The prioritization of voice fundamental frequency or formants in listeners' assessments of speaker size, masculinity, and attractiveness.

Key features of the voice--fundamental frequency (F(0)) and formant frequencies (Fn)--can vary extensively among individuals. Some of this variation might cue fitness-related, biosocial dimensions of speakers. Three experiments tested the independent, joint and relative effects of F(0) and Fn on listeners' assessments of the body size, masculinity (or femininity), and attractiveness of male and female speakers. Experiment 1 replicated previous findings concerning the joint and independent effects of F(0) and Fn on these assessments. Experiment 2 established frequency discrimination thresholds (or just-noticeable differences, JND's) for both vocal features to use in subsequent tests of their relative salience. JND's for F(0) and Fn were consistent in the range of 5%-6% for each sex. Experiment 3 put the two voice features in conflict by equally discriminable amounts and found that listeners consistently tracked Fn over F(0) in rating all three dimensions. Several non-exclusive possibilities for this outcome are considered, including that voice Fn provides more reliable cues to one or more dimensions and that listeners' assessments of the different dimensions are partially interdependent. Results highlight the value of first establishing JND's for discrimination of specific features of natural voices in future work examining their effects on voice-based social judgments.