Is secondary stress phonetically real for second-language learners? Evidence from Japanese-accented English

Speakers of a non-stress language such as Japanese often have difficulty producing lexical stress distinctions in languages such as English. Distinguishing primary-stressed versus unstressed syllables may be difficult, but distinctions involving secondary stress may be even more challenging. Some studies report that Japanese learners of English (JE) do not distinguish secondary-stressed and unstressed syllables in terms of vowel duration and quality whereas native American English speakers (AE) do. However, the data are limited and inconclusive. To resolve this issue, the present study asked AE and two groups of JE differing in English proficiency to produce 83 English words that exhibit stress shift, e.g., phótogràph-phòtográphic-photógraphy and conducted acoustic analysis of vowels in corresponding positions, which have the same consonantal context but differ in stress level. Preliminary results indicate that JE frequently produce devoiced vowels in unstressed syllables, particularly in phonetic environments similar to where devoicing occurs in Japanese. Devoicing, however, does not seem to occur in secondary-stressed syllables, suggesting that JE might distinguish secondary-stressed and unstressed syllables with respect to devoicing. Results from duration and formant analysis will also be reported and discussed in relation to theories of native-language influences on second-language speech learning. [Work supported by JSPS.]