Auditory Temporal Gap Detection in Children with and without Auditory Processing Disorder

Background: Auditory gap detection is a measure of temporal acuity. The paradigm comes in two forms, distinguished by whether the sounds bounding the silent period are the same (within channel [WC]) or different (between channel [BC]). Purpose: The purpose of this study was to test normal children and children referred for auditory processing disorder (APD) assessment, with both gap detection paradigms. Research Design: Best gap durations (i.e., shortest reliably detected gaps) were measured in a two-interval, two-alternative forced-choice design embedded within a modified method of limits, for both WC and BC paradigms, with stimuli presented at 55 dB HL. Study Sample: Sixteen control children and 20 children referred for APD assessment participated in the study. Of the 20 referred children, 9 were diagnostically positive for APD (APD+), and 11 were negative (APD-). The mean age of children in all three groups was 10-11 yr. Data Collection and Analysis: Data collected were best gap durations for each paradigm, for each child. Group differences were assessed using Kruskal-Wallis analyses of variance. Results: WC best gap durations were very similar across the three participant groups. BC best gap durations varied significantly between listener groups, with the greatest difference being between controls and APD+ samples. Conclusions: BC best gap durations differed among the listener groups while WC ones did not. This suggests that the relative timing perceptual operations required by the BC task are more susceptible to the perceptual disturbances in APD than is the simple event detection required by the WC task.