Intelligibility of English L2: The effects of lack of vowel reduction and incorrect word stress placement in the speech of French and Italian learners

There is a debate in the literature on whether the intelligibility of English second language (L2) speech is more affected, among other things, by incorrect vowel reduction or by incorrect word stress placement. Identifying which features interfere most with intelligibility will assist in selecting what to prioritize in teaching pronunciation. The focus of this pilot study was to determine how incorrect vowel reduction or incorrect word stress placement, alone or in combination, impacts the intelligibility of Canadian French (CF) and Italian (I) L2 English. A close shadowing test was administered in which native (L1) English speaker/listeners responded to CF‐ and I‐accented English words containing naturally occurring word stress and vowel reduction errors in various combinations. Correct word identification and reaction time results confirm that both incorrect stress and vowel reduction interfere with L2 intelligibility. Results also suggest that even though misplaced word stress is damaging to intelligibility, incorrect vowel reduction is more detrimental.