1. Tokyo Voice Center International University of Health and Welfare Tokyo Japan
2. Department of Otolaryngology‐Head and Neck Surgery Tohoku University Graduate School of Medicine Miyagi Japan
3. Department of Otolaryngology‐Head and Neck Surgery Jichi Medical University Tochigi Japan
4. AKASAKA Voice Health Center Tokyo Japan
5. Voice and Dizziness Clinic Futakotamagawa Otolaryngology Tokyo Japan