Is otosclerosis hardening of the bony tissue?

Otosclerosis is a condition in which the bony tissue surrounding the middle ear bones (malleus, incus, and stapes) thickens and becomes harder. This abnormal bone growth can fix the stapes bone in place, preventing it from vibrating properly and transmitting sound waves to the inner ear. As a result, hearing loss occurs.

Otosclerosis primarily affects the stapes bone, causing conductive hearing loss. In some cases, it can also affect the cochlea (the sound-receiving organ of the inner ear), resulting in sensorineural hearing loss.