CENTRAL AUDITORY GAP DETECTION - A SPATIAL CASE

Normal listeners were tested for their temporal auditory gap detection thresholds using free-field presentation of white-noise stimuli deliv ered from the left (L) and right (R) poles of the interaural axis. The noise bursts serving as the leading and trailing markers for the sile nt period were presented in either the same (LL,RR) or different (LR,R L) auditory locations. The duration of the leading marker was a second independent variable. Gap thresholds for stimuli in which the markers had the same location were low, and usually were independent of the d uration of the leading marker. Gap thresholds for the LR and RL condit ions were longer. These gap thresholds were sensitive to the duration of the leading marker, and increased as the leading marker duration de creased. This finding is consistent with the hypothesis that a relativ e timing operation mediates gap detection when the markers activate di fferent perceptual channels. The present data suggest that this timing process can operate on perceptual channels emerging from central nerv ous system processing. (C) 1998 Acoustical Society of America.