• 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.

• MALSORI
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• no.46
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• pp.13-24
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• 2003

This experimental study shows that, in reading of the English isolated words that are enumerated, the releasing of the word-final stop is employed for signaling enumeration in company with the well-known intonational pattern for it. Furthermore, this study tries to find the aspects of the releasing of the stops in the word-final positions, focusing on the association of the stop releasing/nonreleasing with i) the POA (Place of Articulation) distinction of the word-final stop, ii) the various qualities of the vowel before the final stop, and iii) the voice distinction of the stop in the word-final position.

• Speech Sciences
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• v.7 no.1
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• pp.109-141
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• 2000

Acoustic and aerodynamic characteristics of Cheju consonants were examined with the focus on the well-known three-way distinction among stops (i.e., lenis, fortis, aspirated) and the two-way distinction between sand s*. Acoustic parameters examined for the stops included VOT, relative stop burst energy, Fo at the vowel onset, H1-H2, and H1-F2 at the vowel onset. For the fricatives s and s*, acoustic parameters were fricative duration, Fo, centroid of the fricative noise, RMS energy of the frication, H1-H2 and Hl-F2 at the onset of the following vowel. In investigating aerodynamics, intraoral pressure and oral flow were included for the bilabial stops. Results indicate that, although Cheju and Korean are not mutually intelligible, acoustic and aerodynamic properties of Cheju consonants are very similar in every respect to those of the standard Korean. Among other findings there are three crucial points worth recapitulating. First, stops are systematically differentiated by the voice quality of the following vowel. Second, stops are also differentiated by aerodynamic mechanisms. The aspirated and fortis stops are similar in supralaryngeal articulation, but employ a different relation between intraoral pressure and flow. Finally, our study suggests that the fricative s is better categorized as 'lenis' than as 'aspirated' in terms of its phonetic realization.

• 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.

• MALSORI
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• no.33_34
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• pp.1-10
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• 1997

Korean stop consonants are well known for their tripple distinction. In word initial position lax, tense and aspirated consonants are all voiceless. They are differentiated by the degree of tension, aspiration and VOT(voice onset time). But in intervocalic position, lax consonants become voiced. In this study I compare the acoustic features of Korean intervocalic lax and tense stops. The closure duration of lax stops is shorter than that of tense consonants. The preceding vowel length is longer in tan than that in tense consonants. I modify the above acoustic characteristics by an experimental methods. For example, I shorten the closure duration of intervocalic tense stops by 5 steps. r also do auditory tests which will show us listener's reaction on the above examples. And do the same job with the preceding vowels. According to the auditory test, the closure duration does an important role in differentiating Korean intervocalic lax and tense stops. But the preceding vowel length has almost nothing to do with the distinction between lax and tense stops. So I conclude that acoustic features also have hierarchy. Some features have categorical characteristics and others don't.

• 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.

• Phonetics and Speech Sciences
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• v.3 no.4
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• pp.13-21
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• 2011

The present study investigated the effects of two different sources of prosodic strengthening, i.e., boundary and accent, in the articulation of English high front vowels, /i/ and /I/. The vowels were investigated in vowel-initial ('eat' vs. 'it'), /h/-initial ('heat' vs. 'hit') and /p/-initial words ('Pete' vs. 'pit'), which were placed in varying prosodic conditions. Using Electromagnetic Articulograph (EMA), the tongue dorsum positions in the x and y dimensions, the lip opening and the jaw opening (lowering) were measured. With respect to the boundary-induced strengthening, results showed that /i/ and /I/ in vowel-initial words ('eat' - 'it') are produced with a higher tongue position in the domain-intial than domain-medial positions. The fact that the vowels only in the vowel-initial condition showed the domain-intial strengthening (DIS) effect suggests that the DIS effect is localized mainly to the initial position (the locality account). As for the accent-induced strengthening, vowels were produced with a more fronted tongue position and larger lip opening in accented than unaccented positions. This suggests that the presence of accent increases overall sonority of the vowels in various prosodic contexts, and enhances primarily the frontedness of the front high vowels. Taken together, the results indicate that the two types of prosodic strengthening are articulatorily realized differently, supporting the view that they are encoded separately in the speech planning process. The present study also showed the distinction between the two high front vowels in the tongue position (in both the frontedness and the height dimensions), while the jaw did not seem to contribute to the distinction robustly, suggesting that the tongue contributes more in distinguishing the two vowels than the jaw does.

• MALSORI
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• no.56
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• pp.49-73
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• 2005

This study explores the most important temporal cues in the perception of the voiced/voiceless distinction of English plosives in terms of newly defined measures of perception: original signal to response agreement, unit signal to response agreement, and robustness. Seven native speakers of English and three leveled groups of Korean English learners participated in the present study. The results showed that both native speakers of English and Korean groups failed to successfully perceive the voiced/voiceless distinction of English plosives, particularly alveolar plosives, in word-medial trochaic positions. The results also showed that in word-initial and word-medial iambic positions both native speakers of English and Korean groups employ the information in the release burst and aspiration in the perception of the voiced/voiceless distinction, of English plosives, and that in word-final positions native speakers of English employ the information in the preceding vowel, while Korean groups employ the information in the closure interval.

• The Transactions of the Korea Information Processing Society
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• v.4 no.6
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• pp.1652-1663
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• 1997

This paper proposes a distinction algorithm of Korean and English characters which can be applied to multi-font from the results of thinning. The proposed algorithm distinguishes Korean and English characters as the number of connected components. If it can not distinguish those characters with the number of connected component, it distinguishes them as the vowel included in Korean characters. In experimental results, the distinction rate is about 99.82% for the 21,150 characters of three widely used fonts.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.12
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• pp.1324-1335
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• 1991

In this paper, a phoneme separation and an establishment of discriminative pattern of Korean phonemes are studied on experiment. The separation uses parameters such as pitch extraction, glottal peak pulse width of each pitch. speech duration. envelope and amplitude bias. The first pitch is extracted by deviations of glottal peak and width. energy and normalization on a bias on the top of vowel envelope. And then, it traces adjacent pitch to vowel in whole. On vewel, amethod to be reduced gliding pattern and the possible of vowel distinction to be used just second formant are proposed, and shrinking pitch waveform has nothing to do with pitch length is estimated. A pattern of envelope, spectrum, shrinking waveform, and a method of analysis by mutual relation among phonemes and manners of articulation on consonant are detected. As experimental results, 90% on vowel phoneme, 80% and 60% on initial and final consonant are discriminated.