o·to·scle·ro·sis 
(ō′tō-sklə-rōsĭs)
(ō′tō-sklə-rōsĭs)n.
A disease of the ear in which the movement of the stapes within the oval window becomes impeded by abnormal deposits of spongy bone, leading to a progressive loss of hearing.
o′to·scle·rotic (-rŏtĭk) adj.