Vowel epenthesis in productions of English consonant clusters by Japanese

Phonotactic contraints on syllable structure vary across languages. Japanese has a more restricted set of consonant clusters (e.g., ‘‘honda’’) than English (e.g., ‘‘instruct’’). This presents a problem for Japanese learners of English, who often avoid consonant clusters by inserting epenthetic vowels between consonants. This study examines how often Japanese speakers produce epenthetic vowels in English and the phonetic environments in which they commonly occur. A group of native Japanese speakers, and a control group of native English speakers, read English words embedded in a sentence, and isolated words spoken at normal and slow rates. Measurements were made from spectrograms of the duration of the target clusters, including any epenthetic vowels produced. Preliminary results suggest that Japanese speakers show more instances of epenthetic vowels than do English speakers, and that such vowels are more commonly observed in slow, careful speech than in normal-rate speech. Also, in the absence of vowel epenthesis, Japanese speakers’ productions of consonant clusters differ from those of native speakers in the durational characteristics of component segments. Thus, Japanese speakers’ difficulties in producing English consonant clusters are reflected not just through frequent vowel epenthesis, but also through differences in durational properties in the clusters.