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, D_f) 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 D_f 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 D_f independently and by similar perceptual amounts to examine effects on social and physical dominance ratings. Recordings lowered in either F₀ or D_f were perceived as being produced by more dominant men than were the respective raised recordings. D_f had a greater effect than did F₀, and both D_f and F₀ tended to affect physical dominance more than social dominance, although this difference was significant only for D_f.