• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.81-89
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• 2014

Korean English learners tend to have difficulty perceiving and producing English vowels. The purpose of this study is to examine a link between perceived and produced vowel spaces of Korean learners of English. Sixteen Korean male and female participants perceived two sets of English synthetic vowels on a computer monitor and rated their naturalness. The same participants produced English vowels in a carrier sentence with high and low pitch variation in a clear speaking mode. The author compared the perceived and produced vowel spaces in terms of the pitch and gender variables. Results showed that the perceived vowel spaces were not significantly different in either variables. Korean learners perceived the vowels similarly. They did not differentiate the tense-lax vowel pairs nor the low vowels. Secondly, the produced vowel spaces of the male and female groups showed a 25% difference which may have come from their physiological differences in the vocal tract length. Thirdly, the comparison of the perceived and produced vowel spaces revealed that although the vowel space patterns of the Korean male and female learners appeared similar, which may lead to a relative link between perception and production, statistical differences existed in some vowels because of the acoustical properties of the synthetic vowels, which may lead to an independent link. The author concluded that any comparison between the perceived and produced vowel space of nonnative speakers should be made cautiously. Further studies would be desirable to examine how Koreans would perceive different sets of synthetic vowels.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.185-192
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• 2010

The acoustic vowel space has been used as an acoustic parameter in dysarthric speech. The aim of this work was to examine mathematical formulae for acoustic vowel space and to apply these to Korean speakers with idiopathic Parkinson's disease(IPD). Five acoustic parameters were chosen from earlier works and one new parameter was proposed, the pentagonal vowel space. The six parameters included triangular vowel space (3 area), irregular quadrilateral vowel space (4 area), irregular pentagonal vowel space (5 area), vowel articulatory index (VAI), formant centralization ratio (FCR) and F2i/F1u ratio (F2 ratio). An experimental group of 32 IPD patients(male:female=16:16) and a control group of twenty healthy people (male:female=8:12) participated in the study and repeated vowels (/a-i-u-e-o/) three times. A correlation analysis was performed among the six parameters, 2-way ANOVA was done with gender and groups as independent factors, and an independent sample t-test was conducted between the male and the female group as post hoc comparison. All parameters were highly correlated with each other and only the FCR showed a high negative correlation with the others. The results of ANOVA showed a significant difference in F2 ratio, 3 area, 4 area and 5 area between gender and in 4 area and 5 area between groups. For the male members of the two groups, significant statistical differences were found in all parameters whereas no such differences were found for the female members. These findings indicated that the vowel space of the female group was wider than the vowel space of the male group. These differences may have been caused by gender-specific speech styles rather than by patho-physiological mechanisms. We also claim that the pentagonal vowel space is better than the other vowel spaces at representing the disordered speech in natural speech situations.

• MALSORI
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• no.33_34
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• pp.111-125
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• 1997

This experimental phonetic analysis aims to describe standard Korean simple vowels with a view to presenting the vowel quality change from generation to generation, especially between the 50's and the 20's. This change reflects that the contemporary vowel system has both stable and unstable aspect: the former can be affirmed in the vowels with extreme positions in the vowel quadrilateral. and the latter in some vowels(e.g.,'ㅔ/ㅐ') which have the non-quantal vowel characteristics in the current vowel system. Formant values are measured to show these. And the results of acoustic analysis are presented graphically in the vowel quadrilateral for the convenience' sake. The comparison between the articulatory vowel quadrilateral and the acoustic one shows a lot concerning the current vowel quality change.

• Speech Sciences
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• v.13 no.4
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• pp.69-87
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• 2006

This study aims to describe the vowel system of present-day American English and to discuss some of its phonetic variations due to regional differences. Fifteen speakers of American English from various regions of the United States produced the monophthongs of English. The vowel duration and the frequencies of the first and the second formant were measured. The results indicate that the distinction between the vowels [c] and [a] has been merged in most parts of the U.S. except in some speakers from eastern and southeastern parts of the U.S., resulting in the general loss of phonemic distinction between the vowels. The phonemic merger of the two vowels can be interpreted as the result of the relatively small functional load of the [c]-[a] contrast, and the smaller back vowel space in comparison to the front vowel space. The study also shows that the F2 frequencies of the high back vowel [u] were extremely high in most of the speakers from the eastern region of the U.S., resulting in the overall reduction of their acoustic space for high vowels. From the viewpoint of the Adaptive Dispersion Theory proposed by Liljencrants & Lindblom (1972) and Lindblom (1986), the high back vowel [u] appeared to have been fronted in order to satisfy the economy of articulatory gesture to some extent without blurring any contrast between [i] and [u] in the high vowel region.

• Speech Sciences
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• v.10 no.2
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• pp.287-301
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• 2003

The purpose of this study was to examine whether the same vowel sounds are perceived differently by the two local dialect speakers, Seoul dialect speakers (SDS) and Kyungnam dialect speakers (KDS), whose vowel systems differ each other. In the first experiment SDS and KDS heard vowels synthesized in vowel space with F1 by F2 and categorized them into one of 10 Korean monophthongs. The results showed that SDS and KDS perceived the synthesized vowels differently. For example, /$\varepsilon$ versus /e/ contrast, ${\o}$/, and /y/ are differentiated by SDS, whereas they are perceptually confused by KDS. We also observed that /i/ could not be perceived unless the vowel synthesis included F3 or higher formants. In the second experiment SDS and KDS performed the similarity rating task of 10 synthesized Korean monophthongs. Two-dimensional MDS solution based on the similarity rating scores was obtained for each dialect group. The first dimension can be named 'vowel advancement' and the second 'vowel height'. The comparison of the two MDS solutions showed that the overall psychological distances among the vowels are shorter in KDS than SDS and that especially the distance between /$\Lambda$/ and /i/ is shorter in KDS than SDS. The result suggested that perception or mental representation of vowels depends on the vowel system of the listener's dialect or language. Further research problems were discussed in the final section.

• Phonetics and Speech Sciences
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• v.7 no.2
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• pp.95-102
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• 2015

The purpose of this paper is to extract the vowel formants of the ten adult male speakers in their twenties and thirties from the Korean Corpus of Spontaneous Speech [4], also known as the Seoul corpus, and to analyze them by comparing to earlier works on the Buckeye Corpus of Conversational Speech [1] in terms of the various linguistic factors that are expected to affect the formant distribution. The vowels extracted from the Korean corpus were also compared to those of the read Korean. The results showed that the distribution of the vowel formants from the Korean corpus was very different from that of read Korean speech. The comparison with English corpus and read English speech showed similar patterns. The factors affecting the Korean vowel formants were the interviewer sex, the location of the target vowel or the syllable containing it with respect to the phrasal word or utterance and the speech rate of the surrounding words.

• Phonetics and Speech Sciences
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• v.16 no.3
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• pp.7-23
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• 2024

Previous studies have highlighted the linguistic divergence between North and South Korean varieties. Although acoustic differences between North and South Korean in vowel production have been prominently observed, the vowel production in the standard varieties of Pyongyang North Korean (NK) and Seoul South Korean (SK) has had limited investigation. This study aims to explore the phonetic differences in vowel production between NK and SK speakers across two speech styles: careful and conversational speech. We analyzed a total of 13,370 vowels from each of 22 younger NK and SK speakers (16 females and 6 males in each group). Our findings reveal significant differences in the production of the vowels [æ], [ʌ], and [o] between the two varieties. Specifically, NK speakers maintained a distinction in height between the [e]-[æ] pair, a contrast that was not observed among SK speakers. Additionally, in NK, the [ʌ]-[o] pair showed considerable overlap (vowel merger) in both height and backness dimensions. These results shed light on the phonetic divergence between NK and SK varieties, offering insights into the acoustic features of NK vowel production. In further study, this understanding is crucial for supporting adaptation of NK refugees from the perspective of second dialect acquisition in South Korea.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.183-186
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• 2007

This study analyzes Korean high school students' pronunciation errors in word-initial onglides in English. For this study, 24 Korean high school students read 34 English words including glide-vowel sequences in word-initial positions and vowel-initial words in a frame sentence. The results showed 2 different error types: glide deletion and vowel distortion. After the analysis of the first recording, the subjects were taught how to pronounce glide-vowel sequences properly in a 60-minute class. Comparison of the analyses of the first and second recordings showed that the subjects improved on the pronunciation of glide-vowel sequences. After the training, the pronunciation errors of diphthongs unique to English, [$j_I$], decreased substantially. However, most subjects still had difficulties in pronouncing [$w{\mho}$], [wu], and [wo]. There was no significant correlation between English course grade and error reduction.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.165-169
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• 2014

Intelligibility of speech transmitted to listeners can significantly be degraded in noisy environments such as in auditorium and in train station due to ambient noises. Noise-masked speech signal is hard to be recognized by listeners. Among the conventional methods to improve speech intelligibility, consonant-vowel intensity ratio (CVR) approach reinforces the powers of overall consonants. However, excessively reinforced consonant is not helpful in recognition. Furthermore, only some of consonants are improved by the CVR approach. In this paper, we propose the corrective weighting (CW) approach that reinforces the powers of consonants according to syllable-type such as consonant-vowel-consonant (CVC), consonant-vowel (CV) and vowel-consonant (VC) in Korean differently, considering the level of listeners' recognition. The proposed CW approach was evaluated by the subjective test, Comparison Category Rating (CCR) test of ITU-T P.800, showed better performance, that is, 0.18 and 0.24 higher than the unprocessed CVR approach, respectively.

• Speech Sciences
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• v.8 no.4
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• pp.171-184
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• 2001

American English vowels and Korean vowels were compared by the plotformant method. For American English vowels, six General American English speakers pronounced English words in the b_t environment. For Korean vowels eight Kyongsang dialect speakers and eight Seoul dialect speakers pronounced Korean words in the environments of k_t, p_t and t_t. The formant plots were obtained by plotting F1/F2 tokens of 13 American English vowels on the F1xF2 plane. In spite of personal variations the 13 vowel spaces of all six American English speakers maintained their relative positions with some overlaps. Clear distinctions were made between i-I, e-$\varepsilon$, u-$\sigma$, and o-c. The domain of c and $\alpha$ overlapped for three American English speakers, but it did not for three other speakers. The 8 Korean vowel spaces of Kyongsang dialect speakers and Seoul dialect speakers were very similar and maintained their relative positions. No distinction was made between e and $\varepsilon$. In contrast with American English e which is a neutral vowel, Korean e was a back vowel. The comparison of 13 American English vowel positions and 8 Korean Vowel positions is expected to shed some light on the errors of English vowel pronunciation of Korean learners.