How does a stapedectomy improve hearing in people with otosclerosis?

In otosclerosis, abnormal spongy bone growth immobilizes the stapes—the middle ear bone that acts as a piston to conduct sound energy into the inner ear. This fixation prevents the normal transmission of sound vibrations, resulting in conductive hearing loss.123

A stapedectomy improves hearing by surgically removing the immobilized, encrusted stapes and replacing it with a prosthetic substitute made of plastic or wire. By restoring the mechanical link between the middle ear and the inner ear, this procedure allows sound vibrations to once again reach the cochlear fluids effectively. This restoration of the middle ear's function as an impedance-matching transformer enables the patient to approach normal hearing levels, provided the inner ear's sensory cells remain healthy.1234