Measured changes in finger volume (FV) and finger pulse volume (PV) in 19 19-21 yr old male Swedish military conscripts using 2 pneumoplethysmographic methods. 11 identical randomly spaced auditory stimuli were given. 5 habituation estimates were calculated: H-score, parametric beta, parametric correlation, Kendall's tau, and nonparametric beta. Both FV and PV responses habituated, PV responses faster than FV. The correlations between FV and PV responses were significant and moderately high. Some surprisingly low correlations were obtained among the different habituation estimates, indicating that the choice of habituation estimate is of great importance, and might influence the result profoundly. Differences in response latency found between FV and PV responses are discussed in terms of measurement technique. (20 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)