Validation of the Intelligibility in Context Scale as a screening tool for preschoolers in Hong Kong

The Intelligibility in Context Scale (ICS) is a parent report questionnaire for assessing children's speech intelligibility. The original version was developed in English and was based on Environmental Factors identified within the International Classification of Functioning, Disability and Health-Children and Youth Version (ICF-CY). The ICS has been translated into over 30 languages, including Traditional Chinese (ICS-TC). The aims of the current study were to examine the psychometric properties of the ICS-TC with Cantonese-speaking parent--child dyads and to identify speech measures that were more sensitive to the ICS-TC ratings. A total of 72 Cantonese-speaking preschoolers with (n = 39) and without speech sound disorders (SSD; n = 33) were recruited. Native Cantonese-speaking parents completed the ICS-TC independently. The measure showed good internal consistency and test-retest reliability. Correlations with speech performance on the Hong Kong Cantonese Articulation Test (HKCAT), and significant difference in ICS-TC mean scores between the two groups provided preliminary support for the validity of ICS-TC and suggested that ICS-TC can differentiate between children with and without SSD with a large effect size of d = 0.74. The optimal cutoff was estimated using Receiver Operative Characteristic (ROC) curve analysis, giving a sensitivity of 0.70 and specificity of 0.59. ICS-TC mean scores showed a positive correlation with the percentage of initial consonants correct and negative correlation with frequency of atypical errors, and both were moderate in strength. Given the satisfactory psychometric properties of ICS-TC, it may be a valuable clinical tool for screening Cantonese-speaking preschool children's intelligibility.