OBJECTIVE To evaluate the influence of the treatment delay for sudden sensorineural hearing loss (SSHL) on the final hearing recovery and the prognostic value of the audiometric shapes and the hearing recovery at the end of treatment. METHODS Prospective study including 321 patients admitted in the emergency care center for a recent idiopathic SSHL. Classification according to the audiometric shape in 5 types. All patients received steroids (1 mg/kg per day) and, in case of ascending shape, steroids and mannitol during 6 days. Hearing recovery was evaluated according to the following parameters: 1) hearing recovery (initial PTA-PTA at D6 or D30); 2) incidence of hearing recovery (initial PTA-PTA at D6 or D30)/initial PTA x 100%). RESULTS Whatever the audiometric type, delay in initiating treatment did not have any influence on the final outcome. Audiometric classification had a good prognostic value, since the ascending shape had a better hearing recovery than descending shape or the sub or total anacusis. Hearing recovery at D6 is a prognostic factor on the final outcome. CONCLUSIONS Idiopathic SSHL cannot be considered, nowadays, as an otologic emergency.