Otosclerosis is a medical condition that causes conductive hearing loss (involving the middle ear) and makes it harder for tiny bones in the middle ear to move. This condition is more common in women than in men. The symptoms include tinnitus, dizziness, or hearing hissing or roaring sounds. There are three small bones that connect to the ear drum to help amplify sound waves. When someone has Otosclerosis, one of the bones is unable to vibrate freely, making it harder for the tiny bones in the middle ear to move. It causes a conductive hearing loss. This condition is often treated with surgery.