Intelligibility in Context Scale: Sensitivity and specificity in the Jamaican context

The present study investigated the sensitivity and specificity of the English Intelligibility in Context Scale (ICS) and the ICS-Jamaican Creole (ICS-JC) translation with bilingual preschool-aged Jamaican children. Participants in this study were 262 English-Jamaican Creole simultaneous bilingual children (aged 3;3 to 6;3, M = 4;11, SD = 7.8). The ICS and ICS-JC were administered to parents in auditory form, rather than written form. Although recent evidence has demonstrated the validity and reliability of the ICS as an assessment tool in various languages, further data are needed to determine diagnostic accuracy of the ICS and ICS-JC in Jamaican children. The sensitivity and specificity of both tools were high in this cohort of children, indicating that in the Jamaican context, these versions of the ICS could be used as screening tools to identify children who require further assessment of speech sound disorders. A cut-off score of 4.12 was used for both tools to achieve high sensitivity (0.84) and specificity (0.70) values for the ICS, as well as high sensitivity (0.84) and specificity (0.71) for the ICS-JC. The results of this study also demonstrate that administration of the auditory ICS is a valid way of collecting parent reports about children's speech intelligibility, which has implications for use of the ICS in languages with no written form or with parents who have a low level of literacy in the languages they use. This investigation is relevant not only to this underserved population but broadens knowledge of research-based tools for working with bilingual children.