The human voice might have been shaped by sexual selection. Hence, voice fundamental (F0, or pitch) and formant frequencies (Fn, or timbre) are proposed to convey fitness cues germane to rivals and potential mates. First, I confirm the independent effects of F0 and Fn on listeners’ assessments of speaker size, masculinity, and attractiveness. Second, I quantify the just-noticeable differences in both vocal features and then place F0 and Fn cues in conflict by equally discriminable amounts to test their relative influence on such voice-based social judgments. Results revealed a greater relative role of Fn in listeners’ ratings of all three dimensions, suggesting that these dimensions might all be cued more reliably by Fn than F0. Alternatively, given post-hoc principal component analyses that revealed considerable overlap in ratings of size, masculinity, and attractiveness, listeners’ conceptions of these dimensions may not be independent despite a research tradition that assumes they are. / xi, 102 leaves : ill. ; 29 cm