Abstract Abstract Abstract Abstract Abstract This article is an attempt to answer the following question: Is vowel insertion in the speech of Brazilian learners of English likely to be a source of unintelligibility? Insights to answer this question are provided on the basis of an analysis of empirical data derived from three studies which investigated the pronunciation intelligibility of Brazilian learners' English to three different groups of listeners. Samples containing words with vowel insertion, produced by Brazilian learners of English, were presented to three different groups of listeners who have the following three characteristics: (1) British listeners living in Birmingham, England, unfamiliar with the way Brazilians pronounce English words (1 st study); (2) British and American listeners living in Brazil, familiar with the way Brazilians pronounce English words (2 nd study); and (3) a second group of American and British listeners, also familiar with the Brazilian way of pronouncing English words (3 rd study). The listeners were asked to listen to the samples once, and to carry out tasks. In one of the tasks, they were required to write down what they had heard. The analysis focused on the 134 Neide Cesar Cruz listeners' orthographic transcriptions of the samples. On the basis of the results obtained, I argue that the category vowel insertion in itself is insufficient and too broad to provide an answer to such a question. Instead, I suggest that it is necessary to specify the type of vowel inserted, as well as the strength with which it is produced, when vowel insertion is considered in Brazilian learners' pronunciation intelligibility
