• 대한음성학회지:말소리
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• 제45호
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• pp.1-14
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• 2003

This paper criticizes S. Kim (1992), claiming that the perception of place cues in the reduced stop consonant clusters ('reducing' means 'cutting off' the acoustic silence in stop clusters) largely depends on the acoustic characteristics such as formant transition and noise frequency distribution of stop burst, rather than the closure duration time as advocated by S. Kim (1992). The claim is based on the perception test conducted upon 111 stimuli over 10 subjects. The finding is that, when the closure duration is cut off up to the point where only one stop is perceived, place of the second stop, not the first one, in the cluster is in most cases perceived regardless of the places of the first and second stops. It is likely that the place cues of the stop in the prevocalic position mask those in the postvocalic position.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1996년도 10월 학술대회지
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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.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2005년도 추계 학술대회 발표논문집
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• pp.189-192
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• 2005

This study investigates the asymmetry effect between acoustics and perception. The examined cues are closure duration, closure voicing, VOT, release, pre-vowel duration, post-vowel duration. Five native speakers of English and 30 Korean college students participated in the present study. The results showed that high level Korean English learners parallels native speakers in their responses, while mid and low level Korean learners are substantially different from natives.

• 대한음성학회지:말소리
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• 제33_34호
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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.

• 대한음성학회지:말소리
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• 제47호
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• pp.31-49
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• 2003

This paper investigates phonation types of Malay plosives and compares Malay plosives with Korean ones in terms of VOT, F0, duration of closure, and durations of the preceding and following vowels. This study is significant in that it specifies phonetic characteristics of phonation types of the two languages and provides phonetic bases for teaching and learning either of the two languages. The results showed that Malay voiceless plosives are greater than voiced ones in VOT, F0, duration of closure, but the other way in durations of the preceding and following vowels. Comparison of the two languages, particularly in terms of the distribution of VOT, indicates that Malay voiceless plosives are close to Korean fortis plosives.

• Clinical and Experimental Pediatrics
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• 제53권4호
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• pp.579-584
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• 2010

목 적: 해외귀국학생들의 수가 매년 증가하고 있다. 이들은 우리말의 체계가 완전히 확립되기 전 다른 언어의 영향을 받고 성장하여 우리말의 이해가 어렵고, 발음이 어눌하여 학업이나 교우관계에 문제가 발생하게 된다. 본 연구는 해외귀국학생의 한국어발음 특징을 음향, 음성학적 방법으로 분석하였다. 방 법: 우리말의 파열음(ㅂ, ㅃ, ㅍ, ㄷ, ㄸ, ㅌ, ㄱ, ㄲ, ㅋ) 9개를 VCV 형식으로 녹음하여 폐쇄구간과 기식구간 길이와 비율을 측정하였다. 해외귀국학생 군과 국내거주학생 간 파열음의 조음오류의 비율과 유형을 비교하고 조음위치와 발성유형에 따른 음향음성학적 특성을 분석, 비교하였다. 결 과: 해외귀국학생 군과 국내거주학생 군 간 조음오류 비율은 해외귀국학생 군 19.4%, 국내거주학생 군 2%로 나타났다. 해외귀국학생군의 발음 오류 중 가장 많이 나타난 유형으로 발성 유형의 오류는 경음화, 조음 위치의 오류는 비음화 이었다. 해외귀국초등학생 군이 국내거주 초등학생군 보다 모든 조음위치와 발성유형에서 파열음의 폐쇄구간, 기식구간 길이가 유의하게 길게 나타났다. 그러나 대상군간 폐쇄구간 대 기식구간의 길이의 비율을 비교한 결과 유의하지 않았다. 결 론: 해외귀국학생은 국내거주학생보다 파열음 산출에 조음 오류가 더 자주 일어나며 국내거주학생보다 각 조음위치에 따른 발성유형을 분류하여 정확한 발음을 찾아 산출하는 우리말 발화속도가 느리다는 것을 알 수 있었다. 해외귀국초등학생 발음의 음향음성학적 문제점을 이해하고 추후 해외귀국초등학생의 조음을 평가하는 객관적인 자료에 도움이 될 것이다.

• 음성과학
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• 제10권2호
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• pp.207-221
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• 2003

Phonetic voicing does not support the phonological distinction of voiced/voiceless in English stops. The present study is aimed at defining the nature of voicing of English voiced stops. A review of the literature reveals that the voicing is position-conditioned and its length is notably inconsistent relative to the closure duration. No consistent relationships are found between vocal fold adduction and glottal pulsing in initial position. Stress reduced the voicing, etc. The hypothesis for experiments was: (1) active voicing: stress generates longer (stronger) voicing during the closure duration of a voiced stop; (2) passive voicing: stress induces shorter (weaker) voicing during the closure. Instead the voiced stop becomes more voiced when the preceding vowel (syllable) is stressed. The literature review and the results of two experiments comparing English and Slovakian suggested that the voicing of English voiced stops is passive (i.e., a coarticulation of glottal pulsing for adjacent vowels-syllables) and should be distinguished from active voicing in some other languages.

• 한국지능시스템학회논문지
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• 제18권2호
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• pp.223-229
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• 2008

본 논문에서는 비젼을 이용한 영상처리 기술을 기반으로 운전자의 피로도를 측정하여 졸음운전을 판단하는 실시간 비젼시스템을 제안한다. 제안된 시스템은 얼굴 영상 분석과 퍼지 이론을 이용하여 운전자의 졸음 또는 부주의함을 경고함으로서 교통사고를 미연에 방지하는 시스템이다. 본 논문에서는 실시간 얼굴 탐색 알고리즘 개발을 위해 퍼지 색상 필터와 가상 얼굴 모형을 이용하여 얼굴 위치 및 눈 영역을 보다 빠르게 검출하고, 눈 깜박임의 빈도수(eye blinking frequency)와 눈의 닫힘 지속 기간(eye closure duration)을 측정하는 방법은 제안한다. 그 다음, 측정된 데이터를 기반으로 퍼지논리를 사용하여 운전자의 피로도를 결정하고 졸음운전 여부를 판단하는 방법을 제안한다. 마지막으로 제안된 방법은 여러 실험을 통해 그 우수성과 응용 가능성을 증명한다.

• 말소리와 음성과학
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• 제14권4호
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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.

• 음성과학
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• 제5권2호
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• pp.17-26
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• 1999

It has been claimed that Korean mid-vocalic voiceless unaspirated lax stops are phonetically realized with voicing throughout the oral closure phase. Acoustic measurements were undertaken to examine the claim with four Korean native speakers using /$V_1CV_2$/ words where the vowel ($V_1\;=\;V_2$) was /i, a, u/ and the C was voiceless unaspirated lax stops /p, t, k/. Findings: (1) During mid-vocalic stops /k/ and /p/ the vowel /u/ was accompanied generally by a significant increase in voice cessation time as percentage of the oral closure interval (PCT) than the vowel /a/, regardless of subjects, whereas in mid-vocalic alveolar stop /t/ the effects of vowels on PCT were subject-dependent, (2) The effects of vowels on PCT were significantly greater in mid-vocalic /k/ than /p/, regardless of subjects, (3) The mean PCT, averaged across six tokens, ranged from 17% to100%, giving overall mean 61% in which the standard deviation was ${\pm}30$, and (4) Overall % of the total of mid-vocalic unaspirated lax stops were produced with a substantial period of devocing and voicing lag. Considering these results, it is difficult to agree with the existing claims that Korean voiceless unaspirated lax stops are phonetically realized with voicing throughout the oral closure phase. Other phonetic variables, including the durations of pre/post-stop vowels, voice onset time, voice cessation time, and the duration of oral closure, were measured.