Corresponding Author

Department of Speech and Hearing Sciences, International University of Health and Welfare, Tochigi, Japan

Correspondence should be addressed to Masako Abe, Department of Speech and Hearing Sciences, International University of Health and Welfare, 2600-1 Kitakanemaru, Otawara-City, Tochigi 324-8501, Japan (email: mabe@iuhw.ac.jp).