Formant Trajectories of English High Tense and Lax Vowels Produced by Korean and American Speakers

Previous studies on the pronunciation of English vowels reported that Korean learners had difficulty producing English tense and lax vowel pairs distinctively. The acoustic comparisons of those studies are mostly based on formant measurements at a single slice of a given vowel section. However, the English vowels usually show dynamic spectral changes across the segment, and only partial data on the vowel segment may be insufficient. The purpose of this paper is to compare the dynamic formant trajectories of English high tense and lax vowel pairs produced by twenty Korean and American males and females. Results showed that the American males and females produced the tense and lax pairs much more distinctly than the Korean counterparts did. Many fine-grained differences along the six measurement points were observed both in the formant trajectories and on the vowel space. These results suggest that more detailed analysis be required in the cross-linguistic comparison of English vowels. Also, the Korean speakers should pay more attention to the dynamic movements of formants in addition to the jaw and tongue positions in order to match those of the American speakers.