Validation of the LittlEARS Auditory Questionnaire in cochlear implanted infants and toddlers

The LittlEARS Auditory Questionnaire (LEAQ) has so far been validated to assess auditory development in groups of normal-hearing children in over 20 different languages. Considering the huge variability in auditory development of CI children, especially since candidacy criteria have been relaxed, additional evidence to validate the use of LEAQ scores in this particular population is needed. The aim of this study is to provide evidence for the reliability and validity of LEAQ scores for assessing the auditory development of CI infants and toddlers based on an evaluation of LEAQ's internal structure and its relation to other variables.

The study was prospective, with sequential enrolment and within-subject repeated measures. It included 122 children with profound bilateral sensorineural hearing loss implanted at 6-22 months of age. All children were evaluated with the Polish version of LEAQ on the first day of CI activation and at each of four follow-up visits related to sound processor fitting. The study was undertaken in the light of current psychometric thinking about how assessment instruments should be validated. The main aim of the study was to obtain evidence for the validity of interpreting LEAQ measures from CI children in terms of auditory development. First, in order to collect evidence for score reliability and validity based on LEAQ's internal structure, the psychometric properties of LEAQ scores from CI children were determined. A second step was to confirm validity by investigating the effect of concomitant variables on LEAQ scores. Correlations between LEAQ score and duration of hearing aid (HA) use, and between LEAQ score and duration of CI use, were investigated. Additionally, group differences in LEAQ scores between: 1) early and late implanted children; 2) children with long and short HA experience prior to implantation; and 3) children who showed responses over a wide frequency range from using their HAs (prior to implantation) vs those who did not.

On each of the five administrations of LEAQ, the item difficulty indices increased (meaning the items became easier) and over the series they progressively increased with a range of: 0.01-0.62, 0.03-0.92, 0.09-1.00, 0.26-1.00, and 0.52-1.00. At the same time, item-total correlations were in the ranges: 0.09-0.77, 0.26-0.62, 0.00-0.65, 0.00-0.65, and 0.00-0.67. Cronbach's alpha values were above 0.80 for all administrations. A positive correlation between LEAQ score and duration of HA use, and subsequent duration of CI use (hearing experience) was found. When the children were stratified into groups according to age at cochlear implantation, duration of HA use before implantation, and audibility provided by HAs prior to implantation, the differences between the groups were reflected in both their rate of auditory development and their LEAQ score.

The interpretation of LEAQ scores from CI children in terms of auditory development was supported by the validity evidence of internal structure and from a logical relationship to other variables. (1) Psychometric properties - item difficulty, item-total correlations, and Cronbach's alpha values - indicate that LEAQ measures are highly consistent and reliably gauge the level of a CI child's auditory development. (2) There was a positive correlation between LEAQ scores and the duration of hearing experience with HAs and a later CI; similarly, there were significant differences between groups of children stratified according to the age at cochlear implantation, duration of HA use before implantation, and audibility provided by HAs prior to implantation, all of which demonstrate the expected relation between LEAQ score and concomitant variables.