OBJECTIVE: To investigate the efficacy of hyperbaric oxygen therapy as a salvage treatment for patients with sudden sensorineural hearing loss (SSHL).MATERIALS AND METHODS: Fifteen patients affected by sudden hearing loss and treated with hyperbaric oxygen after steroid and vasodilator therapy failed constituted the study group. A control group of 30 patients who were treated with steroids and vasodilator alone was also included. Hyperbaric oxygen was administered once daily for 15 sessions at a constant pressure of 2.2 atmospheres. Pure-tone hearing thresholds were obtained for both groups before and after each treatment and frequency-specific thresholds 3 months after the end of hyperbaric oxygen therapy.RESULTS: Salvage hyperbaric oxygen therapy was performed with a mean delay of 24 days from the onset of SSHL. The overall rate of hearing improvement was higher in the study group (7/15 cases, 46.6%) compared with the control group (4/30 cases, 13.3%). The mean pure-tone hearing average thresholds after salvage treatment in the study group was 53.4 dB HL (mean gain, 12.1 dB HL), which was significantly lower than that in the control group of 67.9 dB HL (mean gain, 2.7 dB HL). Hearing recovery was found to be better at low frequencies (250-500 Hz).CONCLUSION: Hyperbaric oxygen therapy should be suggested to all patients for whom initial conventional medical treatment for SSHL has failed.