Otosclerosis

What is otosclerosis?

Otosclerosis is a condition in which abnormal bone growth develops inside the middle ear, most often around a tiny hearing bone called the stapes (the smallest bone in the human body, sometimes called the stirrup). In a healthy ear, sound waves travel down the ear canal, vibrate the eardrum, and pass through three small bones — the malleus, incus, and stapes — into the inner ear, where they are converted into nerve signals. In otosclerosis, new spongy bone forms around the base of the stapes and gradually fixes it in place, so it can no longer vibrate freely. When this happens, sound is not transmitted efficiently to the inner ear, and hearing loss develops. Doctors call this type of hearing loss conductive hearing loss, because the problem lies in how sound is conducted, not in the hearing nerve itself.

In some people, the abnormal bone remodeling also affects the cochlea, the snail-shaped organ of the inner ear that houses the hearing nerve cells. When this occurs, a person may develop sensorineural hearing loss (loss caused by damage to the inner ear or nerve pathways) in addition to conductive loss. This combination is often called cochlear otosclerosis or mixed hearing loss.

Understanding what is otosclerosis begins with knowing who it typically affects. The condition usually appears in young and middle-aged adults, most often between the late teens and the forties. It is more commonly diagnosed in women than in men, and it frequently runs in families. In many people it affects both ears, although one ear may be involved earlier or more severely than the other. Otosclerosis is one of the more common causes of progressive hearing loss in young adults, and it is generally a slowly developing condition rather than a sudden one.

Symptoms of otosclerosis

Otosclerosis symptoms usually develop gradually, often over several years, and many people first notice them as subtle difficulty hearing quiet sounds or soft voices. Because the change is slow, some people adapt without realizing how much their hearing has declined until family members or colleagues point it out.

Common otosclerosis symptoms include:

• Gradual hearing loss — usually starting with low-pitched sounds and soft speech, often in one ear first and later in both.
• Tinnitus — a ringing, buzzing, hissing, or roaring sound in the ear that has no external source.
• Difficulty hearing whispers or low voices — while louder sounds may still be heard reasonably well, at least in early stages.
• Speaking quietly — some people with otosclerosis speak in a softer voice because they hear their own voice loudly through bone conduction (sound traveling through the bones of the skull).
• Hearing better in noisy environments — a phenomenon called paracusis willisii, in which background noise causes others to raise their voices, which people with conductive hearing loss may hear more easily.
• Dizziness or mild balance problems — less common, but possible when the inner ear is involved.

Symptoms can differ depending on the stage and type of the disease. In early otosclerosis, when only the stapes is becoming fixed, the hearing loss is mainly conductive and often mild. As the fixation progresses, the conductive loss typically worsens. If the abnormal bone extends into the cochlea, sensorineural hearing loss can be added, which may make sounds not only quieter but also distorted or harder to understand. Tinnitus often becomes more noticeable as the condition progresses, and in some people it can be more bothersome than the hearing loss itself. Otosclerosis does not usually cause ear pain or discharge; if those symptoms are present, another condition is more likely and should be evaluated separately.

Causes and risk factors

The exact cause of otosclerosis is not fully understood. What is known is that the condition involves abnormal remodeling of bone in the otic capsule, the dense bone that surrounds the inner ear. In healthy bone, old tissue is constantly broken down and replaced in a balanced cycle. In otosclerosis, this cycle becomes disorganized in specific areas of the ear, producing patches of softer, spongy bone that later harden and can fix the stapes in place.

Several factors are believed to contribute to otosclerosis causes and risk:

• Genetics and family history — otosclerosis often runs in families. Having a parent or sibling with the condition increases the likelihood of developing it, although not everyone who inherits the tendency will develop noticeable hearing loss.
• Sex — the condition is diagnosed more often in women than in men.
• Age — symptoms most often begin between the late teens and the forties.
• Hormonal factors — some women notice that hearing loss appears or worsens during pregnancy, which has led researchers to suspect that hormonal changes may influence the disease, although this link is not fully proven.
• Viral factors — some research has suggested a possible association between measles virus infection and otosclerosis, but this remains an area of ongoing study rather than an established cause.
• Ancestry — the condition is reported more frequently in people of European descent, although it occurs in all populations.

It is important to understand that otosclerosis is not caused by noise exposure, ear infections, earwax, or anything a person did or failed to do. It cannot be prevented by lifestyle changes, and having a risk factor does not mean the condition will definitely develop.

Diagnosis

Otosclerosis diagnosis is usually made by an ear, nose, and throat specialist (an otolaryngologist) working together with an audiologist, a professional trained in hearing testing. Because several conditions can cause similar hearing loss, doctors rely on a combination of history, examination, and specific tests rather than a single finding.

The evaluation typically includes the following steps:

• Medical history — the doctor asks when the hearing loss began, how it has changed, whether one or both ears are affected, whether there is tinnitus or dizziness, and whether relatives have similar hearing problems.
• Ear examination (otoscopy) — the doctor looks into the ear canal with a lighted instrument. In otosclerosis the eardrum usually looks normal, which helps rule out infections, eardrum perforations, and other visible problems.
• Pure-tone audiometry — a hearing test performed in a soundproof booth. It measures how well you hear tones delivered through headphones (air conduction) and through a small vibrating device placed on the bone behind the ear (bone conduction). In otosclerosis, air conduction is typically worse than bone conduction, creating what audiologists call an air-bone gap, the hallmark of conductive hearing loss. A characteristic dip in bone-conduction results at a certain pitch, known as a Carhart notch, is sometimes seen and can support the diagnosis.
• Speech testing — measures how well you understand spoken words, which helps assess how the hearing loss affects everyday communication.
• Tympanometry and acoustic reflex testing — painless tests that measure how the eardrum and middle ear respond to sound and pressure. In otosclerosis, the acoustic reflex (a small protective muscle contraction in the middle ear) is often reduced or absent because the stapes cannot move.
• Imaging — a high-resolution computed tomography (CT) scan of the temporal bone (the part of the skull containing the ear) may be ordered in some cases. It can show the areas of abnormal bone, help confirm the diagnosis when findings are unclear, assess whether the cochlea is involved, and assist with surgical planning. Imaging is not always required.

In practice, doctors often confirm otosclerosis based on the combination of progressive conductive hearing loss, a normal-looking eardrum, typical audiometry findings, and, in many cases, a family history. The definitive confirmation of stapes fixation is sometimes made only during surgery, when the surgeon can directly assess whether the stapes moves.

Treatment options

Otosclerosis treatment depends on how severe the hearing loss is, how quickly it is progressing, whether one or both ears are affected, and the person’s own preferences and overall health. There is currently no medication proven to reverse the abnormal bone growth, but there are well-established ways to manage the hearing loss effectively. Care is usually coordinated through an otorhinolaryngology (ENT) department; at Acibadem, for example, otosclerosis is managed within this specialty in cooperation with audiology services.

Watchful waiting

When hearing loss is mild and not interfering much with daily life, doctors may recommend simple monitoring, with hearing tests repeated periodically — often once a year — to track any change. Because otosclerosis usually progresses slowly, this approach allows treatment decisions to be made when and if they are truly needed.

Hearing aids

Hearing aids are a common and effective non-surgical option. They amplify sound to compensate for the conductive loss and work well for many people with otosclerosis. Hearing aids do not stop the disease from progressing, but they carry no surgical risk and can be adjusted as hearing changes. For some people, especially those who prefer to avoid surgery or who are not good surgical candidates, hearing aids remain the main long-term treatment.

Medication

Some doctors have used sodium fluoride or, less commonly, bisphosphonate medications (drugs that affect bone turnover) in an attempt to slow the progression of otosclerosis, particularly when the inner ear is involved. The evidence for these medications is limited and mixed, and they are not universally recommended. If medication is considered, your doctor will discuss the potential benefits and side effects in your individual situation.

Surgery (stapedectomy or stapedotomy)

Surgery is the most common definitive otosclerosis treatment for people with significant conductive hearing loss. The two related procedures are:

• Stapedotomy — the surgeon makes a small opening in the fixed footplate of the stapes and places a tiny prosthesis (an artificial replacement) that transmits sound vibrations to the inner ear. This is the more commonly performed technique today.
• Stapedectomy — the surgeon removes all or most of the stapes and replaces it with a prosthesis.

Both procedures are usually performed through the ear canal, often under local or general anesthesia, and typically as day surgery or with a short hospital stay. Many people experience a meaningful improvement in hearing, though results vary from person to person. As with any operation, there are risks, which your surgeon should explain fully. These can include temporary dizziness, taste disturbance (because a taste nerve runs through the middle ear), persistent tinnitus, and, rarely, a further worsening of hearing in the operated ear, including severe loss in a small minority of cases. When both ears are affected, surgeons generally operate on the worse-hearing ear first and wait before considering the second ear.

Hearing implants

In advanced cases where the cochlea is significantly involved and neither hearing aids nor stapes surgery can provide adequate hearing, a cochlear implant may be considered. This is an electronic device, placed surgically, that bypasses the damaged inner ear and stimulates the hearing nerve directly. Suitability is assessed individually through detailed testing.

Living with otosclerosis and outlook

Otosclerosis is not a life-threatening condition, and it does not usually cause complete deafness, especially when it is monitored and treated appropriately. For most people, the outlook is reasonable: hearing loss tends to progress slowly, and modern treatment — whether hearing aids or surgery — restores useful hearing in many cases. That said, the course of the disease varies from person to person, and no treatment can guarantee a specific result or stop the underlying bone process entirely.

Practical steps that often help in daily life include attending regular hearing checkups so changes are detected early, using hearing aids consistently if they have been recommended, and letting family, friends, and colleagues know about the hearing loss so they can face you when speaking and reduce background noise. Tinnitus, when present, can often be managed with counseling, sound therapy, or hearing aids, which frequently make the ringing less noticeable by improving overall hearing. People who have had stapes surgery are usually advised to protect the operated ear from sudden pressure changes for a period afterward — for example, avoiding heavy lifting, forceful nose blowing, flying, or diving until the surgeon confirms it is safe.

Women with otosclerosis who are planning pregnancy may wish to discuss the condition with their doctor, since some women report that hearing changes during pregnancy; this does not mean pregnancy is unsafe, only that hearing may need closer monitoring.

Frequently asked questions

What is otosclerosis in simple terms?

Otosclerosis is a condition in which abnormal bone grows inside the middle ear and gradually fixes the stapes, one of the tiny bones that carries sound to the inner ear. Because the bone can no longer vibrate properly, sound is not transmitted well, and hearing loss develops slowly over time. It most often affects young and middle-aged adults and frequently runs in families.

Can otosclerosis heal on its own?

Otosclerosis does not usually go away on its own, and the abnormal bone changes are not known to reverse spontaneously. However, the condition often progresses slowly, and in some people the hearing loss stabilizes for long periods. Regular hearing tests allow doctors to track any change and recommend treatment when it becomes necessary.

How serious is otosclerosis?

Otosclerosis is not dangerous to your overall health and is not a form of cancer or infection. Its main impact is on hearing and, for some people, tinnitus. While it can cause significant hearing loss if left unaddressed, effective management options exist, and complete deafness is uncommon, particularly when the condition is followed and treated by a specialist.

What are the first symptoms of otosclerosis?

The earliest otosclerosis symptoms are usually a gradual difficulty hearing soft sounds, low-pitched voices, or whispers, often in one ear first. Some people notice ringing in the ear (tinnitus), or that they hear conversation better in noisy places than in quiet ones. Because the change is slow, family members sometimes notice the hearing loss before the person does.

Is surgery the only otosclerosis treatment?

No. Treatment options range from simple monitoring for mild cases, to hearing aids, to surgery such as stapedotomy or stapedectomy for more significant conductive hearing loss. Some doctors also consider medications aimed at slowing bone changes, though the evidence for them is limited. The right approach depends on the severity of hearing loss, how it affects daily life, and your personal preferences, all discussed with your ENT specialist.

How long is recovery after stapes surgery?

Recovery varies, but many people return to routine activities within one to two weeks, while full hearing improvement may take several weeks as the ear heals and any packing material dissolves or is removed. Temporary dizziness or taste changes can occur in the early period. Your surgeon will advise you on when it is safe to fly, exercise, or return to work, and following those instructions is important for a good result.

Does otosclerosis affect both ears?

In many people, otosclerosis eventually affects both ears, although one ear is often involved earlier or more severely than the other. Some people have noticeable disease in only one ear. Because both ears can be affected over time, doctors usually monitor hearing in both ears with regular audiometry, even if only one currently shows hearing loss.

When to see a doctor

You should arrange a medical evaluation if you notice gradual hearing loss, persistent ringing in the ears, or increasing difficulty following conversations, especially if hearing problems run in your family. Early assessment allows the cause to be identified and monitored properly.

Seek medical attention promptly — the same day if possible — if you experience any of the following red-flag warning signs:

• Sudden hearing loss in one or both ears, developing over hours or a few days, which is a medical urgency that may need rapid treatment.
• Severe or spinning dizziness (vertigo), particularly with nausea, vomiting, or difficulty walking.
• Ear pain, fever, or discharge from the ear, which suggest infection or another condition rather than otosclerosis.
• Sudden worsening of hearing, new vertigo, or drainage after ear surgery, which should be reported to your surgeon without delay.
• Facial weakness or drooping on one side accompanying ear symptoms.
• Tinnitus that appears suddenly in one ear only or is accompanied by rapidly changing hearing.

Otosclerosis itself is usually a slow, manageable condition, but these warning signs can point to other problems that need urgent assessment. When in doubt, it is always safer to have new or rapidly changing ear symptoms checked by a qualified doctor.