Four expts. were run involving judgments of the loudness of tones presented one at a time. Three of the expts. spaced the presented stimuli 5 db apart, and one of these used a range of 5 to 100 db, another 55 to 100 db, and the third 5 to 55 db SPL. The 4th expt. used the 5 to 100 db range, but spaced stimuli according to loudness rather than log intensity. From these expts. scales of equal discriminability were constructed. The conclusions from these expts. are: 1. The scale of equal discriminability constructed from loudness judgments bears the same relation to intensity as a scale of cumulative DL''s for intensity. Thus the discriminative process is the same for absolute and comparative judgments. 2. Any exptl. series of tones has definite limiting intensities at the high and low ends. Relatively better discrimination is shown near these limiting intensities, and it is suggested that a subjective anchor occurs at these points. 3. Spacing the presented stimuli non-uniformly on the intensity continuum does not change the scale of equal discriminability as long as the limiting intensities are the same. 4. The amt. of information which stimuli can transmit about some other series of events will be greatest when the stimuli are spaced according to a criterion of equal discriminability.