Abstract:
This research is a study of the perception and production of English monophthongs by Thai speakers with different English-language experience. The hypotheses are: First, Thai speakers with high English experiences will identify English monophthongs more correctly than Thai speakers with low English experiences. Second, Thai speakers with high English experiences will produce short and long vowels more systematically than Thai speakers with low English experiences. Finally, the perception and the production of English monophthongs in Thai speakers with high English experience correlate positively, while in the low group they correlate negatively. The study of vowels perception shows that the experiment group with high English experiences has the percentage of the correct answers at 86%, while the experiment group with low English experiences has the percentage of the correct answers at 80%. Both groups have higher scores in the two-choice perception, when compared to the four-choice perception. The differences in vowels perception are statistically significant at sig. (1-tailed) = 0.0305<0.05 with t-test. The study of vowels production shows that both experiment groups can produce the /i:-I/, /a:-/ and /u:/ monophthong pairs systematically as the native speaker, but the average and the ratio of the duration of the short and long monophthongs are different both at the phonological and the phonetic levels. However, the average and the ratio of the duration of the monophthong pairs of the experiment group with high English experiences are closer to the native speaker than the experiment group with low English experiences. The relationship between the perception and the production is clearly found in the perception and the production of the two monophthong pairs, i.e. /i:-I/and /a:/. However, this relationship does not occur in the /u:/ pairs