Caratteristiche fonetiche di soggetti a basso rischio neonatologico a 18, 21 e 27 mesi

The phonetic inventories of the spontaneous, meaningful verbal production of three groups of children at 18, 21 and 27 months of chronological age are presented. The first group of children consists of 4 preterm children (< 36 weeks at birth, appropriate weight for gestational age), the second one consists of 4 small-for-gestational age at-term children and the final group comprise 4 appropriate-for-gestational age at-term children. Phonetic inventories were calculated according to the procedures proposed by Stoel-Gammon (1985) and by Ingram (1981). In the paper the two procedures are presented in detail, and compared. Generally speaking, Stoel-Gammon's procedure, counting the presence of a phone in two different words, is much easier to use and then it is recommended for clinical purpose, while Ingram's procedure, taking into account the size of individual vocabulary, is more correct in relating phonetic ability to lexical production. Furthermore, it allows to classify the relative frequencies of the phones. Applying the procedures to verbal productions of the three groups of children, we found that the phonetic inventory of the preterm children are narrower than the other two groups only at 18 months of age, and the differences disappear at 27 months of age.