Construindo categorias sonoras: o vozeamento de consoantes obstruintes em surdos profundos usuários de língua de sinais (LIBRAS)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This dissertation aims to analyse the voice properties of obstruent consonants in Brazilian Portuguese, specifically the stops [p, b, t, d, k, g], the fricatives [f, v, s, z, ., .] and the affricates [t., d.], in pre-lingual deaf users of Brazilian Sign Language (Libras). The aim of the project was to investigate the contribution of dactylology (Libras manual alphabet) in the construction of sound categories by the deaf. Six deaf subjects and a control group of six subjects with hearing participated in five experiments. The experiments were composed of tasks designed to nominate words and logatomes in communicative speech and lip reading, dactylology and printed illustrations. The obstruent consonants investigated were located at the initial position of the word. The deaf participants were between the ages nine to 14 and those with hearing, between 18 and 30. All responses were recorded and filmed and the Praat software program provided the acoustic analysis. The following acoustic measures were investigated: the VOT (Voice Onset Time) of stops, duration of fricatives, VOT and duration of affricates, the presence/absence of bar voicing and the duration of the vowel following the obstruent. The results showed that the phonetic inventory of the deaf is reduced when compared to those with hearing, being that all the deaf participants manifested only voiceless obstruents. The VOT values for stops were always positive, showing the presence of solely unvoiced sounds. The absence of the bar voicing in the spectrogram confirmed that all obstruents investigated were unvoiced. VOT measures for stops, duration of fricative, VOT and duration of affricates presented an unsystematic characterization regarding the properties of voicing for obstruent consonants amongst deaf participants. It was not possible to find fine phonetic detail generalizations which expressed the voice contrast in obstruents since all deaf participants presented only voiceless sounds. Complementary research showed that the lengthening of the vowel which follows the obstruent occurred as a strategy to express the voice contrast which was utilised by the deaf participants, principally by those who were more proficient in sign language. It was furthermore observed that deaf participants who had a higher degree of proficiency in Libras had a greater tendency to lengthen the vowels. The fine phonetic detail in the construction of sound categories was investigated by measuring the duration of the vowel following the obstruent, according to the postulates of cognitive theories of mental representation in the Usage-Based Phonology and Exemplar Models. The results indicate that the deaf use fine phonetic properties in the construction of specific sound categories. The results also show that the categorization of voiced and voiceless sounds is most effective when the deaf subject is exposed to various stimuli such as video, audio and Libras. The use of dactylology alone did not influence the construction of sound categories by deaf participants in the tests. We suggest that these results express a holistic view of the construction of linguistic categories by the deaf. Future work will investigate the fine phonological properties of other consonants, and also the role of Libras proficiency in the acquisition and use of specific phonological categories.

ASSUNTO(S)

lingüística teses. lingua portuguesa consoantes teses. surdez teses. língua portuguesa fonologia teses. fonética teses. surdos linguagem teses. fonética acústica teses. linguagem brasileira por sinais teses. sons da fala teses.

ACESSO AO ARTIGO

Documentos Relacionados