Effect of vocal disguise on estimations of speakers' heights and weights

The purpose of this investigation was to determine the effect of speakers' attempts to disguise their voices on listeners' accuracy in judgments of height and weight. A total of six sentences were recorded by 26 speakers, 13 females and 13 males, under five conditions: in a normal manner (control condition) and in a manner in which they attempted to sound much taller and much shorter, as well as much heavier and much lighter than they actually were. Five master tapes were constructed, a control tape and four disguise tapes. Each tape contained a total of 156 sentences arranged in random order. A total of 40 judges, 20 in the height-estimation experiment and 20 in the weight-estimation experiment, participated in three sessions, one for each of the three master tapes (one control and two disguise tapes) in each experiment. They were asked to judge the height and weight of the speaker of each sentence and, using a seven-point confidence rating scale, to indicate the over-all confidence in their judgments at the end of each session. Although a majority of speakers yielded height and weight estimates consistent with the intended disguise conditions, the differences in listeners' estimates among all conditions were relatively small. Moreover, differences between speakers' actual heights and weights and listeners' height and weight estimates in the normal (control) condition were also relatively small. Implications of these findings and suggestions for future research are discussed.