Otosclerosis is an abnormality of the middle ear that can cause gradual hearing loss. It is believed to have a genetic component, although the exact pattern of heredity can be unpredictable and therefore difficult to trace. About.5% of the US population is believed to suffer from otosclerosis, which is more common among Caucasians than any other race. Symptoms usually begin in middle age, but can begin much sooner.

Hearing, the Middle Ear, and Otosclerosis

In order to understand how otosclerosis affects its sufferers, it is important to understand how the human ear functions. Doctors divided the ear into three different areas:

• Outer ear - This is the visible "shell" of the ear (known as the pinna or concha) as well as the opening of the ear canal. Sound waves are "funneled" by the pinna and travel into the canal.
  
  
• Middle ear - As sound waves travel through the canal, they enter the ear drum, which is a membrane stretched across the canal. Sound makes the eardrum vibrate, which converts the sound into kinetic energy. This energy then travels through the middle ear, which consists of three small bones (ossicles) called the hammer, anvil, and stirrup.
  
  
• Inner ear - The last ossicle (the stirrup) is connected to a small sensory organ called the cochlea. This organ is snail-shaped and filled with fluid; its interior is lined with small auditory nerves known as hair cells. As the stapes vibrates from sound waves, the fluid in the cochlea does the same, causing the hair cells to move. This movement stimulates the cells, allowing them to convert the kinetic energy into electrochemical signals that are sent to the brain. In the brain, these signals are finally converted into the perception of sound.
  

Hearing loss is generally divided into one of two types: conductive and sensorineural. Conductive hearing loss results when something prevents sound from traveling through the middle ear correctly. Sensorineural hearing loss occurs when the hair cells of the cochlea are damaged, preventing them from responding correctly to stimuli.

Otosclerosis is an example of conductive hearing loss. It causes lesions to develop on the stirrup ossicle. These are eventually covered by scar tissue, which can build up over time, eventually causing the stirrup to partially fuse onto the cochlea. Of course, this prevents the bone from vibrating correctly, which impairs the quality of messages being sent to the cochlea.

Treatment for Otosclerosis

Unfortunately, there is no consistent cure for otosclerosis. Its sufferers will begin to gradually lose their low frequency hearing; some will also begin to lose high frequency hearing over time. Fortunately, hearing aids can help them compensate for this loss. In addition, a surgical procedure that involves replacing the stirrup with a small prosthesis has helped some patients regain their hearing.

To learn more about the variety of hearing aids available today, contact HearingPlanet.