Abstract
48 cases with sensori-neural hearing loss were observed for 6 month or more audiometrically. The characteristic variations of hearing loss were able to observe, according to the kinds of the hearing loss. Little changes were observed in 32 cases with sesori-neural hearing loss. On the other hand, the shift to recovery was shown in cases of acoustic truma and acoustic neuritis. The fluctuation of hearing loss was shown in cases of Meniere's disease and congenital labyrinthine lues. The progression of hearing loss was shown in eleven cases of 5 familial deafness, each one of oto-toxic deafness, Lermoyez's syndrome, meningitis, multiple sclerosis, brain-stem tumor and etiology unknown. They were classified to 3 types, as a function of time course of the progression: gradual, sudden and rapid progressive type. Many cases among them showed gradual progression of hearing loss, and other types were uncommon, especially rapid progressive type was observed in cases of multiple sclerosis and brain-stem tumor.
