PURPOSE: to submit a study on the auditory perception that adults have on the characteristics of voiced and unvoiced stops produced by 3-year-old children. METHODS: first, the characteristics found in the production of stops were acoustically inspected in relation to (1) obstruction interval, (2) burst, and (3) quantitative analysis of Voice Onset Time (VOT), measured in six plosives found in Brazilian Portuguese (BP). The carrier sentence "Diga ______baixinho", produced by four 3-year-old children - three male and one female, Brazilian Portuguese native speakers - was submitted to wide-band spectrographic analysis using PRAAT software . Second, the corpus produced by the children was submitted to 120 adult individuals in an identification type perception test. RESULTS: the production showed uncommon characteristics for adult speech in relation to both voiced and unvoiced stops. The test showed that the adults perceived the unvoiced stops as voiced due to the presence of breathy vowel. The voiced plosives were always correctly identified. The articulatory position of the bilabial, alveolar and velar stops did not interfere in the way the stops were judged. The ANOVA test (sig = 0,05) showed that the plosives were correctly identified when they presented breathy vowel or voicing with over 60% of voicing. The presence of aspiration did not interfere in the unvoiced stops judgment. CONCLUSION: the results indicate the relevance of acoustic phonetics analysis in studies on the production and the perception of speech, which may help to elaborate therapeutical procedures and facilitate the follow-up of their development.
Child; Speech; Sound Spectrography; Speech Perception
