This paper reports the results of an experimental study on non-native production of English vowels. Two groups of Persian EFL learners varying in language proficiency were tested on their ability to produce the nine plain vowels of American English. Vowel production accuracy was assessed by means of acoustic measurements. Ladefoged and Maddison’s (1996) F1 F2 measurements for American English v...

Recent studies have shown that time-varying changes in formant pattern contribute to the phonetic specification of vowels. This variation could be especially important in children's vowels, because children have higher fundamental frequencies (f0's) than adults, and formant-frequency estimation is generally less reliable when f0 is high. To investigate the contribution of time-varying changes i...

Effects of mora phonemes on Japanese word accent was analyzed statistically, utilizing a set of about 124,000 frequently used common nouns derived from the Japanese Word Dictionary edited by EDR (the Japan Electronic Dictionary Research Institute, Ltd., Japan). In this analysis, Japanese syllable was defined as preceding consonant (+semi-vowel) +following vowel, accompanied / not accompanied by...

One well-known problem with diphone concatenation is the occurrence of audible discontinuities at diphone boundaries, which are most prominent in vowels and semi-vowels. Significant formant jumps at certain boundaries suggest that the problem is of a spectral nature. We have examined this hypothesis by correlating the results of a listening experiment with spectral distances measured across dip...

Seeking classifier models that are not overconfident and that better represent the inherent uncertainty over a set of choices, we extend an objective for semi-supervised learning for neural networks to two models from the ratio semi-definite classifier (RSC) family. We show that the RSC family of classifiers produces smoother transitions between classes on a vowel classification task, and that ...