1. Department of Otolaryngology, ST. Vincent's Hospital, Catholic University, Suwaon 442-723, Korea.
2. Department of Speech-language Pathology, Chungnam National University, Daejeon 305-764, Korea.
3. Graduate School of Complementary and Alternative Medicine, Wonkwang University, Iksan 570-749, Korea.
4. Department of Rehabilitation Medicine, Yuseong Wellness Hospital, Daejeon 305-301, Korea.
5. Department of Linguistics, Chungnam National University, Daejeon 305-764, Korea.