.

Acquired hearing loss may affect one ear or both ears. It can also range from mild difficulty hearing certain sounds to profound hearing loss.

Some forms are temporary or treatable, while others involve permanent damage to the inner ear or auditory nerve.

The key point: Acquired hearing loss describes when hearing loss develops, not its cause or severity. A professional hearing evaluation can identify the type of hearing loss and help determine which treatments or communication supports may be appropriate.

How Is Acquired Hearing Loss Different From Congenital Hearing Loss?

The main distinction is when hearing loss begins.

• Congenital hearing loss: Hearing loss that is present at birth, even if it is not identified immediately.
• Acquired hearing loss: Hearing loss that develops after birth.

Both can be caused by genetic or non-genetic factors.

For example, a genetic condition may cause hearing loss to develop during childhood rather than being present at birth.

Likewise, a child may acquire hearing loss following an infection or exposure to a medication that affects hearing.

The terms acquired and congenital do not indicate whether hearing loss is temporary, permanent, mild, or severe.

What Are the Types of Acquired Hearing Loss?

Healthcare professionals classify hearing loss partly according to which structures of the hearing system are affected.

Conductive Hearing Loss

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

Possible causes include:

• Impacted earwax
• Middle-ear fluid
• Certain ear infections
• Eardrum perforation
• Otosclerosis
• Other conditions affecting middle-ear structures

Some forms of conductive hearing loss improve with medical treatment, removal of an obstruction, or surgery.

Sensorineural Hearing Loss

Sensorineural hearing loss involves the inner ear or auditory nerve.

Common contributors include aging, loud noise exposure, certain medications, and some infections or other medical conditions.

Permanent sensorineural hearing loss generally cannot be reversed with current standard treatments.

However, hearing aids, cochlear implants, and other supports may improve access to sound and communication.

Mixed Hearing Loss

Mixed hearing loss involves both conductive and sensorineural components.

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

Treatment depends on identifying and addressing the different components.

What Causes Acquired Hearing Loss?

Several factors can contribute to hearing loss after birth. Sometimes a single cause can be identified, while other cases involve multiple contributing factors.

1. Age-Related Hearing Changes

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

Changes in the cochlea, auditory nerve, and other parts of the hearing system can make certain sounds harder to detect and speech more difficult to understand.

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

Age-related hearing loss is one of the most common causes of acquired hearing loss in older adults.

2. Loud Noise Exposure

Repeated exposure to hazardous noise can damage sensory structures inside the cochlea.

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

Hearing damage may develop gradually after repeated exposure or occur suddenly after an extremely loud event.

Reducing hazardous noise exposure and using appropriate hearing protection can help prevent additional damage.

For prevention guidance, see the CDC’s information on noise-induced hearing loss.

3. Ear Infections and Middle-Ear Conditions

Some acquired hearing loss results from conditions affecting the outer or middle ear.

Middle-ear infections can cause inflammation and fluid accumulation behind the eardrum, temporarily interfering with sound transmission.

Outer-ear infections may also reduce hearing when swelling or debris obstructs the ear canal.

Some cases improve after treatment, although persistent or complicated infections may require additional medical care.

4. Medications That Can Affect Hearing

Some medications can damage the inner ear or other structures involved in hearing. These medications are sometimes described as ototoxic.

Examples include certain chemotherapy drugs and specific antibiotics used to treat serious infections.

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

Do not stop or change prescribed medication without speaking with the prescribing clinician.

People receiving potentially ototoxic treatments may need hearing monitoring when recommended by their healthcare team.

5. Head and Ear Injuries

Head injuries, eardrum perforations, and other trauma can cause hearing loss.

An injury may affect the outer or middle ear, the cochlea, the auditory nerve, or several structures simultaneously.

The resulting hearing loss may be temporary or permanent depending on the injury.

Sudden hearing changes following head trauma require prompt medical assessment.

6. Inner-Ear and Neurological Conditions

Certain disorders involving the inner ear or auditory pathways may cause acquired hearing loss.

Examples include Ménière’s disease, some autoimmune conditions, and vestibular schwannoma.

These conditions are not among the most common explanations for gradual hearing loss, but they may be important when symptoms have unusual features.

Can Acquired Hearing Loss Develop Suddenly?

Yes. Some acquired hearing loss develops rapidly.

Sudden hearing loss may result from a conductive condition, such as a blockage, or from a problem involving the inner ear or auditory nerve.

Sudden sensorineural hearing loss is especially important because it requires urgent medical evaluation.

What Is Sudden Sensorineural Hearing Loss?

Sudden sensorineural hearing loss (SSNHL), sometimes called sudden deafness, is a rapid reduction in hearing caused by a problem involving the inner ear or auditory nerve.

It usually affects one ear, although both ears can occasionally be involved.

A commonly used audiometric definition involves a hearing decrease of at least 30 decibels across three consecutive test frequencies occurring within 72 hours.

However, someone with a smaller or less easily measured sudden hearing change may still need urgent evaluation.

The 72-hour period is part of a diagnostic definition. It is not a reason to wait 72 hours before seeking care.

What Causes Sudden Sensorineural Hearing Loss?

Many cases have no clearly identifiable cause and are described as idiopathic sudden sensorineural hearing loss.

Possible identifiable causes include infections, injuries, autoimmune conditions, and certain neurological or inner-ear disorders.

A hearing evaluation and medical assessment help determine whether the loss is sensorineural and whether additional investigation is needed.

For details, see the National Institute on Deafness and Other Communication Disorders (NIDCD) guide to sudden deafness.

When Is Sudden Hearing Loss an Emergency?

If hearing suddenly decreases in one or both ears, seek urgent medical evaluation, preferably the same day.

Do not assume the problem is caused by earwax, allergies, congestion, or an ear infection without assessment.

Sudden hearing loss accompanied by facial weakness, difficulty speaking, severe imbalance, or other new neurological symptoms requires emergency medical assessment.

Prompt evaluation matters because some forms of sudden sensorineural hearing loss may respond to time-sensitive treatment.

Other Medical Conditions That Can Cause Acquired Hearing Loss

Ménière’s Disease

Ménière’s disease is an inner-ear disorder associated with episodes of vertigo, fluctuating hearing symptoms, tinnitus, and a sensation of ear fullness.

Hearing loss may fluctuate early in the condition and become more persistent over time.

Diagnosis depends on the pattern of symptoms and appropriate medical and audiological assessment.

Autoimmune Inner-Ear Conditions

Some immune-mediated disorders may affect the inner ear and produce hearing changes.

Hearing loss associated with suspected autoimmune inner-ear disease may develop over days, weeks, or months and sometimes affects both ears.

Diagnosis can be challenging, and no single symptom confirms an autoimmune cause.

Treatment requires specialist evaluation because immune-suppressing medications have important potential risks.

Vestibular Schwannoma

A vestibular schwannoma, sometimes called an acoustic neuroma, is a usually benign tumor that develops from Schwann cells associated with the vestibular portion of the eighth cranial nerve.

It may cause progressive hearing loss, tinnitus, or balance-related symptoms, often affecting one ear.

An MRI may be recommended when clinical findings raise concern about this or another condition affecting the auditory pathways.

Treatment decisions may involve monitoring, radiation treatment, or surgery. Hearing recovery is not guaranteed.

Otosclerosis

Otosclerosis involves abnormal bone remodeling in the region of the middle ear and sometimes the inner ear.

It can interfere with movement of the stapes, one of the small hearing bones, and cause conductive or mixed hearing loss.

Depending on the circumstances, hearing aids or surgery may be considered.

What Are the Signs of Acquired Hearing Loss?

Symptoms depend on whether hearing loss develops suddenly or gradually and which parts of the auditory system are affected.

Possible signs include:

• Frequently asking people to repeat themselves
• Difficulty understanding conversations in background noise
• Needing a higher television or telephone volume
• Sounds appearing muffled or less clear
• Difficulty hearing certain pitches or environmental sounds
• Tinnitus accompanying hearing changes
• Difficulty understanding speech on one side
• Feeling tired after prolonged listening

Some people also experience dizziness or ear fullness, depending on the underlying cause.

These symptoms do not establish a particular diagnosis.

For more information, see our article on early warning signs of cognitive and hearing changes.

Can Acquired Hearing Loss Affect Only One Ear?

Yes. Acquired hearing loss may be unilateral, affecting one ear, or bilateral, affecting both ears.

Some causes, such as age-related hearing loss, commonly affect both ears.

Others, including certain injuries, infections, and vestibular schwannomas, may primarily affect one ear.

Unexplained hearing loss that is substantially worse in one ear may require additional medical evaluation.

Neither unilateral nor bilateral hearing loss establishes the underlying cause by itself.

How Is Acquired Hearing Loss Diagnosed?

A comprehensive hearing evaluation helps establish the degree, type, and pattern of hearing loss.

The clinician also considers when symptoms began, how quickly they developed, medical history, medication use, and possible noise exposure.

Ear Examination

A healthcare professional examines the ear canal and eardrum for visible problems such as earwax blockage, inflammation, or structural abnormalities.

A normal-looking eardrum does not rule out inner-ear or auditory nerve problems.

Pure-Tone Audiometry

Pure-tone testing measures the quietest sounds someone can detect at different frequencies.

The results are plotted on an audiogram.

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

Speech Audiometry

Speech audiometry provides information about speech detection and word recognition.

Speech-in-noise testing may also help assess communication difficulties in challenging listening environments.

Tympanometry

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

Imaging and Additional Medical Tests

CT scans, MRI examinations, and laboratory studies are not automatically necessary for every person with acquired hearing loss.

Additional testing depends on the history, examination, audiogram, and suspected underlying conditions.

For adults with sudden sensorineural hearing loss, the American Academy of Otolaryngology–Head and Neck Surgery recommends evaluating for retrocochlear pathology using MRI or auditory brainstem response testing.

The guideline recommends against routine head CT and routine laboratory testing in the initial assessment of otherwise unexplained sudden sensorineural hearing loss.

Can Acquired Hearing Loss Be Reversed?

Sometimes, depending on its cause.

Hearing loss caused by impacted earwax or certain middle-ear conditions may improve after appropriate treatment.

Permanent sensorineural hearing loss generally cannot be reversed with current standard medical treatment.

Sudden sensorineural hearing loss may partially or substantially improve in some individuals, including with appropriate medical treatment, although recovery cannot be guaranteed.

Determining the cause is essential before choosing treatment.

How Is Acquired Hearing Loss Treated?

Treatment depends on the type, severity, cause, and timing of hearing loss.

Treating Reversible Causes

Some conductive conditions may respond to medical or surgical treatment.

Examples include professional earwax removal, appropriate treatment of infections, and selected procedures for middle-ear disorders.

The likelihood of hearing improvement depends on whether other hearing problems are also present.

Corticosteroids for Sudden Sensorineural Hearing Loss

Corticosteroids may be considered for adults with sudden sensorineural hearing loss after clinical evaluation.

According to the 2019 AAO-HNS clinical practice guideline, clinicians may offer corticosteroids as initial treatment within two weeks of symptom onset.

For individuals with incomplete recovery, intratympanic steroid treatment may be offered as salvage therapy within two to six weeks after onset.

These are clinical treatment windows, not reasons to delay evaluation.

Decisions depend on medical circumstances, potential benefits, contraindications, and treatment risks.

For the full clinical guidance, see the AAO-HNS Sudden Hearing Loss Clinical Practice Guideline.

Hearing Aids

Hearing aids are a common management option for permanent hearing loss that may benefit from amplification.

Modern devices can be programmed to provide different amounts of amplification across frequencies.

Properly fitted hearing aids may improve access to speech and other sounds, but they do not repair damaged inner-ear hair cells or restore normal hearing.

Cochlear Implants

Cochlear implants may be appropriate for selected people with substantial sensorineural hearing loss who receive insufficient benefit from appropriately fitted hearing aids.

These devices use electrical stimulation to provide auditory information through the hearing nerve.

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

Implantation requires surgery and rehabilitation, and results vary.

Devices for Single-Sided Hearing Loss

Some people with hearing loss in one ear may benefit from CROS hearing aids or selected bone-conduction devices.

These technologies can help make sounds arriving from the poorer-hearing side more accessible.

However, they generally do not restore normal hearing or normal sound localization.

Other treatment options may be considered depending on hearing levels and candidacy.

How Does Hearing Rehabilitation Help?

Hearing rehabilitation can involve hearing technology, communication strategies, assistive listening devices, and professional counseling.

Some people also benefit from auditory training or other exercises designed to practice listening skills.

The brain can adapt through learning and experience, a property known as neuroplasticity.

However, adaptation does not guarantee that hearing technology or training will restore normal speech understanding.

Learn more in our article on what neuroplasticity is and how it works.

Can Acquired Hearing Loss Be Prevented?

Not every cause of acquired hearing loss is preventable.

However, certain measures can reduce avoidable risks.

• Use appropriately fitted hearing protection around hazardous noise.
• Reduce headphone volume and limit prolonged loud listening.
• Follow workplace hearing conservation requirements.
• Seek medical attention for persistent ear infections or injuries.
• Discuss hearing monitoring when taking potentially ototoxic medications.
• Attend recommended hearing evaluations if you have significant risk factors.

These measures cannot prevent every genetic, age-related, or medical cause of hearing loss, but they can help protect hearing from avoidable damage.

When Should You See an Audiologist or Doctor?

Schedule a hearing evaluation if you notice persistent difficulty understanding speech, changing hearing sensitivity, or new communication problems.

Medical evaluation is particularly important when hearing loss is unexplained, significantly different between ears, or accompanied by other concerning symptoms.

Children with suspected acquired hearing loss should receive age-appropriate testing rather than waiting for speech or educational difficulties to become more pronounced.

Seek urgent care for sudden hearing loss, preferably the same day. Sudden hearing changes should not be assumed to be caused by wax, congestion, or ordinary aging.

Frequently Asked Questions

What is the main difference between acquired and congenital hearing loss?

Congenital hearing loss is present at birth. Acquired hearing loss develops afterward. Either can involve conductive, sensorineural, or mixed hearing loss.

Can acquired hearing loss be permanent?

Yes. Permanent sensorineural hearing loss can result from aging, hazardous noise exposure, some infections, injuries, and other causes. Certain conductive conditions may be temporary or treatable.

Can acquired hearing loss happen overnight?

Yes. Sudden sensorineural hearing loss can develop within hours or over a few days. Any sudden hearing change warrants urgent medical evaluation.

Is acquired hearing loss always caused by aging?

No. Aging is a common cause, but acquired hearing loss can also result from noise, infections, injuries, medications, and other medical conditions. It can occur at any age.

Can acquired hearing loss affect children?

Yes. Children may develop hearing loss after birth because of infections, injuries, certain medical treatments, or other conditions. Early identification and access to appropriate communication support are important.

Can earwax removal restore hearing?

When impacted earwax is responsible for conductive hearing loss, professional removal may restore hearing to its previous level. However, removal will not reverse an unrelated inner-ear hearing impairment.

Can hearing aids cure acquired hearing loss?

No. Hearing aids can improve access to sound and may improve speech understanding, but they do not repair permanent inner-ear damage or cure the underlying hearing loss.

Is sudden hearing loss a medical emergency?

Yes. Sudden sensorineural hearing loss requires prompt medical evaluation because treatment may be time-sensitive. Seek care immediately rather than waiting to see whether hearing returns on its own.

The Bottom Line

Acquired hearing loss is hearing loss that develops after birth. It may be sudden or gradual, affect one or both ears, and result from several different medical or environmental factors.

Some causes are treatable, while permanent sensorineural hearing loss generally requires rehabilitation or hearing technology rather than a cure.

A comprehensive hearing evaluation can identify the pattern and degree of hearing loss and guide appropriate care.

If hearing changes suddenly, seek urgent medical attention. For gradual or persistent hearing difficulties, schedule a professional hearing evaluation rather than relying on guesswork.