Fifty-four voices from two: the effects of simultaneous manipulations of rate, mean fundamental frequency, and variance of fundamental frequency on ratings of personality from speech.

Utterances of two adults males were analyzed and synthesized by a fast Fourier Transforms method. Each of the two voices was synthesized in each of the twenty-seven combinations of three levels each of rate, mean FO, and variance of FO (a total of fifty-four "voices" generated from two). The effects of the rate, mean FO, and variance of FO manipulations, the interactive effects of rate and variance of FO, and the effects due to speaker were all statistically significant predictors of personality ratings given the voices. They accounted for 86%, 4%, 3%, 2%, and 1% of the variance, respectively, in competence ratings and 48%, 1%, 6%, 1%, and 8% of the variance, respectively, in benevolence ratings. Increased speaking rate was found to decrease the benevolence ratings, and decreased rate was found to decrease competence ratings. Decreased variance of FO was found to decrease the ratings on both competence and benevolence. Increased mean FO in these mhle voices was also found to decrease competence and benevolence ratings.