Resolving of successive clicks by the ears and skin.

Abstract

When 2 successive clicks are presented to the [human] ears either a single sound image or 2 successive sound images is perceived, depending on the temporal difference between the 2 stimuli. In agreement with previous findings, the time difference necessary for binaurally resolving 2 equally loud clicks was 1.8 msec. The comparable monaural threshold was 1.6 msec. When the fingertips were stimulated the pulses had to be separated by 10-12.5 msec., depending on the locus of stimulation. In both auditory and cutaneous stimulation manipulation of the intensity relationship between the 1st and delayed stimulus produced large changes in thresholds. As the delayed stimulus was attenuated from 0 to 15 db. the threshold rapidly incrased, but when the 1st stimulus was attenuated from 0-20 db. the threshold decreased slightly at 5-10 db. and then began to increase gradually.