Abstract: Differential thresholds of sound signal duration (△t) and signal interval (△t_i) on 5 subjects were determined at various values of signal duration (t) and interval (t_i) in the range of 5-640 msec. The results were as follow: when t and ti were greater than 40 msec or so, △t/t and △t_i/t_i were nearly constant, being about 7 % on the average; when t and ti were less than 40 msec or so, △t/t and △t_i/t_i increased with the shortening of t and t_i. Making the intensity or frequency components of the standard signal different from that of the variable signal did not seem to have any significant influence on the value of △t/t. On the basis of the obtained data the possible mechanisms of signal duration differentiation and signal interval differentiation, as well as the role of signal duration as a factor in different aspects of auditory analysis was discussed.