Otosclerosis is classified into two types. Histological otosclerosis refers to the condition where ossification (sclerosis) of the stapes bone has begun, but the patient experiences no symptoms. Clinical otosclerosis, on the other hand, describes cases where patients with stapes ossification also begin to experience symptoms. The prevalence of histological otosclerosis is reported as 7% in men and 19% in women. Among individuals with histological otosclerosis, approximately 12% are diagnosed with clinical otosclerosis.