Individual magnitude estimates for various distributions of signal intensity.

Magnitude estimates of loudness were collected for several variations in the schedule of signal presentations. For wide ranges (about 50 dB centered a t 65 dB), the conditions were: random selection of 21 signals equally spaced in decibels, constrained selection so that each signal was used equally often but successive signals were always close together, constrained selection in which successive signals were always far apart, and random selection from a nonuniform distribution that consisted of two groups of equally spaced signals separated by a gap of 24 dB. In addition, two other ranges, 10 and 30 dB, were run with random selection of 21 equally spaced signals. The measures examined were: mean magnitude estimate as a function of signal intensity, coefficient of variation of the ratio of successive responses as a function of signal separation, and the correlation of the logarithm of successive responses as a function of signal separation. The basic question was whether all of the different schedules of signal presentation produce data that can be viewed as selections from appropriate regions of the 50-dB random signal selection data. To a degree, this was found, but with systematic exceptions.