Across- and Within-Channel Gap Detection Thresholds Yielded by Two Different Test Applications.

Background: Individuals with auditory processing disorders show some deficits with the temporal processing of auditory signals. Gap detection measurements are commonly used to assess temporal processing skills across different listening tasks.

Purpose: The aim of this study was to compare the gap detection thresholds (GDTs) in across-channel (AC) and within-channel (WC) tasks by using two computer applications-Adaptive Tests of Temporal Resolution (ATTR) and Psycon.

Research Design: A within-subject study design.

Study Sample: Twenty-one young adults with normal hearing participated in the study.

Data Collection And Analysis: Each participant's gap detection performance was assessed using the narrowband noise stimuli of the ATTR and Psycon applications. Four conditions were administered with 2 kHz as the leading frequency marker before the gap and 1 kHz as the trailing frequency marker after the gap for AC tasks, and with 2 kHz as both the leading and trailing frequency markers for WC tasks.

Results: The results showed lower GDTs for the WC tasks than the AC tasks. Also, the GDT values for the WC tasks were lower in the ATTR than Psycon; whereas the GDT values for the AC tasks were higher in the ATTR than Psycon.

Conclusion: The differences noted in the obtained GDT values from the ATTR and Psycon applications may be attributed to subtle spectral differences in the stimuli of the two programs. The present study also indicates that because of the inherent differences in the stimuli generated by the different software, the normative values for GDTs may need to be established according to evaluation tools before drawing conclusions about clinical conditions.