Experiments have been conducted to determine the dependence of aural recognition of pulsed signals on the pulse length, signal‐to‐noise ratio, and the bandwidth of the filter through which the signal and noise were passed. The pulse lengths used ranged from one‐fourth second to four seconds, and the filter bandwidths ranged from one‐fourth cycle to one thousand cycles and were centered at eight hundred cycles. Signals randomly spaced in the noise background were presented to eight trained subjects. Least‐square estimates of the signal‐to‐noise ratios required for fifty percent signal recognition were made, and their values were plotted as a function of pulse length and filter band width.