Intelligibility and the Listener: The Role of Lexical Stress

For some 30 years, intelligibility has been recognized as an appropriate goal for pronunciation instruction, yet remarkably little is known about the factors that make a language learner's speech intelligible. Studies have traced correlations between features of nonnative speech and native speakers' intelligibility judgements. They have tended to regard prosody as a global phenomenon and to view intelligibility as primarily a quality of the speaker. The present article focuses on a single prosodic element, lexical stress, and shifts the focus of study to the listener. It draws on findings in psycholinguistics that have rarely been applied to second language (L2) contexts. Groups of listeners were asked to transcribe recorded material in which the variables of lexical stress and vowel quality were manipulated. Recognizing the extent to which English is employed in international contexts, the study contrasted the effect of the variables on native listeners (NLs) with their effect on nonnative listeners (NNLs). NLs and NNLs were found to respond in remarkably similar ways to the problems posed by stress misallocation. For both groups, the extent to which intelligibility was compromised depended greatly on the direction in which stress was shifted and whether changes in vowel quality were involved.