Emergência dos gestos articulatórios na aquisição do tap em sílaba CVC: aspectos acústicos

Abstract

The present work seeks to investigate the process of acquisition of tap in CVC syllable, in medial and final position of word, based on Articulatory Phonology The [ɾ] is one of the last segments to emerge in the child speech, presenting several changes during their acquisition period. Generative-based studies analyzed the acquisition of syllabic structures and phonemes in Brazilian Portuguese. Despite the contributions brought by those studies, the phonetic detail, which is not perceived auditorily, was not considered as a clue for the markedness of potential phonological contrast. More recent works, emergentist-based, such as Rodrigues (2007), consider articulatory gesture as primitive analysis. Thus, it is possible to represent phonetic detail at the grammatical level. In this sense, the present study investigates the presence of covert contrasts on tap productions in the phonetic-phonological acquisition of Brazilian Portuguese. Oral data productions of one control subject, four cross-sectional subjects and a longitudinal subject were analyzed. The data collections were recorded with a Zoom H4n digital recorder in an acoustic booth at the Emergency of Oral Language Laboratory (UFPel). The rhotic was in stressed syllable, in the context of [a], [i] and [u], in medial and final position of the word. A corpus of word triads was elaborated, with the presence of the rhotic, its omission and the presence of the palatal diphthong, presented by means of an instrument for naming images. Acoustic analysis revealed 28 possible contrasts for 129 tap production possibilities in the speech of cross-sectional informants. In the longitudinal informant's speech, the presence of 51 possible covert contrasts in 142 possibilities of occurrence of the segment was identified. The rhotic variant most used in children speech was the tap, but productions of trill, retroflex approximant, alveolar approximant, glottal fricative and fricatized tap were also identified. When not being able to produce the tap, it was possible to infer that the children used strategies of gestural reduction, gesture substitution, while intrusive gestures may also have occurred. Visual inspection of spectrograms and analysis of the formant trajectory were fundamental to evidence possible covert contrasts in progress on children's speech. When observing the behavior of vocalic elements from the comparison between them and the final portion of a nuclear vowel, it was found that only vocalic elements produced in the context of [u] tend to centralize. Thus, the results indicate a relation between the vocalic element and the nuclear vowel in the CVC syllable. Thus, it is expected that this work has contributed to evidence that gradient productions, expected by Articulatory Phonology, are detected in the emergence process of rhotic segments. The analysis of the data, from the perspective of a theoretical model that considers the dynamic character of the language, enables the interpretation of gradient productions as clues to the emergence of the acquisition of the language contrast system.