Gestural coordination in the production of consonant clusters in children with typical and atypical language development

Author(s)

Aline Mara de Oliveira Vassoler

• Document type: Doctoral Thesis
• Press: São José do Rio Preto. 2016-06-07.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências Letras e Ciências Exatas. São José do Rio Preto
• Defense date: 2016-03-01
• Advisor: Larissa Cristina Berti

Abstract

The syllabic pattern CCV poses a higher level of articulatory complexity when compared to other syllabic types (CV or VC), which contributes to the delayed acquisition of CCV. Some children fail to acquire the CCV pattern at the expected age and reduce CCV to CV. From a Gestural Phonology perspective, the production of CV syllables involves a more stable coordination pattern among articulatory gestures for C and V, whereas the production of CCV syllables involves a more complex and less stable gestural coordination pattern. The simplifications of CCV to CV are associated with different degrees of overlap in the adjacent gestures and/or with the reduction of the magnitude of the gestures. The aim of this paper was investigate and describe, from a Gestural Phonology perspective, the CCV vs. CV syllabic patterns of typical and atypical children. The hypotheses were: H1 – the production of CV and CCV of atypical children would show different ultrasound and acoustic measures (duration); H2 – ultrasound and acoustic measures might differentiate children´s clinical condition; H3 – children with atypical production could show diferences in ultrasound and acoustic measures in the comparison of CCV and CV syllables, although CCV had been auditorily judged as CV. Ten children (five with typical phonological development and five atypical) recorded nine word pairs containing the syllables: CCV and CV. The images and the audio were captured by the software Articulate Assistant Advanced, and subjected to auditory-perceptual analysis, acoustic analysis, and qualitative and quantitative judgement of ultrasound images. Both the auditory-perceptual analysis and the acoustic analysis were performed by three expert judges. The qualitative analysis was carried out through the measures from the contour of the tongue: distance from the tip of the tongue (TT), from the tongue blade (TB) and from the tongue dorsum (TD) up to the inferior limit, and the area encompassing the tip and the blade. Aiming at normalizing the absolute ultrasound measures related to distance, these values were transformed into ratios. The duration and articulatory measures were analyzed by repeated-measures ANOVA. H1 was partially corroborated by ultrasound and acoustic parameters, as long as the measure of the ratios TT/TB, TT/TD and TB/TD and the duration differentiated the syllabic pattern, showing that typical children produce CCV syllable differently from CV. H2 was partially confirmed by the ratios TT/TD and TB/TD and the measure of area between TT and TB. Furthermore, they showed higher values in the production of atypical children. H3 was also partially corroborated by the ratios TT/TD and TB/TD and by the area between TT and TD, which differentiated the CCV and CV syllables produced by atypical children, although the CCV productions had been judged as CV. The articulatory results suggest the presence of a tongue elevation so as to reduce tap with reduced magnitude and the acoustic findings suggest there is not a gestural overlap in the production of CCV. Additionally, in the atypical children group, the results reveal the presence of undifferentiated gestures in the CCV production. (AU)