The Validity, Reliability, and Accuracy of the European French Version of the Intelligibility in Context Scale

The Intelligibility in Context Scale (ICS) is a free parent report questionnaire assessing functional intelligibility. Although it has been translated into French, it lacks validation. This study addresses two main objectives. First, we aimed to establish the psychometric properties of the European French version of the ICS (ICS-EF). Second, we explored the ICS-EF as a measure of the functional impact of speech sound disorders (SSDs), specifically investigating how communication partner familiarity influences intelligibility ratings.

A total of 189 French-speaking preschool children were recruited from preschools: 42 were classified as at risk for SSDs, and 147 were classified as typically developing. Children were assessed using a standardized single-word speech sound test. All parents completed the ICS-EF, and one third completed it a second time for test-retest reliability. Validity was analyzed through Spearman's correlations, and a repeated-measures analysis of covariance (RM-ANCOVA). Reliability was analyzed using Cronbach's alpha and intraclass correlation coefficients. Age groups, cutoffs, and discriminant accuracy were determined using K-means clustering and receiver operating characteristic curves. The effect of familiarity (intelligibility across communication partners) was examined using RM-ANCOVAs.

The ICS-EF demonstrated good validity and reliability and was influenced by age. Three age groups were identified and revealed satisfactory sensitivity for the determined cutoffs. A significant effect of familiarity was found and was modulated by the presence/absence of SSDs.

The ICS-EF demonstrated good psychometric properties and provides ready-to-use cutoffs. The ICS-EF can be considered both as a screening tool for SSDs in French-speaking preschoolers and as a measure of SSDs' functional impacts.

https://doi.org/10.23641/asha.33282180.