It is still difficult to evaluate the efficacy of treatment of sudden deafness. Effective methods of therapy have been reported in some studies and other studies have reported spontaneous recovery. In the present study, we assessed the correlation between hearing recovery and various parameters measured during recovery. We used three parameters: hearing gain, relative hearing gain, and recovery rate. We found that the recovery rate during recovery and the parameters measured on the 7th treatment day demonstrated the greatest correlation. The recovery rate on the 7th day of treatment was found to be useful for predicting the final hearing recovery. Comparison of the recovery rate on the 7th day of treatment may be useful for the evaluation of the efficacy of treatment of sudden deafness.