An Item Response Theory-Based Validation of the Vanderbilt Classroom Listening Assessment Short Survey for Children With Unilateral Hearing Loss

OBJECTIVES: The Vanderbilt Classroom Listening Assessment Short Survey (VCLASS) was previously developed as a tool to monitor listening difficulties experienced by school-aged children in classrooms. However, the previous statistical approach used in the initial validation did not fully evaluate the questionnaire's psychometric properties, did not take into account the ordinal nature of responses, and did not contrast hearing-aided versus hearing-unaided conditions. The present study aimed to evaluate the psychometric properties of the 15‑item VCLASS using item response theory (IRT) in both hearing-aided and unaided conditions. More specifically, we aimed to (1) assess the latent structure for each listening condition (unaided and aided); (2) determine appropriate IRT-based models to estimate item discrimination and threshold parameters for each listening condition; (3) assess reliability from the IRT-based model; and (4) evaluate both uniform and nonuniform age-related differential item functioning (DIF) under each listening condition. DESIGN: We applied IRT-based analyses to analyze responses previously collected from children aged 9 to 17 years with unilateral hearing loss. All children (n = 1148) completed the VCLASS imagining they were not using a device (unaided); most children (n = 897) also completed the VCLASS imagining they were using their personal listening device (aided). For each listening condition (unaided, aided), dimensionality of VCLASS items was assessed taking into account the ordinal nature of responses. Next, the best-fitting models were used to estimate item discrimination (â) and threshold parameters (β̂1 to β̂4), to evaluate item and person fit, and to examine reliability. Last, age-related uniform and nonuniform DIF were assessed for each listening condition. RESULTS: Parallel analysis based on polychoric correlations supported a two-factor structure for both the hearing-unaided and hearing-aided conditions. In both conditions, response patterns were largely captured by a dominant, general school-related listening-difficulty factor; additionally, one item (when unaided) or four (when aided) items loaded on a specific/minor factor representing school-related close-proximity listening difficulty. The two-factor graded response model provided better model fit relative to the two-factor generalized partial credit model. All items showed good fit and high discrimination. IRT-based marginal reliability for factor score estimates was strong (unaided: 0.88 and 0.89; aided: 0.86 and 0.85 for factors 1 and 2, respectively). Test information curves indicated greatest measurement precision where there were the most sample respondents-which included low, middle, and high, but not extreme, levels of listening difficulty-with comparable profiles across listening conditions. Age-related DIF effects on item responses were negligible, supporting age-invariant measurement. CONCLUSIONS: The IRT-based validation confirms that the VCLASS provides a reliable and consistent measure of classroom listening difficulty across unaided and aided listening conditions in children with unilateral hearing loss. By considering the ordinal nature of the data in both modeling and missing data imputation, current results support a two-factor structure across unaided and aided conditions. We also demonstrated that the VCLASS has strong item functioning and trivial age‑related bias. The VCLASS provides listening difficulty scores on an interval‑level continuum for classroom listening difficulties, supporting its use in clinical and research settings for children with unilateral hearing loss.