Otosclerosis: Symptoms, Causes, Diagnosis and Treatment

01What

What happens in otosclerosis?

The middle ear contains three tiny bones: the malleus, incus and stapes. They pass vibrations from the eardrum to the inner ear, where they are converted into nerve signals. In otosclerosis, spongy new bone forms around the base of the stapes and gradually fixes it in place, so less sound reaches the inner ear. In some people, the process also affects the cochlea, the hearing organ itself, causing sensorineural hearing loss. The NHS explains that otosclerosis usually develops slowly over years.

02Symptoms

Symptoms

• Gradual hearing loss, often first noticed in one ear and later in both.
• Difficulty hearing low-pitched sounds and quiet speech.
• Tinnitus: ringing, buzzing or hissing in the ear.
• Hearing speech better in noisy places, a feature sometimes reported in otosclerosis.
• Hearing your own voice or chewing more loudly.
• Occasional dizziness or balance problems.
• Symptoms often start between the ages of 20 and 40.

03Who

Who gets otosclerosis?

• It is more common in women than men.
• It often runs in families; many people have a relative with hearing loss.
• It is more common in people of European descent.
• Hearing loss may progress more quickly during pregnancy.
• It usually affects both ears, though often unevenly.

04Causes

What causes it?

The exact cause is not fully understood. A review of the etiology of otosclerosis described it as a complex condition with several contributing factors: genetic predisposition, with several genes identified; possible persistent measles virus infection in the bone of the ear; hormonal influences, which may explain why pregnancy can worsen it; and immune and inflammatory processes. It is not caused by noise exposure or ear infections.

05Diagnosis

How it is diagnosed

• Ear examination: the eardrum usually looks normal.
• Tuning fork tests: can suggest conductive hearing loss.
• Audiogram (hearing test): shows the type and degree of hearing loss.
• Tympanometry: usually normal, helping distinguish otosclerosis from fluid in the ear.
• Acoustic reflex testing: reflexes are often absent.
• CT scan: sometimes used to look at the bone around the inner ear.

06Aids

Hearing aids

Hearing aids amplify sound and work well for many people with otosclerosis, because the inner ear often still functions normally. They avoid the risks of surgery and can be used at any stage. Modern hearing aids are small, adjustable and can be connected to phones and other devices. Some people use hearing aids while deciding about surgery. Our guide to hearing aids for tinnitus describes how they can also help with ringing.

07Surgery

Stapes surgery

Stapedectomy or stapedotomy involves removing all or part of the fixed stapes and replacing it with a tiny prosthesis, allowing sound to pass to the inner ear again. It is usually done through the ear canal, often under general anaesthetic, and many people go home the same or next day. Most people have a significant improvement in hearing. Risks include temporary dizziness, taste changes, tinnitus and, rarely, worsening or complete loss of hearing in the operated ear. Surgery is usually performed on one ear at a time, starting with the worse ear.

08Other

Other treatments and support

• Sodium fluoride has been used to try to slow progression, but evidence is limited and it is not widely recommended.
• Tinnitus management: sound therapy and counselling; see tinnitus treatment.
• Assistive devices: amplified phones, TV listeners and alerting devices.
• Communication tactics: facing people, reducing background noise, asking others to speak clearly.
• Cochlear implants may be considered in rare cases of severe sensorineural involvement.

09Pregnancy

Otosclerosis and pregnancy

Some women notice their hearing gets worse during or after pregnancy. The reasons are not fully understood but may involve hormonal changes. Women with otosclerosis who are pregnant or planning pregnancy can discuss monitoring with their ear specialist. Pregnancy is not a reason to avoid treatment, but surgery is usually planned for another time.

10Other causes

Other causes of gradual hearing loss

• Age-related hearing loss, which affects high pitches first.
• Noise-induced hearing loss.
• Earwax build-up.
• Fluid behind the eardrum.
• Ménière’s disease.
• Acoustic neuroma, a rare cause of one-sided hearing loss.
• If hearing seems muffled, see muffled hearing.

11Living

Living with otosclerosis

• Have regular hearing tests to monitor changes.
• Tell family, friends and colleagues how they can help you hear better.
• Use captions on TV and video calls.
• Choose quieter places to meet and sit with your back to the wall in restaurants.
• Protect your hearing from loud noise.
• Ask about workplace adjustments if hearing affects your job.

12Recovery

Recovery after stapes surgery

After stapes surgery, hearing often improves within weeks as swelling settles, although it can seem muffled at first because of packing in the ear canal. People are usually advised to avoid heavy lifting, nose blowing, flying and getting water in the ear for a few weeks, following their surgeon’s instructions. Mild dizziness or a changed sense of taste may occur temporarily. A follow-up hearing test checks the result.

13Summary

Key points to remember

• Otosclerosis fixes the stapes bone and causes gradual hearing loss.
• It often starts in early adulthood and runs in families.
• Hearing aids and stapes surgery are both effective.
• Sudden hearing loss needs urgent assessment.