• Phonetics and Speech Sciences
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• v.1 no.4
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• pp.11-15
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• 2009

The aim of this study was to identify production difficulties of Korean learners of English in their articulation of English bilabial stops /p, b/ and labiodental fricatives /f, v/. Sixty non-sense syllables and twelve words were produced three times by nine graduate students. Test scores were measured from the score board made by FluSpeak, a speech training software program, which was designed for English pronunciation practice and improvement. Results show that 1) the subjects had lower scores in producing /p, b/ than /f, v/ from all positions, and 2) subjects had lower scores in medial (inter-vocalic) position than in initial (pre-vocalic) position and in final (post-vocalic) position when they produced /p/, /b/, /f/, and /v/. The results suggest that on the whole, Korean learners of English have much difficulty in producing /b/ and that they also have more articulatory problems in intervocalic than in the other positions when they produce these bilabial stops and labiodental fricatives.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.7 no.1
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• pp.50-55
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• 1996

Acoustic analysis study was performed on 20 normal subjects by speaking nonsense syllables composed of Korean bilabial stops$(/P, P^{\star}, P^{h}/)$ and their preceding and/or following vowel /a/ (that is, $[pa, p^{\star}a, p^{h}a, apa, ap^{\star}a, ap^{h}a]$) with an ultraminiature pressure, sensor. in their mouths. Speech materials were phonated twice, once with a moderate voice, another time with a loud voice. The acoustic signal and intraoral pressure were recorded simultaneously on computer. By these procedures, we were to measure the intraoral pressure, closure duration and VOT of Korean bilabial stops, and to compare the values one another according to the intensity of phonation and the position of the target consonants. Intraoral pressure was measured by the peak intraoral pressure value of Its wave closure duration by the time interval between the onset of intraoral pressure build-up and the burst meaning the release of closure ; Voice onset time(VOT) on by the time interval between the burst and the onset or glottal vibration. Heavily aspirated bilabial stop consonant /$p^h$/ showed the highest intraoral pressure value, unaspirated /$p^{\star}$/, the second, slightly aspirated /P/, the lowest. The syllable initial bilabial stops showed higher intraoral pressure than word initial stops, and the value of loudly phonated consonants were higher than moderate consonants. The longest closure duration period was that of /$p^{\star}$/ and the shortest, /P/, and the duration was longer in word initial position and in the moderate voice. In VOT, the order of the longest to shortest was $/{p^h}/, /p/, /{p^\star}/$, and the value was shorer when the consonant was in intervocalic position and when it was phonated with a loud voice.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.390-398
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• 1996

Acoustic analysis study was performed on 20 normal subjects by speaking nonsense syllables composed of Korean bilabial stops(/p, $p^{*}$/, ph/) and their Preceding and/or following vowel /a/(that is, [pa, $p^{*}a$, pha, apa, $ap^{*}a$, apha]) with an ultraminiature pressure sensor in their mouths. Speech materials were phonated twice, once with a moderate voice, another time with a loud voice. The acoustic signal and intraoral pressure were recorded simultaneously on computer. By these procedures, we were to measure the intraoral pressure, closure duration and VOT of Korean bilabial stops, and to compare the values one another according to the intensity of phonation and the position of the target consonants. Intraoral pressure was measured by the peak intraoral pressure value of its wave; closure duration by the time interval between the onset of intraoral pressure build-up and the burst meaning the release of closure; Voice onset time(VOT) by the time interval between the burst and the onset of glottal vibration. Heavily aspirated bilabial stop consonant /ph/ showed the highest intraoral pressure value, unaspirated /p$^{*}$/, the second, slightly aspirated /p/, the lowest. The syllable initial bilabial stops showed higher intraoral pressure than word initial stops, and the value of loudly phonated consonants were higher than moderate consonants. The longest closure duration period was that of /$p^{*}$/ and the shortest, /p/, and the duration was longer in word initial position and in the moderate voice. In VOT, the order of the longest to shortest was /ph/, /p/, /$p^{*}$/, and the value was shorter when the consonant was in intervocalic position and when it was phonated with a loud voice.

• Speech Sciences
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• v.12 no.3
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• pp.153-164
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• 2005

Two identical experiments are conducted at a six month interval in order to examine the VOT and its effect on the whole syllable duration or the rest portion of the syllable in Busan Korean. Just like the general characteristics of VOT, the aspirated stops consistently exhibit the longest VOT while tense stops have the shortest VOT. However, alveolar stops exhibit shorter VOT than labial stops, and it is contrary to the previous studies which claim that VOT values of labial stops are shorter than VOT values of alveolar stops. Moreover, there is a relationship between VOT and syllable/VC duration across stops. While VOT and syllable/VC duration have symmetric relationship for the aspirated velar and bilabial stops, other lax and tense stops exhibit the inverse relationship between the VOT and syllable/VC duration.

• Speech Sciences
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• v.9 no.3
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• pp.143-153
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• 2002

This study was designed to determine (1) the effects of the following stop consonant on the vowel length in isolated bi-syllabic words, (2) the mechanism which renders vowels longer in duration before lax stops than tense stops, (3) where the aspiratory interval is included, in the vowel portion or the preceding consonantal portion and (4) the influence of the preceding consonants upon the duration of the following vowel. Measurements were made of five timing variables on acoustic signals as three native Korean speakers uttered isolated bi-syllabic /VCV/ words in which the vowel was identical, /$\alpha$/, and the C slot was filled with bilabial stops. Findings: (1) the vowel length before the lax stops was significantly longer than before the tense stops, while the difference in the vowel duration between the tense stops was insignificant or negligible, (2) the vowel length varied as a function of the articulatory force of the following consonants, regardless of the phonological unit of syllable, (3) The aspiratory interval is interpreted as a portion of the preceding consonant and (4) The effects of the preceding consonants on the final vowel length were not rule-governed.

• Speech Sciences
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• v.12 no.3
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• pp.201-209
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• 2005

This study was investigated developmental temporal features in Putonghua-speaking children. The total of 212 children between the ages 2;6 and 6;5 participated in Shanghai. Speech materials were constructed according to aspiration feature in stop sounds of Putonghua. Six words were selected in this study. A voice onset time was measured. Non-parametric procedures were employed for all the analyses. The VOT value across bilabial, alveolar, and velar stops was significantly differed between aspirated and unaspirated stops for each age group. Effect of age is. significant for unaspirated stops. It is clear that each of Putonghua stops showed decreasing mean and standard deviation. The overshoot phenomenon of VOT was apparent from the age of 2;6-2;11 to 4;6-4;11. There was high variability in the production of lag time for aspirated stops.

• Proceedings of the KSPS conference
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• 2003.10a
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• pp.43-49
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• 2003

This study reveals the perceptual role of stop release burst to Koreans' recognition of POA(place of articulation) and voicing in the English word-final stops. 10 Korean subjects participated in a perception experiment wherein the stimuli are prepared on the basis of the amount of acoustic information, which includes the release burst. The result shows that i) release burst plays an important role in the recognition of POA in the order of velar, alveolar, and bilabial stops, and ii) the release burst more enhances the correct recognition of voiceless stops than that of voiced stops. This result leads us to conclude that the role of stop release burst differs with respect to the POA and voicing of the stops, and it is possibly related to the different intensity of release in voicing and in each POA.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.11-17
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• 2022

This study investigates closure durations of Korean stops in terms of laryngeal contrasts, places of articulation, and three positions within words. Twenty-two Korean speakers produced the nonsense words containing Korean stops found in word-initial and word-final positions and between vowels. The statistical results showed that the closure durations differed significantly by laryngeal contrast and place of articulation. In addition, the differences by position within words were marginally significant. The closure durations were in the order of lenis < aspirated < fortis stops by laryngeal contrast, velar < alveolar < bilabial stops by place of articulation, and word-final < word-initial < between vowels by positions within words. The laryngeal contrasts were neutralized in word-final position as per coda neutralization in Korean phonology. This study shows that closure durations should be considered a valuable phonetic cue to identify stops on par with voice onset time and f0.

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.3-11
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• 2015

This study compared English and Korean speakers with regard to the nasalization of the English stops /b, d, g, p, t, k/before a nasal within and across a word boundary. Nine English and thirty Korean speakers participated in the experiment. We used 37 speech items with different grammatical structures. Overall the English informants rarely nasalized the stops while the Korean informants generally greatly nasalized them though widely varying from no nasalization to almost complete nasalization. In general, voiced stops were more likely to be nasalized than voiceless stops. Also, the alveolar stops /d, t/tended to be nasalized the most, the bilabial stops /b, p/ the second most, and the velar stops /g, k/ the least. Besides, the closer the grammatical relationship between neighboring words, the more likely the stop nasalization occurred. In contrast, the Korean syllabification - the addition of the vowel /i/ to the final stops - worked against the stop nasalization. On the other hand, different stress (accent) or rhythm effects of the two languages are assumed to contribute to the significantly different nasalization between English and Korean speakers. The spectrum of stop nasalization obtained from this study can be used as an index to measure how close a certain Korean speaker's stop nasalization is to English speakers'.

• 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.