English voicing contrast in the production of Persian EFL learners of English

The present paper addresses the acoustic properties of English voicing contrast in the production of Persian EFL learners of English. In a production experiment, we investigated the role of VOT in distinguishing voiced from voiceless stops in English. Examining VOT values of English stop consonants in different phonological positions, we found that like English native speakers, Persian EFL speakers of English pronounce voiceless stops in both word-initial and syllable-initial (intervocalic) positions with long positive VOT values. They were also found to produce voiced stops in word-initial position with short positive VOT and in syllable-initial position with long negative VOT values. However, the results for voiceless stops after /s/ suggested that unlike native speakers of English, Persian learners use long positive VOT values to realize voiceless stops in this position.