engleski

Development of speech temporal patterns

The early stages of infant speech production were explained by the predominat influence of maturation process. According to that approach since the speech develoment is controlled by factors within the infant there will be no significant influence of the language enviroment on its phonetic structure for a relatively long time. It was supposed that crosslinguistic effects will appear at the stage of the first 50 words. On the other hand some investigation show that the early stages of infant´s speech and language development are under the influence of linguistic enviroment and show linguistic organization. The measurements of the VOT, formant values, coarticulation, assimilation and other acoustic and articulatory parameters show that even when the ambient influence is evident the acurracy and the stability of the articulatory characteristics of the speech production in child speech differs from the adult speakers. In the present study the temporal characteristics of the speech segments of three age groups (10 subjests each) of children (4, 6 and 8 years old) and one group of adults (10 subjects) were compared. Each subject pronunced 5 two word sentences 10 times. Recorded sentences were digitized and the duration of segmental variables (plosives, affricates, fricatives, nasals, aproximants and vowels) were maesured at spectrographic and sound wave forms of the signal. It was supposed that the sounds which appear earlier in the child´s speech inventory will show greater similarity to the adult´s pronunciation and greater stability in their temporal characteristics. The discriminative analyses was used to show the structure of temporal variables differentiating the investigated groups of children and adult speakers. The results show that it is not only the generally faster speech rate of adults but also different sound segments contribute to the difference between particular child age group and the adult speakers.

sound duration; children; VOT

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