구개열 환자 성문 파열음의 음향학적 특징 = Acoustic characteristics of glottal stop in individuals with cleft palate

다국어 초록 (Multilingual Abstract)

Glottal stop is one of the characteristics of cleft palate speech and is similar to the glottalized stop sound of the Korean language. Glottal stop is defined as a plosive produced when the glottis is completely stopped, exhalation is interrupted, subglottal air pressure is heightened, and vocal folds are abducted. It is sometimes called reinforcing glottal stop. When glottal stop is produced, the laryngeal type is divided into Type 1 and Type 2. Type 1 is a plosive noise produced when the true vocal fold is adducted prior to voice onset (VO) and begins to vibrate and only the ventricular fold is abducted. Type 2 is a plosive produced when the true vocal fold and ventricular fold are adducted prior to voice onset and immediately abducted. This study aims to understand the acoustic characteristics of glottal stop in individual with cleft palate. 10 individuals with cleft palate and 16 controls participated, and the individuals with cleft palate were divided into those substituted glottal stop and those not substituted. The experiment was conducted using the CSL 4500, Nasometer Ⅱ 6200. The assessment sample included bilabial sound, alveolar sound, velar sound from each lenis sound, aspirated sound, and glottalized stop sound. The assessment sample analyzed included the slope of energy prior to voice onset, VOT, VD, TD, and Hold on the spectrogram and nasalance slope such as closing phase (slope 1), closed phase (slope 2), and opening phase (slope 3) on the nasalance graph.
The findings are listed in the following:
First, VOT of the group with substituted glottal stop is the shortest and statistically significant. VOT of the group with no substituted glottal stop is longer than that of the control group. As for all the stop sounds, the slope of energy of the group with substituted glottal stop is bigger than that of the control group and statistically significant.
Second, in the closing phase, the nasalance slope of the group with substituted glottal stop and the group with no substituted glottal stop is larger than that of the control group and statistically significant. Moreover, the group with substituted glottal stop has a higher nasalance slope compared to the group without substituted glottal stop and is statistically significant for alveolar sound /t＾(h)i/ and velar sound /k＾(h)i/.
Third, at all phases including the closing phase, closed phase, and opening phase, the group with substituted glottal stop and the one without substituted glottal stop have higher nasalance compared to the control group and are statistically significant. However, when the group with substituted glottal stop is compared to the group with no substituted glottal stop, there is statistical significance only at the opening phase of /p＾(h)a/ and /t＾(h)i/.
Finally, when correlation analysis is conducted of the energy slope on the spectrogram and nasalance slope at the closing phase (slope 1), the correlation coefficient is found to be 0.766, which implies a very strong correlation.

목차 (Table of Contents)

• Ⅰ. 서론 = 4
• Ⅱ. 연구방법 = 6
• 1. 연구대상 = 6
• 2. 음성표본 = 6
• 3. 실험장비 = 6
• 3.1. 분석항목 = 7
• 3.1.1. CSL = 7
• 3.1.2. Nasometer = 7
• 4. 통계분석 = 8
• Ⅲ. 연구결과 = 9
• 1. 스펙트로그램 분석 = 9
• 1.1. VOT = 9
• 1.2. VD = 10
• 1.3. TD = 11
• 1.4. Hold = 11
• 1.5. 음성 강도의 경사도 = 12
• 2. 비음도 분석 = 12
• 2.1. 비음도 = 13
• 2.2. 비음 경사도 = 13
• 3. 성문 파열음(Glottal stop)과 경음(Glottalized stop) = 14
• 3.1. 스펙트로그램 분석 = 15
• 3.2. 비음도 분석 = 15
• 3.2.1. 비음도 = 15
• 3.2.2. 비음 경사도 = 16
• Ⅳ. 고찰 = 17
• Ⅴ. 결론 = 20
• 참고문헌 = 22