Men's voices as dominance signals: vocal fundamental and formant frequencies influence dominance attributions among men

Men's vocal folds and vocal tracts are longer than those of women, resulting in lower fundamental frequency (F0) and closer spacing of formant frequencies (formant dispersion, Df) in men than in women. The evolutionary reasons for these sex differences are uncertain, but some evidence implicates male dominance competition. Previous manipulations of F0 and Df affected perceptions of dominance among men. However, because these acoustic dimensions were manipulated simultaneously, their relative contributions are unclear. In unscripted recordings of men speaking to a competitor, we manipulated F0 and Df independently and by similar perceptual amounts to examine effects on social and physical dominance ratings. Recordings lowered in either F0 or Df were perceived as being produced by more dominant men than were the respective raised recordings. Df had a greater effect than did F0, and both Df and F0 tended to affect physical dominance more than social dominance, although this difference was significant only for Df.