Comparative study of intensity in the speech of native speakers and Japanese speakers of English

This paper presents a comparative analysis of the intensity of words in sentences uttered by Japanese speakers of English and native speakers of English (Japanese English and native English, henceforth). We investigate two parameters: intensity, which is defined here as the integral of the power for each word, and power peak, which is defined as the peak of the power for each word. The analyses reveal differences in both word class and word position. For word class, the nouns, interrogatives and negatives for Japanese English are produced with less intensity, whereas most function words are produced with more intensity than are their native English counterparts. For word position, Japanese English sentence-final words are produced with less intensity than are their native English counterparts. Also, Japanese English sentence-initial words show lower power peak, and the sentence-final words show higher power peak than are their native English counterparts. Detailed analyses reveal a correlation between the above results and subjects' English proficiency. The results for word class can be explained as a result of the Japanese speakers inserting Japanese focus into English utterances. The results for word position are explained such that while sentence-initial strengthening does not affect sentence-initial power peak in Japanese English, an irregularity of final lengthening affects sentence-final intensity.