표 4. | Table 4. 조음 변동성 평가를 위한 음향 자질별 최소변별치 기준 | Just noticeable difference (JND) thresholds for articulatory variability

Feature	JND-based threshold
VarcoV	LM≥30.0%
Formant trajectory length	CV ratio≥1.2
Formant dispersion	SD ratio≥1.5
F1/F2 ratio	|Δ(F1/F2)|≥10%
F2/F3 ratio	|Δ(F2/F3)|≥10%

LM, learner mean.