Motor Explanations of Babbling and Early Speech Patterns

From the onset of canonical babbling, human vocal output is dominated by the cyclical open-close alternation of the mandible. Mandibular cyclicity has a long evolutionary history in sucking, licking and chewing in mammals, and also appears communicatively in lipsmacks, tonguesmacks and teeth chatters in other primates. It is argued that many of the articulatory regularities in the sound patterns of babbling, and early speech, which closely resembles babbling, (including consonants, vowels, syllables, and many of their detailed attributes) can be attributed directly to properties of this basic mandibular cycle. In addition, some interarticulator synergies evolving with the cycle, plus developmental limitations in changing locus of control between and within articulators during utterances, seem responsible for most other regularities in babbling and early speech.