Clinical study of sudden deafness with special reference to onset.

In a comparative study, patients with sudden deafness were classified into four groups according to type of onset. The results showed that those who noticed deafness occurring when awakening had a better prognosis than others, particularly those who found themselves already suffering from deafness on awakening. These findings suggest that among patients who have deafness on awaking, the disorder may not be sudden deafness in sensu strictu.