• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.85-92
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• 2012

It is a well-known phenomenon that vowel duration in English is generally longer before a voiced stop than a voiceless one. Past research has postulated that the closure duration of the voiceless stop is generally longer than that of the voiced stop and that the duration of a preceding vowel is determined complementarily by the closure duration of the stop. To shed further light on the phenomenon, this study examined fourteen native speakers of American English who read the monosyllabic words [bVC] (V = [i, ɪ, eɪ, ɛ, æ, ʌ, ɑ], C = [t, d]). First, we found that mean vowel duration was 38 ms longer before the voiced stop than the voiceless (mean duration ratio = 1.24). Second, mean closure duration of the voiced stop was only shorter by 5 ms compared to the voiceless stop (mean duration ratio = 0.97). Therefore, for our subjects, vowel duration was not determined complementarily by the closure duration of the following stop. Third, vowels with longer inherent durations (viz., tense, diphthong, and low vowels) tended to show larger duration ratios in the voiced and voiceless contexts than the vowels with shorter durations (viz., lax vowels). This indicates that the lengthening of inherently shorter vowels before a voiced stop is limited in order to avoid overlapping with longer vowels in the duration range. Fourth, there was no significant gender difference in vowel duration ratios in the contexts of voiced and voiceless stops. Finally, considerable individual differences were found in the vowel and consonant duration ratios.

• Journal of the Korean Society of Tobacco Science
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• v.37 no.1
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• pp.8-17
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• 2015

The purpose of this study is to classify the tobacco names in the world, to investigate the regional distribution of the classified type, and to show origin of names according to the type. The names of tobacco used in this study was 50. The type of tobacco names was classified by the presence or absence of nasal sound(morn) on the first syllable, the Number of syllable, and the structure of consonants and vowels of tobacco names. Type I (Dambago) has the nasal sound on the first syllable. The proportion of Type I(Dambago) was 28%. And the rest(Type I~Type V ; 72%) has no nasal sound. Type II(Tabaco) has three syllables, and its proportion was 20%. Type III(Tabac) has the two syllables and the structure of T+vowels+B+vowels. And its proportion was 30%. Type IV(Tutun) has the two syllables and the structure of T+vowels+T+vowels. And its proportion was 12%. Type V(Duhan) has the two syllables and the structure of D+vowels+H(V)+vowels. And its proportion was 10%. The world's most widely distributed type was Type I(Dambago). regional distribution of the world's tobacco names were clustered by the type. 72% of Type I(Dambago) was distributed in Asia. The etymology of Type I(Dambago) was only 14% Tambaku and the other is not yet known. The etymology of Type I(Dambago) seems to be derived from the Haitian Tambaku(meaning a tobacco pipe). 88% of Type II(Tabaco) and III(Tabac) were distributed in Europe. The etymology of Type II(Tabaco) and Type III(Tabac) were 84% Spanish "Tabaco". 100% of Type IV(Tutun) and V(Duhan) were distributed in Europe. The etymology of Type IV(Tutun) and Type V(Duhan) were 100% Turkish tutun and duhan, respectively. This finding suggests that the etymology of Type I(Dambago) is certainly may be Haitian "Tambaku(meaning a tobacco pipe)".

• Korean Journal of Cognitive Science
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• v.15 no.1
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• pp.1-11
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• 2004

The aim of this study is to reveal the order and the age of mastery of phonemic contrast in vowel sounds of Korean. For this purpose, we made an observation of the correspondences between the sounds produced by children of 12-35 months and the target sounds produced by adults. The provisional order and the age of contrast acquisition shown from the results of this study are as follows. First, the differential production of vowels by the feature relating to the body of the tongue precedes the differential production of vowels by the feature relating to the lip rounding. Second, as for the differential production of vowels by the feature relating to the body of the tongue, the contrast between the low vowels and the others is accomplished first, and the contrast between the high and low vowels and the contrast between the front and the back vowels are established around the age of 24 months. Third, as for the differential production of vowels by the feature relating to the lip rounding, the contrast between the rounded and the unrounded vowel is not accomplished until 36 months. Finally, we observed, prior to the completion of the differential production of phonemes, children use a specific phoneme excessively. This passing phrase could be interpreted as a result of over-application of a distinctive feature in the course of acquisition of it.

• Phonetics and Speech Sciences
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• v.5 no.2
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• pp.33-41
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• 2013

This is a follow-up study on Han and Kang (2013) which argued that the Euclidean distances between /o/ and /u/ in Seoul Korean decreased in the first syllable position as speakers were among younger female speakers but not for male speakers, whereas in the second syllable position both gender groups showed a cross-generational decreasing effect of the Euclidean distance between /o/ and /u/. This study normalized the same data in Han and Kang (2013) which measured 12 speakers (six males and six females) for each Age group and investigated the spectral changes vowels /o/ and /u/ between age and gender, using the log-mean normalized statistical results. This study also examined overlap fraction values generated in SOAM 2D ($F1{\times}F2$) (cf. Wassink, 2006), which may also indicate the proximity of two vowels in question. The results showed that /o/ and /u/ vowels were making closer with /o/ raising for female speakers in $V_1$ and $V_2$ positions but only in the $V_2$ position for male speakers. That is, females led the upward movement of peripheral /o/ vowel, just like the raising of 'e' and 'o' in New York City (Labov, 1991). The results also showed that younger speakers used a rather narrow vowel space for the vowels. This also contributed to the proximity of the vowels /o/ and /u/, resulting in rather large overlap fraction values for younger speakers between these two vowels.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.2
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• pp.142-146
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• 1998

Background : It has been established that the fundamental frequency(Fo) of the vowels varies systemically as a function of vowel height. Specifically, high vowels have a higher Fo than low vowels. Two major explanations or hypotheses dominate contemporary accounts of fired to explain the mechanisms underlying intrinsic variation in vowel Fo, source-tract coupling hypothesis and tongue-pull hypothesis. Objectives : Total laryngectomy surgery necessiates removal of all structures between the hyoid bone and the tracheal rings. Therefore, the assumption that no direct interconnection exists between the tongue and pharyngoesophageal segment that would mediate systematic variation in vowel Fo appears quite reasonable. If tongue-pull hypothesis is correct, systemic differences in Fo between high versus low vowels produced by esophageal speakers would not Or expected. We analyzed the Fo in the vowels of esophageal voice. Materials and method : The subjects were 11 cases of laryngectomee patients with fluent esophageal voice. The five essential vowels were recorded and analyzed with computer speech analysis system(Computerized Speech Lab). The Fo was measured using acoustic waveform, automatically and manually, and narrow band spectral analysis. Results : The results of this study reveal that intrinsic variation in vowel Fo is clearly evident in esophageal speech. By analysis using acoustic waveform automatically, the signals were too irregular to measure the Fo precisely. So the data from automatic analysis of acoustic waveform is not logical. But the Fo by measuring with manually calculated acoustic waveform or narrowband spectral analysis resulted in acceptable results. These results were interpreted to support neither the source-tract coupling nor the tongue-pull hypotheses and led us to offer an alternative explanation to account for intrinsic variation of Fo.

• Speech Sciences
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• v.11 no.3
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• pp.55-68
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• 2004

The purpose of this experimental study is to investigate the relationship between English pronunciation and listening comprehension of English diphthongs and low vowels of Korean college students from the Chungnam and Gyungnam provinces. Of 22 test sentences for listening comprehension, 15 sentences were recorded by native speakers and seven sentences were edited from Springboard by Oxford University Press. For the listening comprehension test, 90 subjects from two groups, Chungnam dialect speakers and Gyungnam dialect speakers, were selected. They listened to 22 sentences produced by audio cassette tape and completed a cloze exercise. By the results of this experiment, we observed that Korean collegians of Gyungnam province showed a better listening comprehension of words including front low vowels when they preceded voiced sounds than those of Chungnam province. When the back low vowel came in an open syllable, we also recognized the same result; Gyungnam province collegians showed better listening comprehension of words including back low vowels than those of Chungnam province. As the results of Hee-Suk Park & Jung-Soak Kim(2003) showed that Gyungnam province collegians pronounced the English low vowels longer than Chungnam province collegians, we discovered that there was a positive relation between English pronunciation and listening comprehension, especially in Gyungnam province collegians. However regarding words including English diphthongs we discovered almost no relation between English pronunciation and listening comprehension.

• Phonetics and Speech Sciences
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• v.2 no.3
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• pp.75-80
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• 2010

The present research investigated the characteristics of voice between genders and nationalities by measuring the acoustic parameter values of Korean and Chinese students. Sound Forge was used to collect voice samples and Praat was used to measure and analyze jitter, shimmer, NHR, $sF_0$, and pitch range. The results of this research are a follows. First, during prolongation of the vowels, there was no significant difference in $F_0$ between Korean and Chinese males and Korean and Chinese females. Korean males and females had higher $F_0$ values than Chinese males and females. Secondly, during sentence reading, there was no significant difference between Korean and Chinese males in $sF_0$. But between female groups, there was a significant difference in $sF_0$. Thirdly, during sentence reading, the pitch range in Korean males was found to be narrower compared to Korean and Chinese females who had wider pitch range, showing a significant difference. Fourthly, jitter in the five vowels /a, i, u, e, o/ was found to be higher in Chinese than Korean subjects. In the vowels /a, e, u/ females were higher than males showing a significant difference. Fifthly, shimmer in the vowels /a, e, u/ was found to be higher in Chinese than Korean subjects showing a significant difference. Finally, NHR in the vowels /a, u, o/ was found to be higher in Chinese than Korean subjects showing a significant difference.

• Speech Sciences
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• v.4 no.1
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• pp.19-34
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• 1998

The author collected and compared midsagittal, coronal, coronal oblique, and transversal images of Korean monophthongs /a, i, e, o, u, i, v/ produced by a healthy male speaker using 1.5 T MR, VISION. Area was measured by computer software after tracing the cross-section at different points along the tract. Results showed that the width of the oral and pharyngeal cavities varied compensatorily from each other on the midsagittal dimension. Formant frequency values estimated from the area functions of the seven vowels showed a strong correlation (r=0.978) with those analyzed from the spoken vowels. Moreover, almost all of 35 students who listened to the synthesized vowels from area data perceived the synthesized vowels as equivalent to the spoken ones. Movement of constriction points of vowel /u/ with wider lip opening sounded /i/ and led to slight changes in vowel quality. Jaw and tongue movement led to major volume variation with an anatomical limitation. Each comer vowel varied systematically from a somewhat constant volume of the average area. Thus, the author proposed that any simulation studies related to vocal tract area variation should reflect its constant volume. The results may be helpful to verify exact measurement of the vocal tract area through vowel synthesis and a simulation study before having any operation of the vocal tract.

• Speech Sciences
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• v.7 no.1
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• pp.187-201
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• 2000

This study was done to investigate the English vowels in relation to the foreign accent. In this study, I also tried to find out the foreign accent of the English diphthong /o/ and front low vowel /${\ae}$/ when Koreans speak English. The reason why I chose these vowels is that these vowels, /o/ and /${\ae}$/, are difficult for Koreans to discern and pronounce. Koreans show a foreign accent in their pronunciation. In order to find out the reason for a Korean foreign accent, experiments were carried out with the help of acoustic instruments. According to the results of the experiment, Koreans showed a foreign accent in their English pronunciation of vowels in relation to their utterance positions. Americans showed a final lengthening effect but Koreans showed a final shortening effect. This means that Koreans showed a foreign accent in the final stressed syllable of a sentence. In addition to this, the duration of two English vowels, /o/ and /${\ae}$/, showed considerably different features between Koreans and Americans. In fact, in the pronunciation of the diphthong /o/, the tongue moves from one position to another. The two articulations of a diphthong can be described as the nucleus plus a glide. However, most Koreans have no idea of this phenomenon and pronounce the diphthongs like two separate monophthongs. This causes a great difference in the lengths of English diphthong /o/ between Koreans and Americans.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.39-46
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• 2013

This study examined the perception of two Korean vowels using F1/F2 manipulated synthetic vowels. Previous studies indicated that there is an overlap between the acoustic spaces of Korean /o/ and /u/ in terms of the first two formants. A continuum of eleven synthetic vowels were used as stimuli. The experiment consisted of three tasks: an /o/ identification task (Yes-no), an /u/ identification task (Yes-no), and a forced choice identification task (/o/-/u/). ROC(Receiver Operating Characteristic) analysis and logistic regression were performed to calculate the boundary criterion of the two vowels along the stimulus continuum, and to predict the perceptual judgment on F1 and F2. The result indicated that the location between stimulus no.5 (F1 = 342Hz, F2 = 691Hz) and no.6 (F1 = 336Hz, F2 = 700Hz) was estimated as a perceptual boundary region between /o/ and /u/, while stimulus no.0 (F1=405Hz, F2=666Hz) and no.10 (F1=321Hz, F2=743Hz) were at opposite ends of the continuum. The influence of F2 was predominant over F1 on the perception of the vowel categories.