Otosclerosis is a condition which affects the ossicles (tiny bones) inside the middle ear. The ossicles transmit sound vibrations from the eardrum to the cochlea (organ of hearing). Otosclerosis can affect one of both ears and typically starts between the ages of 20 to 40.
Otosclerosis is caused when abnormal bone growth sticks one of the ossicles (stapes) to other parts of the ear. This stops the stapes from moving freely
As a result, the ossicles aren’t able to pass sound waves into the inner ear as well as before, causing hearing loss. Eventually, over time, the stapes becomes so stuck it can’t move at all – this can cause severe hearing loss.
The exact cause of otosclerosis is not known. Genetic factors play a role — someone is more likely to get otosclerosis if others in their family have it.
Hearing aids are very useful if you have otosclerosis, but they won’t stop your hearing loss from getting worse. Your doctor may discuss the option of having an operation called a stapedectomy. This is where a surgeon replaces the stapes with an artificial bone made from metal or plastic. The aim of replacing this bone is to help sound waves travel through to the inner ear. This operation has a high success rate.
Find out more in our Otosclerosis factsheet.