Humans are able to produce a wide variety of sounds in part because they have descended voice boxes that makes room for longer vocal tracts. Evolutionarily, this appears to have occurred before, and thus may have facilitated the evolution of language. But why would our larynxes descend in the first place? One theory is that longer vocal tracts enabled us to make lower noises in order to sound larger and more threatening. Red Deer, for example, use a descended vocal tract for this purpose. The theory is supported by the fact that in males the voice box descends further during puberty (when... more
