Abstract
Audiograms in the initial stage and the fixed stage of sudden deafness were analyzed in 79 cases using the following 5 criteria; i) the onset is sudden and time of onset definite, ii) hearing loss at 1 kH is more than 35 dB, iii) the course of hearing recovery is clear, iv) unaffected ear has normal hearing, and v) the first examination and treatment is within 15 days after onset. Consequently, at least in cases receiving treatment within 6-15 days after onset, it was considered that the prognosis of hearing recovery could be established rather than the pattern of hearing loss than by the period of treatment after onset.