Overcoming non-native overreliance on duration: a study on english vowel manipulation and neutralization

Abstract

The accurate production of an L2 sound is determined by the adequate perception of the target speech sound (Flege, 1993, 1995, 2009). In this respect, Spanish and Catalan speaking learners of English are believed to struggle in their correct identification and subsequent production of the English phonemic vowel contrast /i:/ and /ɪ/, as they assimilate these speech sounds to their single vocalic category /i/ (Best, 1995). Furthermore, the acoustic cues that are used by native speakers when producing those vowels (spectral or quality parameters mainly, together with temporal or duration cues) appear to escape Spanish and Catalan L2 users of the language, who display an overreliance on duration when identifying and producing the targeted phonological distinction. The present study examined both the overwhelming use of temporal cues by 62 non-native listeners of L1 Spanish and Catalan by means of a word identification task, which aurally presented them with words that contained either natural or duration-manipulated /i:/ or /ɪ/ vowels, as well as the possible effects that the neutralization of natural duration values could have on those listeners. This effect was analysed by means of a word discrimination task, which exposed L2 listeners to natural and duration-neutralized tokens in order to make them focus their attention on the spectral values of those vowels. Results of the first test confirmed the tendency evinced by Spanish and Catalan speaking learners of English of overrelying on temporal parameters rather than on quality ones when perceiving the targeted phonemic contrast. The second test, however, yielded inconclusive results, as ceiling effects were obtained, which hindered the comparison of both the discrimination accuracy of duration-natural and duration-neutralized stimuli and the listeners’ performance in the two tasks.