Linguagem & Ensino, Pelotas, v.17, n.2, p. 361-90, maio/ago. 2014 361 In search of speech intelligibility: the case of English high front vowels produced by Brazilian learners 1 Alison Roberto Gonçalves Rosane Silveira Universidade Federal de Santa Catarina Abstract: The current study investigates the intelligibility of English high front vowels by focusing on acoustic features of these vowels produced by Brazilian learners. Data were supplied with a sentence reading test containing carrier words with the vowels // and //, which was recorded by 20 Brazilians. An acoustic criterion based on spectral proximity was set to observe whether listeners were sensitive to differences in the first frequency of the vowels produced by the speakers. The listeners were 32 speakers of English from 11 different L1 backgrounds who took an intelligibility test in which they had to orthographically transcribe the missing target-words in the test sentences. Results showed that the tense vowel was the most unintelligible as it was generally mistranscribed by its lax counterpart. In a qualitative analysis, taking into consideration the carrier lexical item, it was found that other phonological processes present in the carrier words, such as consonant devoicing and palatalization, notably hindered intelligibility. Listeners were not sensitive to differences regarding the first frequency, and tended to transcribe the target vowels on the base of durational cues. Keywords: Intelligibility. English vowel. Acoustic cue. L2 phonology. Título: À procura da inteligibilidade da fala: o caso das vogais altas anteriores do inglês produzidas por aprendizes brasileiros Resumo: O presente estudo investigou a inteligibilidade das vogais altas anteriores do inglês focando nas características acústicas dessas vogais produzidas por aprendizes brasileiros. Os falantes foram 20 estudantes brasileiros que gravaram sentenças contendo palavras com as vogais / / e /. Para testar efeitos de proximidade espectral na inteligibilidade, um critério baseado na proximidade espectral do primeiro formante (F1) foi estabelecido. Os ouvintes foram 32 usuários de inglês de 11 línguas-maternas diferentes que fizeram um teste de inteligibilidade em que deveriam transcrever a última palavra nas sentenças do teste. Resultados indicaram que a vogal tensa foi mais ininteligível, pois era inadequadamente transcrita pela vogal frouxa. Em uma análise qualitativa, considerando o item lexical que continha cada vogal, 1 The study protocol was approved of by UFSC Ethics Research Board under the register 242.979 (April 2013). It was funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).