표 3. | Table 3. 등급별 모음의 평균 발화 길이와 평균 비율 | Mean length of each vowel and the mean ratio of the vowels

Proficiency level	Vowel length in an article (ms)	Vowel length in a noun (ms)	Ratio
Native speakers	55.88	165.17	2.955
ADV(최상위)	67.69	154.73	2.453
INT-High(중상위)	148.48	187.24	1.26
INT-Low(중하위)	197.73	204.58	1.034
NOV(최하위)	235.38	201.77	0.857

ms: millisecond