Signal Detection as a Function of Signal Intensity and Duration

Abstract

The object of this study was to determine how signal amplitude and duration effect the detectability of a pure tone partially masked by random noise. If signal duration and amplitude are considered two dimensions in a space, the study attempted to determine the surface of detectability in this space. To accomplish this task three experiments were conducted with the same observers in each experiment. In the first experiment signal duration was held constant while amplitude was varied. In the second experiment signal energy was held constant while various pairs of values of signal duration and amplitude were tested. Finally, signal amplitude was held constant while signal duration was varied. A three parameter equation was determined which provided a reasonable fit to this surface of detectability in the plane of signal amplitude and duration. The equations are consistent with the data of previous research in this area. Finally, a comparison of the results and the predictions generated by a simple filter model is discussed.