Otosclerosis

What is otosclerosis?

Otosclerosis is a common cause of hearing loss. It is caused by a problem with the tiny bones (ossicles) which transmit vibrations through the middle ear so we can hear sound. Usually both ears are affected in otosclerosis but sometimes only one ear is affected.

• It usually first develops between the ages of 15-35 years but sometimes develops in younger children.
• Women are affected twice as often as men.
• Pregnancy is not a cause but may make the condition worse, so symptoms are commonly first noticed during pregnancy.

Nobody actually knows why otosclerosis happens. However, what is known is that otosclerosis is not caused or worsened by listening to loud music or working in a loud environment.

Otosclerosis happens because there is abnormal bone formation in one of the tiny bones in the middle ear. It is not clear why this happens but it is likely to be caused by a combination of various factors:

• Hereditary (genetic) factors.
• Complications from having had a virus.
• Possible effect of low fluoride levels.

Otosclerosis symptoms

• Hearing loss
• Speaking softly
• Hearing better in noisy surroundings
• Hearing sounds from within your body
• Dizziness and balance problems

Hearing loss

Hearing loss is the main symptom of otosclerosis. The hearing loss may remain mild but commonly it gradually becomes worse. It usually affects both ears, but not always. In some people the hearing loss stays mild for a number of years before getting worse. In others the hearing loss quickly becomes worse. Without treatment, in time, the affected ears often become totally deaf.

The hearing loss is usually of lower sounds, whereas age-related hearing loss has more effect on higher-pitched sounds.

Speaking softly

If you have otosclerosis, you may speak unusually quietly. The effect of otosclerosis on your ears is to make your own voice sound loud to you.

Hearing better in noisy surroundings

Paracusis is also common. If you have this, you can hear better when there is a lot of background noise. For example, you seem to hear better when talking to someone in a pub or a café that is full of other people. This may be because other people raise their voices in noisy places.

Hearing sounds from within your body

Tinnitus is an abnormal noise which you hear but which seems not to come from outside your ear. It occurs in about 4 in 5 people with otosclerosis. Noises heard include ringing, whistles, roaring, machine-type noises, etc. Tinnitus tends to worsen as hearing loss worsens.

Dizziness and balance problems

Vertigo is a condition where problems with dizziness and balance are experienced. This condition develops in some people with otosclerosis, although it is less common. It occurs when the balance mechanism in the inner ear (the semicircular canals) is affected.