On-line version ISSN 1982-0216
MARINO, Viviane Cristina de Castro; BERTI, Larissa Cristina and LIMA-GREGIO, Aveliny Mantovan. Acoustic characteristics of glottal stop associated to Pierre Robin Sequence: case study. Rev. CEFAC [online]. 2013, vol.15, n.2, pp. 466-477. Epub Mar 29, 2012. ISSN 1982-0216. http://dx.doi.org/10.1590/S1516-18462012005000021.
The cleft palate, in association with Pierre Robin Sequence, may foster the development of atypical (compensatory) productions on the child’s speech such as the use of glottal stop as a substitution for occlusive sounds (voiced or voiceless). Acoustic parameters of glottal stop for /k/ and /g/ produced by a 5 year-old girl with cleft palate repaired in association with Pierre Robin Sequence were analyzed. For this study, we used six words consisting of velar stops in the initial word position combining the vowels /a/, /i/ e /u/ in the stressed position were selected. There was total agreement (100%) as for the presence of the glottal stop for both intra and inter-judges. Inspection of the data via spectrogram showed variability of spectral parameters (burst and formant transition), and variations could also be computed, separately considering the vowels. Statistical analysis revealed a statistical difference between the two velar consonants (/k/ and /g/) in spectral (burst), temporal (VOT and duration of occlusion on the word) parameters and those relating to the acoustic features of vowels adjacent to stops (stationary period of F3. The acoustic features of glottal stop suggest that the child may have used strategies to set out phonic contrasts in the language, but these strategies did not have enough magnitude to be perceived by the listener.
Keywords : Speech Acoustics; Spectrography; Speech Disorders; Cleft Palate; Pierre Robin Syndrome.