1 Vocalisations and babbling

From birth, infants make a variety of sounds including vowels (e.g. ‘ooo’), squeals and high-pitched yelps (e.g. ‘eee’), primitive consonants (e.g. ‘mmm’) and other vocalisations. Around 6 months of age these sounds change into something more language-like, and they start to resemble the speech they hear around them. For instance, French-learning babies babble in syllables that most closely match adult French than English-learning babies (Morgan and Wren, 2018). This shows that infants are fine-tuning their sound production, even before they know what any of the words mean yet.

The typical form that this babble takes is a consonant-vowel or vowel-consonant combination with a smooth, neatly timed transition between the two elements (e.g. ‘ba’ or ‘da’). Infants soon learn to reduplicate these elements (e.g. ‘baba’, ‘dada’) then recombine them into new combinations (e.g. ‘bada’, ‘daba’). This is a gradual change that often makes it difficult to conclusively decide where syllabic babbling ends (e.g. ‘ma ma’) and their true first words begin (e.g. ‘mama’).

So far in development, infants’ language capabilities have largely been about what they understand about their comprehension. Babbling represents a major developmental milestone: their first linguistic production and a foothold into becoming competent partners in the conversation.