Q: Although I am only 29, the hearing in my right ear has been getting slowly worse over the past two years. This problem is particularly worrisome because my father became deaf in both ears when he was in his late 50s.

A: My advice is that you have your hearing tested, because it sounds like your concern is reasonable and that you are in the early stages of a hearing disorder that runs in families. Although several diseases that cause hearing problems are familial, the most common is otosclerosis, estimated to affect one out of every 200 people, and is especially prevalent among Caucasians and women.

Otosclerosis is caused by an abnormal growth of bone within the middle ear that leads to a gradual loss of hearing. The overgrowth of bone interferes with movement of the stapes, one of the three small bones in the middle ear that transmit soundwaves to the inner ear where they are converted to electrical signals sent to the brain. Otosclerosis may involve only one ear, but more often both ears, either at the same time or in succession. Hearing loss begins before age 30 and usually progresses over a period of 10 to 15 years and often results in total deafness. Symptoms of otosclerosis in clude the ability to hear conversations better when there is more background noise, ringing in the ears and dizziness.

While there is no way to prevent or cure otosclerosis, a surgical procedure called a stapedectomy is quite successful in providing significant improvement in the hearing of most people. The operation involves removal of the immobilized stapes and replacing it with a tiny artificial substitute. If there is hearing loss in both ears, stapedectomy is carried out in one ear at a time because of a small risk of total deafness after the operation. Hearing aids can be helpful prior to, or instead of, surgery, and may be needed to augment hearing after a stapedectomy.

Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine.