A Comparative Study of Vocal Fold Vibratory Behaviors Shown in the Phonation of the /i/ Vowel between Persons who Stutter and Persons with Muscle Tension Dysphonia Using High-Speed Digital Imaging

초고속 성대촬영기(High-Speed Digital Imaging)를 이용한 말더듬인과 근 긴장성 발성장애인의 /이/모음 발성 시 성대 진동 양상에 관한 비교 연구

The purpose of this study was to use high-speed digital imaging (HSDI) to compare vocal vibratory behaviors of persons who stutter (PWS) and persons with muscle tension dysphonia (PMTD) for uttering the /i/ vowel in a bid to identify the characteristics of vocal fold vibratory behaviors of PWS. This study surveyed seven developmental PWSs and seven PMTDs. The findings of the study indicated the following: first, regarding the two groups' vocal fold vibratory behaviors, of seven PWSs, three were found to be close vocal tract (VC) and four were found to be combination vocal tract (VCB). Of the seven PMTDs, one was found to be VC, and the other six were found to be VCB. These results indicate that a voiceprint which is different from the open vocal tract (VO) found in normal groups in research conducted by Jung, et al. (2008b) appeared in both groups of this study. Even between the two groups, there is a difference in the voiceprint before vocalization. Second, a VKG analysis was conducted to identify the two groups' vocal cord contact quotient. As a result, the PWS group's vocal cord contact quotient changed gradually from an irregular one at the initial vocalization stage to a regular one. The PMTD group continued the tension at the initial vocalization. Putting together all of these results, there is a difference in vocal fold vibratory behaviors between PWSs and PMTDs when they speak. Thus, there was a difference in muscular tension between the two groups.