Understanding Otosclerosis: Causes, Symptoms, and Treatment

UPDATED June 1, 2023

If you or someone you know is experiencing hearing loss, it could be due to otosclerosis.

written by

Mark Ross

Otosclerosis is a condition that affects the middle ear, leading to hearing loss. It is characterized by the abnormal growth of bone in the middle ear, which can restrict the movement of the tiny bones responsible for transmitting sound. The condition can occur in one or both ears and can cause a gradual decline in hearing over time. In this article, we will explore the various causes, symptoms, and treatment options for otosclerosis.

What is Otosclerosis?

Definition and Overview

Otosclerosis is a condition that develops in the middle ear. It is caused by the abnormal growth of bone tissue that surrounds the stapes bone, one of the three tiny bones in the middle ear. This can cause the stapes bone to become fixed, leading to hearing loss. Otosclerosis is a progressive condition that can worsen over time without proper management.

Prevalence and Demographics

Otosclerosis is relatively uncommon, affecting approximately 1 in 1,000 people. It is most commonly diagnosed in individuals between the ages of 15 and 45, and it affects women more often than men. Genetic factors are thought to play a role in the development of otosclerosis, and it is more commonly found in individuals of European descent.

Symptoms and Diagnosis

The most common symptom of otosclerosis is hearing loss, which may be gradual or sudden. Other symptoms may include tinnitus (ringing in the ears), dizziness, and difficulty hearing low-pitched sounds. A diagnosis of otosclerosis is typically made through a hearing test and a physical examination of the ear. In some cases, imaging tests such as a CT scan or an MRI may be used to further evaluate the condition.

Treatment Options

There is no cure for otosclerosis, but there are several treatment options available to manage the condition. Hearing aids can be effective in treating mild to moderate hearing loss, while surgery may be necessary for more severe cases. The most common surgical procedure for otosclerosis is a stapedectomy, in which the fixed stapes bone is replaced with a prosthesis. In some cases, a hearing implant such as a cochlear implant may be recommended.

Prevention and Management

While there is no known way to prevent otosclerosis, there are steps that can be taken to manage the condition and prevent further hearing loss. These include avoiding exposure to loud noises, quitting smoking, and wearing ear protection when participating in noisy activities. Regular hearing tests and checkups with an audiologist or ear, nose, and throat specialist are also important for monitoring the condition and ensuring proper management.


Otosclerosis is a condition that affects the middle ear and can lead to hearing loss if left untreated. While there is no cure for otosclerosis, there are several treatment options available to manage the condition and prevent further hearing loss. If you are experiencing symptoms of otosclerosis, it is important to speak with your healthcare provider to determine the best course of treatment for your individual needs.

Causes of Otosclerosis

Otosclerosis is a condition that affects the bones in the middle ear, causing hearing loss. While the exact cause of otosclerosis is not fully understood, there are several factors that are thought to contribute to its development.

Genetic Factors

Research has shown that otosclerosis may be hereditary in some cases. Individuals with a family history of the condition are at a higher risk of developing it themselves. Genetic factors may also play a role in determining the severity of the condition and the age at which it develops.

It is important to note, however, that not all cases of otosclerosis are inherited. In fact, many individuals with the condition have no family history of it.

Environmental Factors

Exposure to certain environmental factors may also contribute to the development of otosclerosis. Loud noise, infections, and trauma to the ear can all cause damage to the delicate structures in the middle ear, leading to abnormal bone growth.

For example, individuals who work in noisy environments, such as construction sites or music venues, may be at a higher risk of developing otosclerosis. Similarly, those who have had repeated ear infections or have experienced trauma to the ear may also be more likely to develop the condition.

Hormonal Influences

Some studies have suggested that hormonal imbalances may play a role in the development of otosclerosis. Women are more likely to develop the condition, and some women report that their symptoms are worse during pregnancy or menstruation.

It is thought that the fluctuation of estrogen levels may contribute to the growth of abnormal bone tissue in the middle ear. However, more research is needed to fully understand the relationship between hormones and otosclerosis.

Viral Infections

There is also evidence to suggest that certain viral infections may contribute to the development of otosclerosis. For example, the viruses responsible for measles or mumps can cause inflammation in the middle ear, which may lead to the formation of abnormal bone tissue over time.

While viral infections are not a direct cause of otosclerosis, they may increase an individual’s risk of developing the condition.

In conclusion, otosclerosis is a complex condition with multiple potential causes. While some individuals may be more at risk due to genetic or environmental factors, others may develop the condition for unknown reasons. If you are experiencing hearing loss or other symptoms, it is important to speak with a healthcare professional for proper diagnosis and treatment.

Symptoms of Otosclerosis

Early Signs and Symptoms

The earliest signs of otosclerosis may include hearing loss and a feeling of fullness or pressure in the ear. This can cause difficulty in understanding speech, particularly in noisy environments.

Individuals with otosclerosis may also experience a sensitivity to loud noises, a condition known as hyperacusis. This can make it uncomfortable to be in loud environments such as concerts or sporting events.

Another early sign of otosclerosis is a change in the sound of your own voice. You may notice that your voice sounds different or distorted to you, even though others may not notice a difference.

Progression of Symptoms

If left untreated, otosclerosis can progress and cause more severe symptoms. These may include dizziness, vertigo, and balance problems. Some individuals may also experience a ringing or buzzing sound in the ear, known as tinnitus.

As otosclerosis progresses, it can also affect the middle ear muscles, which can cause a condition known as stapedial myoclonus. This can cause rapid, involuntary twitching of the middle ear muscles, leading to a clicking or popping sound in the ear.

Impact on Hearing

Otosclerosis can cause varying degrees of hearing loss, ranging from mild to severe. In some cases, it can lead to complete deafness in one or both ears. Hearing loss is most commonly noticed in the low-frequency range, making it difficult to hear low-pitched sounds such as men’s voices.

Individuals with otosclerosis may also experience difficulty hearing high-pitched sounds, such as birds chirping or the sound of a child’s voice.

Tinnitus and Other Related Symptoms

In addition to hearing loss, many individuals with otosclerosis experience tinnitus, a ringing or buzzing noise in the ear. This can be particularly bothersome, making it difficult to concentrate or sleep. Some individuals may also experience dizziness or vertigo, which can be triggered by changes in position or movement of the head.

It is important to note that while otosclerosis can cause significant hearing loss and related symptoms, there are effective treatments available. With proper diagnosis and management, individuals with otosclerosis can lead full and active lives.

Diagnosis of Otosclerosis

Medical History and Physical Examination

If you are experiencing symptoms of hearing loss or tinnitus, seeking medical attention is the first step towards diagnosing otosclerosis. During your appointment, your doctor will likely ask about your medical history and perform a physical examination of your ears. They may also ask you about any medications you are taking and whether you have a family history of hearing loss or ear disorders.

It’s important to be honest with your doctor about any symptoms you are experiencing, as well as any medications or supplements you are taking. Some medications can contribute to hearing loss or tinnitus, so your doctor will need to take this into consideration when making a diagnosis.

During the physical examination, your doctor will use an otoscope to look inside your ear canal and check for any abnormalities. They may also perform a hearing test to determine the extent of your hearing loss.

If your doctor suspects otosclerosis, they may refer you to an audiologist or ENT specialist for further testing.

Audiometry and Tympanometry

Two of the most common tests used to diagnose otosclerosis are audiometry and tympanometry. Audiometry is a hearing test that measures your ability to hear different frequencies of sound. During the test, you will wear headphones and listen to a series of tones at different volumes and frequencies. You will be asked to indicate when you can hear the sound.

Tympanometry measures the movement of your eardrum in response to changes in air pressure. During the test, a small probe will be placed in your ear and a tone will be played while air pressure is changed in your ear canal. This test can help to identify problems with the middle ear.

Imaging Techniques

In some cases, your doctor may recommend imaging tests such as CT scans or MRI to get a better look at the structures inside your ear. These tests can help to identify any abnormalities in the bone or tissue that may be contributing to your symptoms.

CT scans use X-rays to create detailed images of the structures inside your ear. MRI uses a magnetic field and radio waves to create images of the soft tissues in your ear. Both tests are non-invasive and painless.

Differential Diagnosis

Other conditions that can cause hearing loss or tinnitus may need to be ruled out before a diagnosis of otosclerosis can be made. These may include infections, tumors, or other disorders of the ear.

It’s important to work with your doctor to determine the underlying cause of your symptoms. Once a diagnosis is made, your doctor can recommend appropriate treatment options to help manage your symptoms and improve your quality of life.

Treatment of Otosclerosis

Although there is no cure for otosclerosis, there are several treatment options available to manage the condition and improve hearing. These may include:

  • Hearing Aids: In many cases, hearing aids can help to improve hearing loss caused by otosclerosis by amplifying sounds and making them easier to hear.
  • Surgery: In some cases, surgical intervention may be necessary to repair or replace the damaged bones in the middle ear. This may involve a procedure known as a stapedectomy, in which the stapes bone is removed and replaced with a prosthetic device.
  • Medications: Some medications such as fluoride supplements or bisphosphonates may help to slow the progression of otosclerosis by reducing the growth of abnormal bone tissue.

If you are experiencing symptoms of hearing loss or tinnitus, it is important to see your doctor to determine the underlying cause and explore treatment options. With proper management, many individuals with otosclerosis are able to maintain their hearing and quality of life.

Experts behind this article

written by

Mark Ross

Dr. Mark Ross is a Principal Investigator of the RERC on Hearing Enhancement, Professor Emeritus of Audiology, University of Connecticut and has served as Vice President of the SHHH Board of Trustees.

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