Age- and Gender-Specific Normative Information from Children Assessed with a Dichotic Words Test
1Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA.
Background:
The most widely used assessment in the clinical auditory processing disorder (APD) battery is the dichotic listening test. New tests with normative information are helpful for assessment and cross-check of results for reliable diagnosis.
Purpose:
The Dichotic Words Test was developed for use in the clinical test battery for diagnosis of APD. The test stimuli were common single syllable words matched for average root-mean-square amplitude and each pair was temporally aligned at both onset and offset. The study was conducted to collect performance results from typically developing children to create normative information for the test.
Research Design:
The study follows a cross-sectional design.
Study Sample:
Typically developing children (n = 416) between the ages of 5 and 12 yr were recruited from schools in the community. There were 217 males and 199 females in the study sample. Only children who passed a hearing screening were eligible to participate.
Data Collection And Analysis:
Scores for each ear were recorded during administration of the first free recall version of the test. Ear advantages based on results recorded for left and right ears were used to measure prevalence of right, left, and no ear advantages. Results for each listener's dominant and non-dominant ears and the absolute difference between them were put into the data analysis. Results were analyzed for normality and because no results were normally distributed, all further analyses were done with nonparametric statistical tests. Normative data for dominant and non-dominant ear scores and ear advantages were determined at the 95% confidence interval through bootstrapping methods with 1,000 samples.
Results:
Children were divided into four age groups based on results in their dominant ears. Females generally performed better than males and the prevalence of a right-ear advantage was ∼60% across all children tested. Normative lower-bound cut-off scores were established for males and females within each age group for dominant and non-dominant ear scores. Normative upper-bound cut-off scores were established for males and females within each age group for ear advantage scores.
Conclusions:
Normative information specific to age group and gender will be useful in clinical assessment for APD. Prevalence of left-ear advantage results in the sample may have been partly due to uncontrolled influences of voice-onset time in arranging the dichotic pairs.
