Title

Gestural organization in the speech of twenty-two to thirty-two-month-old children

Date of Completion

January 1991

Keywords

Language, Linguistics|Speech Communication|Psychology, Developmental|Psychology, Experimental

Degree

Ph.D.

Abstract

Standard approaches to child phonology have typically assumed that young children first master a repertoire of phonemes and then build their lexicon by forming combinations of these abstract, contrastive units. However, evidence from children's systematic errors as recorded in phonetic transcriptions suggests that children first build a repertoire of words and phrases as integral sequences and then gradually differentiate these sequences into their segmental components. If the latter position is correct, we might expect that children learning to talk would plan the articulation of a word as an integral pattern of overlapping gestures rather than as a sequence of discrete segments. Evidence for a larger planning unit might then be found in more extensive gestural overlap within and across syllables in young children than in adults. Recently, evidence supporting this position has been found in the acoustic records of the speech of 3-, 5- and 7-year-old children suggesting that even in older children some phonemes have not yet fully segregated as units of gestural organization and control. The present study extends this work to younger children, the majority of whose utterances at the beginning of the study were still single words.^ Twelve subjects (six girls, recorded over a ten-month interval at mean age 22 months and 32 months, and six adult females) produced the nonsense disyllables: (be'ba), (be'bi), (be'da), (be'di), (be'ga), (be'gi), ('sisi), ('sasa) and ('susu). Discrete Fourier Transform spectra of each speech token were computed in order to measure four types of gestural overlap: (a) cross-syllabic vowel-to-vowel, (b) cross-syllabic stop consonant-vowel, (c) intra-syllabic vowel-to-stop consonant, and (d) intra-syllabic vowel-to-fricative. Results indicate that for comparisons (a-c) younger children display significantly greater effects of gestural overlap in a variety of contexts than do their older selves and adults, as demonstrated by ratios of formant estimates indicating lingual position (front-back and height). In the case of (d) the children at both ages displayed significantly greater gestural overlap than did adults. The overall results of the present study are consistent with previous research suggesting that the domain over which children organize articulatory gestures narrows during childhood. ^