Babies, for whom words don’t yet exist, vocalise in an increasingly conscious way, using their voices in a ‘singing’ manner, smoothly making random shapes of sounds, which, melodic and vowel-like, are neither music nor language. While their voices are unimpeded, their tongues taste, suck and swallow, and their lips keep busy – free and competent activity, just as it was designed to be. Here we have both the beginnings of sung tone and the ingredients for articulate speech.
Unlike walking, speech needs to be taught.
Harrison, Peter T. The human nature of the singing voice: exploring a holistic basis for sound teaching and learning. Dunedin Academic Pr Ltd, 2006.