• Speech Sciences
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• v.7 no.4
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• pp.93-105
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• 2000

The English schwa sound has special characteristics which are distinct from other vowels. It is non-phonemic and occurs only in an unstressed syllable. Compared with the English schwa, the Korean /e/ is a full vowel which has phonemic contrast. This paper had three aims. One was to see whether there is any relationship between English full vowels and their reduced vowel schwas. Second was to see whether there is any possible target in the English schwa sounds which are derived from different full vowels. The third was to compare the English non-phoneme vowel schwa and the Korean full vowel /e/ in terms of articulatory positions and duration. The study results showed that there is no relationship between each of the full vowels and its schwa. The schwa tended to converge into a possible target which was F1 456 and F2 1560. The Korean vowel /e/ seemed to have its distinct position speaker-individual which is different from the neutral tongue position. The evidence that the Korean /e/ is a back vowel was supported by the Seoul dialect speaker. In duration, the English schwa was much shorter than the full vowels, but there was no significant difference in length between the Korean /e/ and other Korean vowels.

• Speech Sciences
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• v.12 no.4
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• pp.167-180
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• 2005

The present study examines the phonetic realizations of the unstressed weak vowel /e/ in English words produced by native and Korean ESL speakers. Traditionally, the stressed elements in utterance are considered to be prominent. In this sense, the unstressed weak vowel /e/ is predicted to be shorter in length, lower in pitch and intensity than the stressed vowels. The experiment shows that native English speakers correlate the unstressed weak vowel /e/ with both shorter duration and lower pitch; Korean ESL speakers correlate it with lower pitch only. We cannot find any significant statistical difference in intensity between /e/ and the stressed vowels in both cases. This study suggests it is important to acquire and produce the correct prosodic correlates of the unstressed weak vowel /e/ for Korean ESL speakers to command more natural English intonation, since /e/ is the most common vowel in English speech and consists of the English foot rhythm along with stressed vowels.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.53-69
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• 1996

Much research has been done on the rues differentiating the three Korean stops in word initial position. This paper focuses on a more neglected area: the acoustic cues differentiating the medial tense and lax unaspirated stops. Eight adult Korean native speakers, four males and four females, pronounced sixteen minimal pairs containing the two series of medial stops with different preceding vowel qualities. The average duration of vowels before lax stops is 31 msec longer than before their tense counterparts (70 msec for lax vs 39 msec for tense). In addition, the average duration of the stop closure of tense stops is 135 msec longer than that of lax stops (69 msec for lax vs 204msec for tense). THESE DURATIONAL DIFFERENCES ARE 50 LARGE THAT THEY MAY BE PHONOLOGICALLY DETERMINED, NOT PHONETICALLY. Moreover, vowel duration varies with the speaker's sex. Female speakers have 5 msec shorter vowel duration before both stops. The quality of voicing, tense or lax, is also a cue to these two stop types, as it is in initial position, but the relative duration of the stops appears to be much more important cues. The duration of stops changes the stop perception while that of preceding vowel does not. The consequences of these results for the phonological description of Korean as well as the synthesis and automatic recognition of Korean will be discussed.

• 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.

• Phonetics and Speech Sciences
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• v.4 no.4
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• pp.3-17
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• 2012

This study examines Korean speakers' production of English consonant clusters, focusing on vowel insertion. An acoustic analysis along with a statistical test was carried out to see what factors are involved in this production. The following factors were considered in the present study: phonetic properties, L1 transfer, and cluster types. Specifically, liquid types were considered to see if they cause any difference depending on C+/l/ or C+/r/ clusters in the onset in terms of vowel insertion patterns. That is, it was examined which Korean speakers produce better, C+/l/ or C+/r/ clusters. Interestingly, the result of the present experiment shows that the correct answer percent was higher in the C+/r/ onset clusters than C+/l/ onset clusters unlike Eckman's (1977) Marked Differential Hypothesis. In other words, the occurrence of the vowel insertion in C+/l/ clusters is higher than C+/r/ onset clusters. This may be attributed to L1 transfer. Furthermore, in the present study, three patterns of vowel insertion in the C+/l/ clusters were identified by implementing an acoustic analysis based on vowel duration and formant: a) vowel insertion with gemination, b) phonological epenthesis, and c) phonetic intrusion. However, phonetic intrusion mainly occurred in the C+/r/ clusters. Data were collected from 54 Korean speakers to see what factors are involved in vowel insertion patterns in the production of English consonant clusters. This study provides evidence for L1 transfer, the duration effect of /l/ in a different context, and three kinds of vowel insertion patterns in conjunction with gestural coordination by age groups.

• Phonetics and Speech Sciences
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• v.1 no.1
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• pp.41-46
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• 2009

Duration of the preceding vowel is known to vary as a function of the (phonological or phonetic) voicing feature of the following consonant. This study raises a question against this general belief. A spectrographic experiment using 14 Korean obstruents (three sets of stops: /p, p', $p^h$/, /t, t', $t^h$/, /k, k', $k^h$/; one set of affricates: /c, c', $c^h$/; one set of fricatives: /s, s'/) reveals that (1) phonetic voicing in the intervocalic lax consonants /p, t, k, c, s/ has nothing to do with the duration of the preceding vowel; (2) vowel length is significantly shorter before tense consonants than before their lax cognates while tense consonants are significantly longer than their lax cognates. Importantly, Korean obstruents are all phonologically voiceless. Therefore, the voicing feature is rejected as the cause of preconsonantal vowel shortening in Korean both phonetically and phonologically. It is suggested that the temporal phenomenon is basically a kind of physiologically-motivated coarticulation though it is restricted by the phonology of a given language. To meet this assumption, the feature voicing should be replaced with the feature tenseness as the cause, which will enable us to explain the temporal phenomenon on the same basis irrespective of language.

• 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.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.495-503
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• 2013

The purpose of this study was to investigate how Korean speakers produce English vowels. Twenty one Korean learners produced the vowels [i, ɪ, eɪ, ɛ, æ, ɑ, ʌ, ɔ, oʊ, ʊ, u] in bVt or pVt forms of real words. Acoustic measurements were conducted for the vowel formant frequencies (F1, F2) and duration. Results showed that Korean learners tended to produce the vowel duration longer than native English speakers. Also, the front vowels produced by Korean participants tended to be produced at the more frontal part of the tongue. In addition, Korean participants distinguished the tense and lax pairs not through quality(F1, F2) but through vowel duration. This is different from the native English speakers in that they differentiate tense and lax pairs by quality(F1, F2) as well as vowel duration. Based on these results, pedagogical implications are discussed.

• 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.2 no.3
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• pp.37-46
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• 2010

This study investigates acoustic characteristics of English and Korean voiceless sibilant fricatives as they appear before the three vowels, /i/, /$\alpha$/ and /u/. Three measurements - duration, center of gravity and major spectral peak - are employed to compare acoustic properties and vowel effect for each fricative sound. This study also investigates the question of whether Korean sibilant fricatives are acoustically similar to the English voiceless alveolar fricative /s/ or to the palato-alveolar /$\int$/. The results show that in the duration of frication noise, English /$\int$/ is the longest and Korean lax /s/ the shortest of the four sounds. It is also observed that English alveolar /s/ has the highest value, whereas Korean /s/ shows the lowest value in the frequency of center of gravity. In terms of major spectral peak, while English /s/ reveals the highest frequency, English /$\int$/ shows the lowest value. In addition, evidence indicates that there is a strong vowel effect in the fricative sounds of both languages, although the vowel effect patterns of the two languages are inconsistent. For instance, in the major spectral peak, both Korean lax /s/ and tense /$s^*$/ show significantly higher frequencies before the vowel /$\alpha$/ than before the other vowels, whereas both English /s/ and /$\int$/ exhibit significantly higher frequencies before the vowel /i/ than before the other vowels. These results indicate that Korean sibilant fricatives are acoustically distinct from both English /s/ and /$\int$/.