The acquisition of an L2 vowel system: A longitudinal investigation of change.

摘要

To what extent do the vowels systems of L2 learners change over time and what types of changes can be expected? The study reported here is a longitudinal investigation of change in the vowel systems of five adult native Spanish speakers learning English. It focuses on eleven vowels of English as uttered in CVC words and in various sentential contexts. Vowel productions from each speaker were measured for the acoustic parameters of F1, F2 and duration. These acoustic parameters were then analyzed via the classification matrices of discriminant analysis and compared over time.;Change in the nonnative speakers was analyzed in two ways: independently of the target and in direct comparison to the target. Research in L2 acquisition has suggested that interlanguage is a system unto itself unlike the native language or the target language (Selinker, 1972). Thus, the nonnative speakers' vowels were first examined independently of the native speakers' vowels. This phase of the analysis showed which vowels were differentiated by a speaker on the three acoustic parameters, which were not, and whether there were changes over time in how vowels were differentiated.;Research in cross-linguistic production has shown that learners may approximate target norms without necessarily achieving them (Flege, 1980). Therefore, in addition to considering the interlanguage of the nonnative speakers, change over time was also examined with respect to the target language. Nonnative speakers' vowels were compared directly to the two native speaker participants in the study. This second phase of the analysis showed whether changes approximated target norms.;Findings indicate that the vowels of nonnative speakers change in ways that reflect dialectal and diachronic changes. Specifically, we see instances of split, merger and shift as described by Labov (1994). It is also the case, however, that changes occur that are unique to L2 acquisition. These changes are undoubtedly related to the learning of orthography and sound-spelling correspondences.;This study provides evidence that intermediate phonological systems arising during L2 acquisition should be viewed not only in terms of the target but as unique systems of contrasts. It also provides evidence that changes are not necessarily unilateral; movement in one aspect of a system can affect other aspects of the system.