Frequency modulation facilitates (modal) auditory restoration of a gap

In this study we further investigated processes of auditory restoration (AR) in recently described stimulus types: the so-called gap-transfer stimulus, the shared-gap stimulus and the pseudo-continuous stimulus. The stimuli typically consist of two crossing sounds of unequal duration. In the shared-gap and pseudo-continuous stimuli, the two crossing sounds share a gap (<45 ms) at their crossing point. In the gap-transfer stimulus, only the long sound contains a gap (100 ms), whereas the short sound is physically continuous. Earlier research has shown that in these stimuli the long sound is subject to AR, in spite of the gap it contains, whereas the gap is perceived in the short sound. Experiment 1 of the present study showed that AR of the stimuli's long sound was facilitated when its slope increased from 0 to 1 oct/s. Experiment 2 showed that the effect of slope on AR of the long sound also occurred when the slope relationship between the long and short sound was fixed. Implications for a tentative sound edge-binding explanation of AR as well as alternative explanations for the effect of slope on AR are discussed.