Analysis of hearing improvement in patients with severe to profound sudden sensorineural hearing loss according to the level of pure tone hearing threshold

Patients with profound sudden sensorineural hearing loss (SSNHL) have a poor prognosis regardless of the type of treatment they receive. However, there is evidence that a proportion of patients with profound hearing loss may exhibit variable degrees of recovery, and this has yet to be specifically investigated. Here, we report a comparison of levels of hearing improvement in patients stratified according to their level of hearing threshold before treatment. We divided patients with severe to profound SSNHL into three groups: patients with an initial hearing threshold of 80–89 dB (n = 18), 90–99 dB (n = 16), and ≥100 dB (n = 34). We compared improvements in hearing threshold at different frequencies and recovery rates between the three groups. No significant differences were observed in hearing threshold improvements at different frequencies in the three groups after treatment. However, in the group with an initial hearing threshold of ≥100 dB, significantly less complete and partial recoveries occurred compared to those in the 80–89 or 90–99 dB groups. Our results suggest that initial hearing threshold in excess of 100 dB alters the likelihood of satisfactory recovery in patients with severe to profound SSNHL.