Phonetic inventories in Italian children aged 18-27 months: a longitudinal study

The phonetic inventories of 13 Italian children at 18, 21, 24 and 27 months of age are presented. The children were tape-recorded during a play interaction with the mother, and their vocalizations were phonetically transcribed. The individual phonetic inventories were calculated by applying the criteria put forward by Stoel- Gammon [1]: a consonantal singleton or cluster was attested only if word-initially or word-medially present in two different words at least, in a individual vocabulary of 10 to 50 different word types. Variable forms of the same word type were considered only twice. The collective phonetic inventories were calculated for each month on the bases of the number of subjects producing every phone. Further, the consonants at the onset or coda of the syllables constituting the selected words were classified for place and manner of articulations and their frequencies were calculated. Results for the consonantal structures in words and syllables produced by children have been compared to results for consonantal structures of adult words and syllables attempted by the children of 27 months.