The probability of recovery from idiopathic sudden hearing loss depends on many factors, including patient age, presence of vertigo, audiogram type at diagnosis, and electronystagmographic test results. The authors present a model for calculating the probability of patient recovery based on the combined effects of risk factors determined for these variables. Data collected from 123 patients with "profound" or "moderate" sudden hearing losses are used to illustrate the model. Interrelationships among the prognostic factors and their relative importances in predicting hearing recovery are discussed.