1. Department of Otorhinolaryngology, Head and Neck Surgery, Nippon Medical School, Tokyo 113-8603, Japan
2. Department of Hearing Implant Sciences, Shinshu University School of Medicine, 3-1-1, Asahi, Matsumoto City 390-8621, Japan
3. Department of Otorhinolaryngology, Hirosaki University Graduate School of Medicine, Hirosaki 036-8560, Japan
4. Department of Otolaryngology-Head and Neck Surgery, Tohoku University School of Medicine, Sendai 980-8575, Japan
5. Department of Otolaryngology, Tohoku Rosai Hospital, Sendai 981-8563, Japan
6. Department of Otorhinolaryngology, Toranomon Hospital, Tokyo 105-8470, Japan
7. Department of Otolaryngology, Kamio Memorial Hospital, Tokyo 101-0063, Japan
8. Akasaka Toranomon Clinic, Tokyo 107-0052, Japan
9. Department of Otorhinolaryngology, International University of Health and Welfare, Mita Hospital, Tokyo 108-8329, Japan
10. Department of Otorhinolaryngology, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
11. Department of Otorhinolaryngology-Head and Neck Surgery, Yokohama City University School of Medicine, Yokohama 236-0004, Japan
12. Department of Otolaryngology, Yokohama City University Medical Center, Yokohama 232-0024, Japan
13. Department of Otolaryngology, Gifu University Graduate School of Medicine, Gifu City 501-1194, Japan