This study is to build a cohort of sudden sensorineural hearing loss (SSNHL) patients. When the patient visited the Department of otolaryngology clinic for hearing loss, we can diagnose the SSNHL following the result of pure tone audiometry and the history of the patient. The cohort is a system that tracks the hearing recovery status, timing, and degree of recovery of patients who received cocktail therapy with or without high-dose steroids, vasodilators, antiviral agents, and intratympanic steroid injections, satellite ganglion block, and hyperbaric oxygen therapy.

Inclusion Criteria:

• Adult patients over 20 years of age
• A patient who visited Wonju Severance Christian Hospital, Department of Otolaryngology and was diagnosed with sudden hearing loss as it was confirmed that hearing loss of 30dBHL or more occurred within 3 days at three consecutive frequencies in a pure tone audiometry test.
• Those who have fully explained the purpose and content of the study and voluntarily agreed to the written consent

Exclusion Criteria:

• If the patients do not want to or do not fill out the consent form
• If treatment is started for sudden hearing loss, but the possibility of other inner ear diseases including Meniere's disease is suspected due to repeated hearing loss, repeated recovery, dizziness, tinnitus, etc.
• Other cases where it is judged difficult to carry out the clinical trial due to the judgment of the person in charge of the above clinical trial

Among the adults over 20yrs of age, diagnosed sudden sensorineural hearing loss at Wonju Severance Christian Hospital, Department of otolaryngology.