• Speech Sciences
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• v.5 no.2
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• pp.131-138
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• 1999

This study was done to investigate the English front vowels /e/ and /${\ae}$/. These vowels are difficult for Koreans to discern and pronounce. So they show a foreign accent in pronouncing them. In order to find out the reason for Koreans' foreign accent, experiments are carried out with the help of acoustic instruments. The results of the experiment show that there is a considerable difference, especially in vowel length, between the way Korean and Americans pronounce the two English vowels, /e/ and /${\ae}$/. When Americans pronounced English front vowel /e/ and /${\ae}$/ there was a big difference in vowel length between the two vowels. But for Koreans there was only a little difference between two vowels and as a result Koreans showed a foreign accent when they spoke these two English front vowels. Therefore we need to consider the difference of vowel lengths between /e/ and /${\ae}$/ in teaching English pronunciation.

• Phonetics and Speech Sciences
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• v.2 no.1
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• pp.51-58
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• 2010

This study investigates the perception and production of English front vowels focusing on the distinction in /i/ vs /I/ and /$\varepsilon$/ vs /$\ae$/ by sixty-one Korean speakers. The first portion of this study focused on the perceptional discrimination by the subjects of two sets of English vowel contrasts, /i/ vs /I/ and /$\varepsilon$/ vs /$\ae$/. In the second portion of the study, the production of these vowels by the same subjects who had participated in the perceptional discrimination test was examined acoustically and subsequently compared with that of the control group comprised of native English speakers. The major results indicate that: (1) In perception tests, Korean subjects can discriminate between /i/ and /I/ relatively well, while many of them were not able to discriminate between /$\varepsilon$/ and /$\ae$/; (2) the Korean subjects, however, have difficulty producing a distinct version of these front vowels; and, (3) The relationship between the perception and production is not significant. These results were analyzed with the concept of "under-differentiation" and "reinterpretation of distinction," as well as how phonetic differences influenced the production and discrimination of front vowels by Korean speakers.

• Phonetics and Speech Sciences
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• v.6 no.1
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• pp.39-45
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• 2014

This study investigates twenty four Korean females' production of English front vowels focusing on the distinction in /i/ vs /ɪ/ and /ɛ/ vs /${\ae}$/ and formant values of stressed and unstressed vowels compared with those of native English speakers. The Korean learners were asked to read a textbook passage which includes ten sentences including target vowels. The major results indicate that: (1) Korean learners have trouble producing a distinct version (tense and lax) of front vowels in the paragraph reading; (2) The vowel space of the stressed vowels in a paragraph is smaller than that of embedded sentences; and (3) The vowel quality of the unstressed vowels produced by the Korean learners is similar to that of the native English speakers. The findings from this study can be applied to the pronunciation teaching for the Korean learners of English vowels and realization of English stress.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.99-107
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• 2013

The purpose of this study is to examine the relative distances among English front vowels in a message produced by 47 Korean and American speakers in order to better instruct pronunciation skills of English vowels for Korean English learners. A Praat script was developed to collect the first and second formant values(F1 and F2) of eight words in each sound file which was recorded from an internet speech archive. Then, the Euclidean distances were measured between the three vowel pairs: [i-ɛ], [i-ɪ], and [ɛ-æ]. The first vowel pair [i-ɛ] was set as the reference from which the relative distances of the other two vowel pairs were measured in percent in order to compare the vowel sounds among speakers of different vocal tract lengths. Results show that F1 values of the front vowels produced by the Korean and American speakers increased from the high front vowel to the low front vowel wih differences among the groups. The Korean speakers generally produced the front vowels with smaller jaw openings than the American speakers did. Secondly, the relative distance of the high front vowel pair [i-ɪ] showed a significant difference between the Korean and American speakers while that of the low front vowel pair [ɛ-æ] showed a non-significant difference. Finally, the Korean speakers in the higher proficiency level produced front vowels with higher F1 values than those in the lower proficiency level. The author concluded that Korean speakers should produce the front high vowels distinctively by securing sufficient relative distance of the formant values. Further studies would be desirable to examine how strong the Korean speakers' English proficiency correlate with the relative distance of target words of comparable productions.

• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.53-61
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• 2011

The present work is a follow-up study to that of Han, Choi, Lim and Lee (2011), where an asymmetry in the source segments eliciting the interlanguage speech intelligibility benefit (ISIB) was found such that the vowels which did not match any vowel of the Korean language were likely to elicit more ISIB than matched vowels. In order to identify the source of the stronger ISIB in non-matched vowels, acoustic analyses of the stimuli were performed. Two pairs of English front vowels [i] vs. [I], and $[{\varepsilon}]$ vs. $[{\ae}]$ were recorded by English native talkers and two groups of Korean learners according to their English proficiency, and then their vowel duration and the frequencies of the first two formants (F1, F2) were measured. The results demonstrated that the non-matched vowels such as [I], and $[{\ae}]$ produced by Korean talkers seemed to show more deviated acoustic characteristics from those of the natives, with longer duration and with closer formant values to the matched vowels, [i] and $[{\varepsilon}]$, than those of the English natives. Combining the results of acoustic measurements in the present study and those of word identification in Han et al. (2011), we suggest that relatively better performance in word identification by Korean talkers/listeners than the native English talkers/listeners is associated with the shared interlanguage of Korean talkers and listeners.

• Phonetics and Speech Sciences
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• v.1 no.4
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• pp.39-46
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• 2009

This study compares the perception of English high tense and lax vowels (/i, I, u, $\mho$/) by English speakers and Korean speakers of English. The four vowels were produced in /hVd/ context by a native speaker of English, and each word's vowel duration was manipulated to range from 170ms to 290ms in 30ms increments. Two English speakers and six Korean speakers of English were asked to listen to pairs of tense and lax vowel words with manipulated vowel durations and to identify the pair by choosing either heed-hid or hid-heed for front vowels and either who'd-hood or hood-who'd for back vowels. The results show that English speakers distinguished tense vowels from lax vowels with 100% accuracy regardless of the different durations, compared to 62% accuracy for Korean speakers of English. Most errors occurred for lengthened lax vowels and shortened tense vowels. The results of this study demonstrate that Korean speakers mainly rely on vowel duration as a cue to discriminate the tense and lax vowels. The theoretical and pedagogical implications of this finding are discussed.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.65-72
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• 2009

Formant values are the most important acoustic correlates of English vowels. Classical studies on English vowels reported the first three formant values measured at a single timepoint on a sustained vowel segment. However, many recent studies revealed that partial onset or offset segments with information of dynamic spectral changes may contribute to the exact identification of English vowels with an accuracy almost comparable to that by the whole vowel segment or word. The purpose of this study was to examine formant trajectories of nine English vowels collected by Hillenbrand et al.(1995). Acoustic analysis was systematically made by a Praat script at six equidistant timepoints over the vowel segment. Results showed that the first formant trajectories played an important role in distinguishing each vowel within the front- or back-vowel groups. The second formant trajectories of the back vowels varied more drastically than those of the front vowels. The third formant value was similar except the high vowel /i/. From the vowel space on F1 by F2 axes, the formant trajectories of each vowel clearly showed a transition toward the locus of the following consonant /d/. Other acoustic data revealed that there were some vowel inherent duration or pitch values. From this study we can conclude that the dynamic spectral changes are very important in specifying acoustic characteristics of the English vowels. Further studies on vowels and diphthongs in different contexts are desirable.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.21-29
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• 2013

The mismatch negativity (MMN) is known to be a fronto-centrally negative component of the auditory event-related potentials (ERP). $N\ddot{a}\ddot{a}t\ddot{a}nen$ et al. (1997) and Winkler et al. (1999) discuss that MMN acts as a cue to a phoneme perception in the ERP paradigm. In this study a perception experiment based on an ERP paradigm to check how Korean and American English speakers perceive the American English high front vowels was conducted. The study found that the MMN obtained from both Korean and American English speakers was shown around the same time after they heard F1s of English high front vowels. However, when the same groups heard English words containing them, the American English listeners' MMN was shown to be a little faster than the Korean listeners' MMN. These findings suggest that non-speech sounds, such as F1s of vowels, may be processed similarly across speakers of different languages; however, phonemes are processed differently; a native language phoneme is processed faster than a non-native language phoneme.

• Speech Sciences
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• v.8 no.4
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• pp.193-206
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• 2001

The purpose of this experimental study was to investigate characteristics of English vowels uttered by Korean regional dialect speakers. Ten English mono-syllabic words, and eight Korean mono-syllabic words, were uttered six times by nine female graduate students from three areas: Seoul, Yongnam and Honam. Formant frequencies were measured from sound spectrograms made by the PC Quirer. Results showed that Seoul dialect speakers uttered English vowels more similar to those uttered by English native speakers than did the other dialect speakers. In particular, Yongnam dialect speakers have articulatory problems pronouncing the back vowels(/u/, /$\upsilon$/, /c/), while Honam dialect speakers have problems pronouncing the front vowels(/i/. /I/, /$\varepsilon$/, /$\ae$/). Even though each group has different problems pronouncing English vowels, Korean speakers generally have difficulty in discriminating tense vowels(/i/ and /u/) from the lax vowels(/I/ and /$\upsilon$/). It appears that the width of Korean speakers' articulatory movements is comparatively narrower than those of native English speakers.

• Phonetics and Speech Sciences
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• v.5 no.2
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• pp.53-58
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• 2013

The purpose of this study is to compare the first two vowel formants of the stressed and unstressed English vowels produced by ten young males (in their twenties and thirties) and ten old males (in their forties or fifties) from the Buckeye Corpus of Conversational Speech. The results indicate that the stressed and unstressed vowels, /i/ and $/{\ae}/$ in particular, from the two groups are different in their formant frequencies. In addition, the vowel space of the unstressed vowels is somewhat smaller than that of the stressed vowels. Specifically, the range of the second formant of the unstressed vowels and that of the first formant of the unstressed front vowels were compressed. The findings from this study can be applied to the pronunciation training for the Korean learners of English vowels. We propose that teachers of English pay attention to the stress patterns of English vowels as well as their formant frequencies.