1. Departments of Otolaryngology–Head and Neck Surgery, Tokyo, Japan.
2. University of Texas Southwestern Medical Center, Dallas, Texas, Department of Otolaryngology, International Medical Center of Japan, Tokyo, Japan.
3. Department of Otorhinolaryngology–Head and Neck Surgery, University of Tokyo, Tokyo, Japan.
4. Department of Communication Disorders, Health Sciences University of Hokkaido, Hokkaido, Japan.
5. Biomedical Engineering, Tokyo, Japan.