Assessment of prognosis in sudden deafness.

We investigated the usefulness of three-dimensional audiograms in assessing prognosis during the early phase in 116 patients with sudden deafness. The initiation time of improvement in middle-frequency hearing at 15 dB or more was valuable in assessing prognosis in patients with deafness and scale-out types of hearing loss. Improvement within 13 days in patients with the deafness type, and within 17 days in those with the scale-out type, was correlated with a high incidence of marked improvement or complete recovery. Patients with an initial mean hearing level below 80 dB, or in whom the glycerol test and electrocochleography results suggested the presence of endolymphatic hydrops, had a good hearing outcome. Patients without tinnitus showed an unfavorable hearing outcome.