1. Department of Otolaryngology, Sugiuchi Clinic, 2-7-4 Jiyugaoka, Meguro-ku, Tokyo 152-0035, Japan
2. Kotoba no Mori—Child Development Support and After-School Daycare Facility, 2-7-4-2F Jiyugaoka, Meguro-ku, Tokyo 152-0035, Japan
3. Department of Otolaryngology, Kanto Rosai Hospital, 1-1 Kizukisumiyoshi-cho, Nakahara-ku, Kawasaki-shi 211-8510, Kanagawa, Japan
4. Department of Communication Sciences and Disorders, Faculty of Health and Welfare, Prefectural University of Hiroshima, 1-1 Gakuen-cho, Mihara-shi 723-0053, Hiroshima, Japan
5. Kawasaki City Central Rehabilitation Centre, 3-16-1 Ida, Nakahara-ku, Kawasaki-shi 211-0035, Kanagawa, Japan