Patterns of hearing recovery in idiopathic sudden sensorineural hearing loss

Patterns of hearing recovery in idiopathic sudden sensorineural hearing loss (ISSNHL) during the initial stage of treatment were examined in 51 patients who showed significant recovery. By plotting average hearing threshold level or degree of average hearing improvement against number of days after the first examination, a pattern of recovery was seen for each patient, and the superimposed patterns of hearing recovery were examined as a whole and in groups. The results indicated that most patients showed either initial rapid recovery reaching a plateau or a very gradual and slow recovery. In a small number of patients, the pattern of rapid recovery appeared somewhat delayed. Further analysis by grouping the patients revealed that initial rapid recovery was frequently observed in the groups which showed smaller degree of hearing loss at the first examination, greater degree of hearing improvement overall, and smaller degree of hearing loss once stable. The results of this study appear to indicate that patterns of recovery at the initial stage of ISSNHL reflect the prognosis to a certain degree.