Otosclerosis: Types, Symptoms, Causes, Risks, Complications, Diagnosis, Treatment and Outlook



Hearing loss is a condition caused by many factors. One type of hearing loss, otosclerosis is the disease of the bones in the middle and inner ear. The ossicles or bones inside the ears become knit or compiled together into an immovable mass and as a result, they can’t transmit sound properly.

Normal Function Of The Ear

The ear has three main parts – external, middle and inner ear. Each part of the ear performs a vital function in the hearing process. Sound waves pass through the ear canal and vibrate the ear drum. The ear drum works by separating the middle and inner ear from the external ear.

The incoming sound waves make the eardrum vibrate, and these vibrations go to three tiny bones in the middle ear called the incus (anvil), malleus (hammer) and stapes(stirrup).

There are three tiny bones or ossicles inside the ear that aids in the hearing process. The hearing loss type depends on which part of the ear is affected. For instance, there is some problem in the external ear, it’s termed as a conductive hearing loss while if the problem is in the inner ear, the problem is a sensorineural hearing loss. Sensorineural hearing loss is harder to treat and prevent because the nerve is the one affected. The nerve is the one that transmits the messages to the brain, for it to interpret the sounds you are hearing.

In otosclerosis, however, the tiny bones or ossicles clamp together and either softens or hardens, making them unable to transmit sound.

Only 0.3 percent of the population has otosclerosis and it affects people between the ages of 11 and 30 years old. This stage is called otospongiosis. During this time, there might be still no hearing loss. However, if this condition is not treated promptly, it may lead to permanent hearing loss and gradual hardening and damage of the small bones inside the ears.

2Three Types of Otosclerosis

Conductive Type

This happens when otosclerosis involves the tiny bones of the middle ear. This is reversible and treatable by a hearing aid and surgical procedure.

Sensory Hearing Loss Type

This happens when it involves the bones which surround the inner ear called optic capsule. This is more severe and could not be repaired by surgery. Hearing aids could provide little comfort and hearing but they may also be ineffective.

Mixed Type

If the condition affects both the small bones and the cochlea, it’s considered a mixed type, which is more serious and hard to treat.

Did you know that the famous composer Beethoven suffered from otosclerosis? He suffered from the illness making him unable to hear his last compositions.


Just like any other hearing loss problems, the three main symptoms include:

  • Hearing loss that gets worse in time
  • Vertigo or dizziness (you feel like your surrounding is spinning)
  • Ringing in the ears (tinnitus) – sometimes this comes in various sounds – tapping, buzzing, knocking,etc.)

Other symptoms include:

  • Difficulty hearing low and deep sounds
  • Difficulty hearing whispers
  • Speaking quietly because the voice sounds loud to you
  • Easier to hear when there’s background noise


Otosclerosis happens when one of the tiny bones in the middle ear, the stapes or stirrup, becomes stuck in place. As a result, the bone can’t vibrate and sound can’t travel to the inner ear. Hearing loss may become evident.

Though the exact reason for this occurrence remains unclear for scientists, some of them believe that a previous measles infection could affect these tiny bones. Other possible causes are autoimmune diseases and stress fractures to these tiny bones.

Some say that this condition is hereditary and can be passed down through families. This is the most common cause of hearing the loss in younger adults and begins in early to middle adulthood. However, women are at a higher risk than men to have otosclerosis.

Some scientists believe that otosclerosis occurs only in human temporal bones. Thus, it can be considered as a disorder of new bone formation.

5Risk Factors

There are some factors that predispose a person to otosclerosis which include:

Family History

Otosclerosis tend to occur in families and this suggests that some people are genetically predisposed to the disorder.


 Women are more likely to develop the otoscle or a spongy tiny bone


Some women who become pregnant develop otosclerosis


Caucasians or white people are prone to having otosclerosis.

Measles Virus

Some scientists say that viruses like the measles virus predispose the person to have otosclerosis

Osteogenesis imperfecta

This is a genetic disorder wherein a person has abnormally brittle bones. This could increase the risk of developing otosclerosis. People with the gene that predisposes them to this condition is similar to the one that causes otosclerosis. These genes are transmitted in the autosomal dominant way.


Just like any other hearing loss problems, there are accompanying complications and long-term effects of otosclerosis such as:

  • Complete hearing loss or deafness
  • Nerve damage
  • Significant loss of about 50 – 60 dB in hearing
  • Social and emotional effect – inability to properly communicate with others
  • Difficulties at work, school, and home
  • Depression, anxiety, and frustration
  • Financial burden

Moreover, the surgery has accompanying complications too:

  • Total unilateral sensorineural hearing loss in 1 – 2 percent of cases
  • Facial nerve injury
  • Perforation of the eardrum, which is easy to repair
  • Infection and pain
  • Blood clot
  • Disturbance in taste sensation
  • Tinnitus may worsen


There are two ways to diagnose otosclerosis including:

Hearing tests

Hearing tests such as audiometry, audiology, tuning fork tests and others may help determine the severity of hearing loss.

The doctor conducts these test to determine the extent of hearing loss and to determine if the problem could be managed through hearing aids or a surgery is needed.

CT Scan and other imaging tests

Imaging tests can help detect the problem inside the ears and determine the exact cause of hearing loss.

Aside from these diagnostic techniques, a complete physical examination and medical history taking are also important in diagnosing otosclerosis. The doctor may ask questions about your family history, previous history of illness like infections, trauma to the head and other possible causes of hearing loss.


There are three main treatment options for otosclerosis:


There is no local treatment to the ear itself of any medication to treat hearing loss in people in otosclerosis. However, medications can be useful in preventing further hearing loss.

However, today, the only prescribed medical treatment for otosclerosis has been sodium fluoride, a dietary supplement. There are many studies that have shown the benefits of this supplement in the hardening of the bones as it is used for the teeth. However, it is still gaining approval from health experts. Remember, all medications and treatments should be prescribed by a licensed doctor. Do not self-medicate because this might cause further damage to the ears.

Moreover, since pregnant women are more susceptible to otosclerosis and it worsens during pregnancy, many scientists believe that estrogen has something to do with the development of the condition. The avoidance of estrogen or estrogen blockers could help a person with otosclerosis. However, this has not been fully studied yet.


A surgery on the tiny bone stapes is usually recommended for patients with otosclerosis. The surgery is just minor and requires minimal hospitalization. In fact, about 90 percent of those people who underwent stapedectomies or repair of the stapes bone had their hearing back permanently.

Hearing Aids

 Just like any other hearing loss problems, patients with otosclerosis benefit from using hearing aids. Some patients who can’t undergo surgeries use hearing aids because the condition does not cause total hearing loss.


If left untreated, otosclerosis could lead to partial or complete hearing loss. This could greatly impact the life of the patient because it could affect one’s communication with others and social, emotional and physical health.

However, surgically treated otosclerosis has a good prognosis in a majority of the cases. In fact, the rate of hearing loss and deterioration after surgery has been slowed and does not exceed that due to presbyacusis or old age hearing loss.

Without treatment, the condition worsens. Surgery is beneficial but you can reduce the complications of the surgery:

  • Avoid blowing your nose for 2 to 3 weeks after the surgery
  • Avoid bending, straining or lifting heavy objects because this might trigger dizziness
  • Do not go to crowded places and avoid people with respiratory illness, since the eustachian tube connects the ears to the nose, respiratory illness may increase the pressure inside the ears.
  • Avoid loud noises or sudden pressure changes like riding an airplane, scuba diving or driving up the mountains.

For otosclerosis that can’t be treated with surgery, supportive measures are needed to cope with a permanent hearing loss like developing skills in sign language, using hearing aids to aid in hearing and using the good ear for hearing.

Moreover, emotional and social support are important to reduce feelings of frustrations, depression, and anxiety among patients diagnosed with otosclerosis, just like any other hearing loss problems.