Intelligibility in Context Scale: Psychometric evidence and implications for Saudi Arabic-English-speaking...

Purpose: To evaluate the reliability, validity, and diagnostic accuracy (sensitivity, specificity) of the Intelligibility in Context Scale in Saudi Arabic (ICS-SA) and English (ICS-E) as potential measures of functional speech intelligibility in bilingual preschool-aged Saudi Arabian children.Method: The study included 36 parent-child (aged 3;0 to 6;5 years; months) dyads who were bilingual speakers of Saudi Arabic and English, which included two groups-typically developing (TD, n = 29) and suspected speech sound disordered (sSSD, n = 7). The children's intelligibility was evaluated in both languages using the ICS-SA and ICS-E. Children's single-word productions were collected in both languages and calculated for percentage of consonants, vowels, and phonemes correct (i.e. PCC/PVC/PPC) to establish their speech-sound competence.Result: The mean scores for the entire sample (n = 36) were 4.43 (SD = 0.79) for the ICS-SA and 4.48 (SD = 0.79) for the ICS-E, showing that parents rated their children's intelligibility in both languages similarly. Both the ICS-SA and ICS-E demonstrated excellent internal consistency (α = 0.96 and α = 0.95, respectively). There was high inter-rater and test-retest reliability for the ICS-SA, while there was fair to high inter-rater and test-retest reliability in ICS-E. Significant correlations were found for the ICS-SA, but weak correlations were noted for the ICS-E, which indicated fair to moderate evidence of criterion validity. Construct validity efforts indicated a weak correlation with age on both the ICS-SA and ICS-E. The findings also indicated high discriminant accuracy for both the ICS-SA (0.86, 0.86) and ICS-E (0.71, 0.69).Conclusion: This study provides initial validation and reliability evidence for using the ICS-SA and ICS-E with Saudi Arabic- and English-speaking preschoolers, however, ICS-E scores suggest further testing is warranted. By extension, these findings expand the bilingual knowledge base and offer new tools for identifying children in Saudi Arabia who may be at risk for having a speech sound disorder.