Cross-cultural adaptation and validation of the intelligibility in context scale for Azerbaijani Turkish-speaking children

This study aimed to cross-culturally adapt the Intelligibility in Context Scale (ICS) into Azerbaijani Turkish (ICS-AZ) and evaluate its psychometric properties. Following forward-backward translation and expert review (n = 13 SLPs), the ICS-AZ was completed by parents of 180 children (3–5 years: 40 with speech sound disorders (SSD) and 140 typically developing (TD) peers). Assessments included Percentage of Consonant Correct (PCC), Phonological Mean Length of Utterance (PMLU), Whole-Word Proximity (PWP), and Proportion of Whole-Word Correctness (PWC). Content, construct, convergent, discriminant validity, internal consistency, and test-retest reliability were examined. Exploratory factor analyses supported a robust unidimensional structure across mother (loadings: 0.77–0.95) and father forms (loadings: 0.86–0.98). Known-groups validity demonstrated significant differences between SSD and TD groups, yielding very large effect sizes for mother (Cohen’s d = 2.57) and father ratings (Cohen’s d = 2.39). Convergent validity was supported by strong positive correlations with PCC (r = .71–.72), PMLU (r = .63–.68), PWP (r = .62–.67), and PWC (r = .62–.67, Spearman’s ρ = .617–.667; all p < .001). Significant convergent correlations were found with PCC, PMLU, and whole-word measures. Additionally, the ICS-AZ exhibited excellent internal consistency (α = 0.97–0.98) and test-retest reliability (ICC = 0.98). A cutoff score of ≤3.93 demonstrated favorable diagnostic accuracy, sensitivity: 77.5%, specificity: 97.9%, positive predictive value: 91.2%, and negative predictive value of 93.8%. These findings confirm that the ICS-AZ is a valid, reliable, and clinically precise screening tool for assessing speech intelligibility in Azerbaijani Turkish-speaking preschool children.