vocant
A vowel-like sound such as uttered by a preverbal infant.
At an earlier stage still, during the first few months of life, the vowel-like and consonant-like sounds are usually so far removed from normal speech that even this convention is misleading. We will label these sounds vocants and closants and their transcription will be enclosed within double square brackets e.g. bə.
Where it comes from
Coined by British physician John Antony Michael Martin in 1981 (see quotation).
Adapted from the Wiktionary entry vocant (CC BY-SA 4.0).