1. Sub-Committee on Sudden Sensorineural Hearing Loss, Quality Control Committee, Korean Otologic Society, Seoul, Korea.
2. Department of Otorhinolaryngology Head & Neck Surgery, Gangneung Asan Hospital, Gangneung, Korea.
3. Department of Otorhinolaryngology Head & Neck Surgery, Seoul National University Boramae Medical Center, Seoul, Korea.
4. Department of Otorhinolaryngology Head & Neck Surgery, The Catholic University of Korea College of Medicine, Seoul St. Mary's Hospital, Seoul, Korea.
5. Department of Otorhinolaryngology Head & Neck Surgery, Dankook University College of Medicine, Cheonan, Korea.
6. Department of Otorhinolaryngology Head & Neck Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
7. Soree Ear Clinic, Seoul, Korea.
8. Department of Otorhinolaryngology Head & Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.