• 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.

• 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.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.2
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• pp.81-90
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• 2013

The purposes of this study are to: (1) Compare the vowel production of English front vowels produced by Korean speakers using regional dialects and; (2) Investigate and compare the effectiveness of pronunciation training for each regional dialect group. To test these objectives, the English front vowels produced by five Youngnam dialect male speakers, five Youngnam dialect female speakers, five Kangwon dialect male speakers, and five Kangwon dialect female speakers were scrutinized. These dialect groups' vowel formants and length of English front vowels were evaluated, and the post-pronunciation training values were compared with those of pre-training values. The results indicate that pronunciation training is more effective for Youngnam dialect speakers, whilst both dialect groups have more success mastering the pronunciation of /${\varepsilon}$/ over /${\ae}$/.

• Phonetics and Speech Sciences
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• v.9 no.2
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• pp.1-7
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• 2017

The purpose of this study is to investigate the relations between phonetic differences among Korean learners' production of English front vowels, pronunciation intelligibility and speaking proficiency test score. To do so, thirty Korean university students were asked (1) to read English text book paragraphs and (2) describe a picture. Two English native raters and one Korean rater evaluated Korean subjects' English pronunciation intelligibility and speaking. In addition, subjects' English vowel productions were acoustically analyzed(F0, F1, F2, vowel duration, intensity). The results of the study show that the vowel quality and pitch of the unstressed vowels and lax vowel are related to the pronunciation intelligibility. In addition, the scores of pronunciation intelligibility and speaking are highly related.

• 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.

• Journal of Digital Contents Society
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• v.13 no.3
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• pp.279-290
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• 2012

The purpose of this experimental study is to investigate and compare the vowel lengths of the English diphthongs, /eɪ/ and /aɪ/, and the front low vowel /æ/ among English-speaking natives with Korean college students using the Praat software program. To do this English sentences were uttered and recorded by twelve subjects, six Korean subjects and six English-speaking native subjects. All the subjects are female and their age ranges from 23 to 35. Acoustic features(duration) were measured from a sound spectrogram with the help of the Praat software program and analyzed through statistical analysis. Results showed that the vowel lengths of the English diphthongs and the front low vowel between native English speakers and Korean collegians were different. In the pronunciation of the diphthongs /eɪ/ and /aɪ/, Korean subjects pronounced longer than native subjects did, but the difference was not significant. However, in the pronunciation of the English front low vowel /æ/, native subjects pronounced significantly longer than Korean subjects did. From the data of the overall sum of words and vowels between the two subject groups, we were able to find out that the differences of lengths of both the three words and the two diphthongs /eɪ/ and /aɪ/ were not significant, but those of /æ/ were significant.

• The Journal of the Acoustical Society of Korea
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• v.8 no.4
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• pp.65-73
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• 1989

In this paper, we propose a text-independent speaker identification algorithm based on VQ(vector quantization) and vowel classification, and its performance is studied and compared with that of a conventional speaker identification algorithm using VQ. The proposed speaker identification algorithm is composed of three processes: vowel segmentation, vowel recognition and average distortion calculation. The vowel segmentation is performed automatlcally using RMS energy, BTR(Back-to-Total cavity volume Ratio)and SFBR(Signed Front-to-Back maximum area Ratio) extracted from input speech signal. If the Input speech signal Is noisy, particularity when the SNR is around 20dB, the proposed speaker identification algorithm performs better than the reference speaker identification algorithm when the correct vowel segmentation is done. The same result is obtained when we use the noisy telephone speech signal as an input, too.

• Speech Sciences
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• v.5 no.2
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• pp.41-55
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• 1999

This paper aims to acoustically analyze the merger of back vowels in North Korean dialects which I believe, are here investigated for the first time since 1945. North Korean back vowels are distinctive from South Korean back vowels because they merge mainly on the back vowel space, while front vowels merge mainly in Seoul standard language and other South Korean dialects. In this paper the future of the vowel systems caused by the merger of the vowels in Korean dialects will also be investigated. North Korean dialects examined include dialects of the Pyungan, the Hamkyung, and the Hwanghae Provinces. North Korean back vowels are distinctive from South Korean back vowels because they merge mainly on the back vowel space, while front vowels merge mainly in Seoul standard language and other South Korean dialects.

• Phonetics and Speech Sciences
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• v.1 no.2
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• pp.95-103
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• 2009

We investigated the perceptual structure of Korean consonants by analyzing the confusion among consonants in various vowel contexts. The 36 CV syllable types combined by 18 consonants and 2 vowels (/i/ and /u/) were presented with masking noises or in degraded intensity. The confusion data were analyzed by the INDSCAL (Individual Difference Scaling), ADCLUS (Additive Clustering) and the probability of the transmitted information. The results were compared with those of a previous study with /a/ vowel context (Bae and Kim, 2002). The overall results showed that the laryngeal features-aspiration, lax and tense-are the most salient features in the perception of Korean consonant regardless of vowel contexts, but the perceptual saliency of place features varies across vowel conditions. In high vowel (front and back vowel) contexts, sibilant consonants were perceptually salient compared to in low vowel contexts. In back vowel contexts, grave (labial and velar) consonants were perceptually salient. These findings imply that place features and vowel features strongly interact in speech perception as well as in speech production. All statistical measures from our confusion data ensured that the perceptual structure of Korean consonants correspond to the hierarchical structure suggested in the feature geometry (Clements, 1991). We discuss the link between speech perception and production as the basis of phonology.