[1] Kurume Univ, Sch Med, Dept Otolaryngol Head & Neck Surg, Kurume, Fukuoka, Japan
[2] Kochi Univ, Dept Otolaryngol, Sch Med, Kochi, Japan
[3] Kurashiki Cent Hosp, Kurashiki, Okayama, Japan
[4] Kawasaki Med Sch, Dept Otolaryngol, Kurashiki, Okayama, Japan
[5] Fukushima Med Univ, Sch Med, Dept Otolaryngol, Fukushima, Japan
[6] Tohoku Bunka Gakuen Univ, Fac Med Sci & Welf, Dept Rehabil, Speech Pathol & Hearing Course, Sendai, Miyagi, Japan
[7] Kumada Clin, Tokyo, Japan
[8] Nihon Univ, Sch Med, Dept Otorhinolaryngol Head & Neck Surg, Tokyo, Japan
[9] Univ Hokkaido, Hlth Sci, Sch Rehabil Sci, Sapporo, Hokkaido, Japan
[10] Kyorin Univ, Sch Med, Dept Otolaryngol Head & Neck Surg, Mitaka, Tokyo, Japan
[11] Prefectural Univ Hiroshima, Fac Hlth & Welf, Dept Commun Sci & Disorders, Hiroshima, Japan
[12] Kyoto Univ, Grad Sch Med, Dept Otolaryngol Head & Neck Surg, Kyoto, Japan
[13] Yamahoshi Ear Nose & Throat Clin, Tokyo, Japan
[14] Natl Hosp Org Tokyo Med Ctr, Natl Inst Sensory Organs, Dept Artificial Organs & Med Creat, Tokyo, Japan
[15] Natl Def Med Coll, Dept Otolaryngol Head & Neck Surg, Tokorozawa, Saitama, Japan