Conductive Hearing Loss: Causes, Symptoms, and Treatment

What is conductive hearing loss?

Conductive hearing loss occurs when a problem in the outer or middle ear prevents sound from reaching the inner ear efficiently. Unlike sensorineural hearing loss, which results from damage to the inner ear or auditory nerve, conductive hearing loss affects the pathway that carries sound to the cochlea — the inner ear structure that converts sound into nerve signals.

In practical terms, sound may seem quieter, muffled, or distant. Many people describe it as feeling like they have a blocked ear or are hearing through a layer of cotton. Because the inner ear and auditory nerve are often unaffected, hearing can frequently improve once the underlying cause is treated.

How sound normally travels to your inner ear

To understand conductive hearing loss, it helps to know how hearing normally works.

Sound waves enter the ear canal and strike the eardrum, causing it to vibrate. Those vibrations travel through three tiny middle ear bones — the malleus, incus, and stapes (collectively called the ossicles) — before reaching the cochlea in the inner ear. The cochlea then converts those vibrations into electrical signals that the brain interprets as sound.

Conductive hearing loss can occur anywhere along this pathway, from a blocked ear canal to a problem affecting the eardrum or middle ear bones.

Common causes of conductive hearing loss

Some causes of conductive hearing loss are temporary and easily treated, while others may require medical or surgical intervention. Below are seven of the most common causes.

Earwax buildup 

One of the most common and easily treated causes of conductive hearing loss is earwax buildup. Hearing may become noticeably muffled when earwax blocks the ear canal. Audiologists and physicians can safely remove impacted earwax through irrigation, suction, or manual extraction.

Ear infections

Middle ear infections are a leading cause of conductive hearing loss, particularly in children, though adults are affected too. Acute ear infection causes fluid or pus to build up behind the eardrum, dampening its movement. When fluid persists without infection — a condition called otitis media with effusion, or “glue ear” — it can cause months of reduced hearing. Treatment ranges from watchful waiting and antibiotics to surgical placement of pressure-equalizing (PE) tubes.

Perforated eardrum

A hole or tear in the eardrum can occur due to infection, sudden pressure changes, injury, or trauma. Small perforations often heal on their own, while larger perforations may require surgical repair through a procedure called tympanoplasty.

Otosclerosis

Otosclerosis is a condition in which abnormal bone growth prevents the stapes, one of the middle ear bones, from vibrating normally. According to the NIDCD, otosclerosis affects approximately 3 million Americans, is about twice as common in women as in men,  and tends to run in families. It typically presents in early-to-middle adulthood and can be surgically treated through a procedure called a stapedectomy, in which the fixed stapes is replaced with a prosthesis.

Cholesteatoma

A cholesteatoma is an abnormal, noncancerous skin growth that develops in the middle ear, often as a result of repeated ear infections or chronic eustachian tube dysfunction. Over time, it can damage surrounding structures and cause progressive hearing loss. Surgical removal is usually required.

Eustachian tube dysfunction

The eustachian tube connects the middle ear to the back of the throat and is responsible for equalizing pressure on both sides of the eardrum. When it doesn’t open and close properly — due to allergies, a cold, or structural issues — pressure imbalances can cause muffled hearing, a sensation of fullness, or pain. This is the same pressure-related feeling many people notice during air travel.  Treatment depends on the underlying cause and may include observation, allergy management, medication, or referral to an ENT specialist.

Congenital and structural causes

Some people are born with differences affecting the outer or middle ear, such as microtia (an underdeveloped outer ear), atresia (a closed or absent ear canal), or malformed middle ear bones. These conditions are often identified through newborn hearing screening and may be managed with surgery, hearing devices, or both.

Symptoms: what conductive hearing loss feels like

The hallmark symptom of conductive hearing loss is that sounds seem muffled, distant, or dampened — as though someone has turned down the volume. Depending on the underlying cause, you may also experience:

• Difficulty hearing, particularly in quieter environments
• A feeling of fullness or pressure in the ear
• Hearing your own voice differently, such as sounding louder or echoing
• Ear pain or discharge (when infection is the underlying cause)
• Hearing better in one ear than the other (conductive hearing loss can be unilateral)
• Tinnitus (ringing or buzzing), though this is more common with sensorineural hearing loss

One more interesting sign of conductive hearing loss is paracusis Willisii, a phenomenon in which speech may seem easier to understand in noisy environments than in quiet ones. This is thought to occur because conductive hearing loss often affects low-frequency sounds, making background noise less noticeable to the listener. People also tend to speak louder in noisy environments, which may further improve speech audibility.

How conductive hearing loss is diagnosed

Diagnosing conductive hearing loss begins with a review of your symptoms, medical history, and an examination of your ears. During the appointment, an audiologist may use an otoscope to look for visible causes of hearing loss, such as earwax buildup, fluid behind the eardrum, or structural abnormalities.

The primary diagnostic test is pure-tone audiometry, which measures the softest sounds you can hear through both air conduction (sound traveling through the ear canal) and bone conduction (vibrations sent directly to the cochlea through a device placed behind the ear). In conductive hearing loss, bone conduction thresholds are typically normal while air conduction thresholds are reduced— this gap between the two, called the air-bone gap, is a defining diagnostic marker.

Audiologists may also perform tympanometry, which evaluates how well the eardrum moves in response to changes in air pressure, and acoustic reflex testing, which helps assess middle ear function. Together, these hearing tests allow a skilled audiologist to pinpoint where in the conductive pathway the problem lies.

From an audiologist: why identifying the cause matters

Jessica Hinson, Au.D., a licensed audiologist and medical reviewer for audiologists.org, emphasizes that identifying the underlying cause of conductive hearing loss is one of the most important steps in determining the appropriate treatment plan.

“Accurately determining the cause of conductive hearing loss can affect treatment outcomes tremendously. For some conductive losses, like loss due to mild otitis media (ear infection), a wait-and-see treatment plan may be appropriate as light fluid and mild ear infections may resolve on their own. In other cases, such as a cholesteatoma, delaying treatment can allow additional damage to occur within the middle ear and may result in a more complex surgical repair.

Before pursuing hearing devices, hearing loss should always be evaluated by a professional who can determine whether the loss is conductive, sensorineural, or mixed, and to identify the underlying cause. Those with treatable loss may choose to do so before considering prescription or over-the-counter hearing aids.

Delaying diagnosis can result in worsening hearing loss, money spent on unnecessary hearing devices, or overly invasive treatment plans before exploring potentially correctable causes.”

Treatment options for conductive hearing loss

Treatment for conductive hearing loss depends on the underlying cause. In some cases, hearing improves once the blockage, infection, fluid, or structural problem is treated. In other cases, hearing technology may be recommended to improve access to sound.

Medical treatment

Some causes of conductive hearing loss can be treated with medical care. For example, earwax can often be removed safely in the office, while ear infections or inflammation are typically treated with antibiotics or antifungals. Eustachian tube dysfunction may be managed by addressing the underlying cause, such as allergies, infection, or pressure changes.

Surgical treatment

Some conditions, including a perforated eardrum, otosclerosis, cholesteatoma, or congenital ear canal differences, may require surgery. Common procedures include tympanoplasty to repair the eardrum, stapedectomy for otosclerosis, and canaloplasty to reconstruct the ear canal. When appropriate and successful, surgery can significantly improve hearing.

Hearing aids and bone-conduction devices 

When medical or surgical treatment is not possible, not preferred, or does not fully restore hearing, hearing technology may help. Traditional hearing aids can be effective for many people with conductive hearing loss because the inner ear and auditory nerve are often able to process amplified sound.

For some patients, especially those who cannot wear a traditional hearing aid in the ear canal, bone-conduction hearing aids (BAHAs) may be recommended. These devices send sound vibrations through the bones of the skull to the inner ear, bypassing the outer and middle ear. Depending on the device, these systems may be surgical, nonsurgical, bone-anchored, or worn externally.

Conductive vs. sensorineural hearing loss: key differences

Conductive and sensorineural hearing loss affect different parts of the hearing system and often require different treatment approaches. Understanding the differences can help explain why some types of hearing loss are medically treatable while others are typically managed with hearing technology.

Mixed hearing loss — a combination of both conductive and sensorineural hearing loss  — is also possible and requires a tailored treatment approach.

When to see an audiologist

Any unexplained or sudden change in hearing warrants a prompt evaluation. If you’re experiencing muffled hearing, a persistent feeling of fullness in the ear, difficulty hearing from one ear, or hearing changes that do not improve, it’s a good idea to schedule a hearing evaluation.

An audiologist can determine whether the cause is conductive, sensorineural, or mixed hearing loss and help guide the next steps for treatment. Depending on the underlying cause, this may include medical referral, hearing technology, or ongoing monitoring.

A comprehensive hearing evaluation typically takes about an hour and provides a detailed picture of your hearing health. For many causes of conductive hearing loss, early diagnosis and treatment can help prevent complications and improve outcomes.