Comparison of plosive sounds in monolingual and bilingual children, using the voice onset time acoustic parameter: cases report

ABSTRACT The purpose was to compare differences in production of plosive phonemes through the voice onset time (VOT) measurement in the speech of monolingual children, speakers of Brazilian Portuguese and bilingual children, speakers of both Brazilian Portuguese and English. The sample consisted of three monolingual children and three bilingual children; average age was 7 years. A speech emission was recorded for the investigation, which had the following vehicle phrase: “Diga ‘papa’ baixinho” (“Say ‘papa’ quietly”). Papa was then replaced by “baba”, “tata”, “dada”, “caca” and “gaga”. The measurements of the acoustic signals were performed through broadband spectrograms, and VOT was descriptively analyzed for the non-voiced sounds [p, t, k] and voiced [b, d, g] plosive sounds. Monolingual children presented higher average VOT values for [p, t, k] compared to bilingual children. For the [b, d, g] sounds, monolingual children had lower average VOT values, as compared to bilingual children. It was concluded that in the comparison of VOT measures of the speech samples, the monolingual children of Brazilian Portuguese presented higher values for the non voiced ones and lower for the voiced ones in relation to the bilingual children speakers of Brazilian Portuguese and English.