• 말소리와 음성과학
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• 제4권3호
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• pp.85-92
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• 2012

It is a well-known phenomenon that vowel duration in English is generally longer before a voiced stop than a voiceless one. Past research has postulated that the closure duration of the voiceless stop is generally longer than that of the voiced stop and that the duration of a preceding vowel is determined complementarily by the closure duration of the stop. To shed further light on the phenomenon, this study examined fourteen native speakers of American English who read the monosyllabic words [bVC] (V = [i, ɪ, eɪ, ɛ, æ, ʌ, ɑ], C = [t, d]). First, we found that mean vowel duration was 38 ms longer before the voiced stop than the voiceless (mean duration ratio = 1.24). Second, mean closure duration of the voiced stop was only shorter by 5 ms compared to the voiceless stop (mean duration ratio = 0.97). Therefore, for our subjects, vowel duration was not determined complementarily by the closure duration of the following stop. Third, vowels with longer inherent durations (viz., tense, diphthong, and low vowels) tended to show larger duration ratios in the voiced and voiceless contexts than the vowels with shorter durations (viz., lax vowels). This indicates that the lengthening of inherently shorter vowels before a voiced stop is limited in order to avoid overlapping with longer vowels in the duration range. Fourth, there was no significant gender difference in vowel duration ratios in the contexts of voiced and voiceless stops. Finally, considerable individual differences were found in the vowel and consonant duration ratios.

• 음성과학
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• 제9권4호
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• pp.201-214
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• 2002

In the Japanese language, there is a phonological contrast between not only initial stops, but also non initial in voiced and voiceless sounds. But in the Korean language, voiced sounds do not appear in the initial. Due to this, pronunciation of voiced sounds in the initial will be difficult for Korean. Through this research, I analyzed the minimal pairs by voiced/voiceless sounds of Japanese and Korean, and perception experiment in which Japanese listened to Korean speakers' pronunciations. Japanese pronunciations showed distinct acoustic differences between voiced and voiceless stops, especially in VOT. The duration of vowels after voiced stops was longer than that of voiceless ones. Vowel pitches after voiceless stops were higher. On the other hands, Korean showed three patterns of voiced sounds. There were-VOT values as native speakers, +VOT, and nasal formant tended to occur before prenasalized stops. Koreans pronounced voiceless sounds in strong aspirated, unaspirated, or tense sounds. Finally, Japanese judged sounds with not only -VOT values and prenasalized, but also with +VOT values as voiced. This suggests that we may not consider VOT values as the unique feature of voicing, and that such other phonetic characteristics as the following vowel lengthening should be included here.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2000년도 7월 학술대회지
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• pp.199-199
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• 2000

Korean stops are 3 system: aspirated, fortis, lenis, whereas English stops are 2 system: voiced, voiceless. Because in Korean, lenis stop is realized by slight aspirated voiceless stop, it is likely to produce English word initial voiced stop as voiceless stop. We divide subjects into three group-native, experienced, unexperienced- and investigate differences between group. VOT of experienced group IS same as native group, but VOT of unexperienced group is longer than native group. VOt of unexperienced group is 1.8 times than native group. We survey whether the height of following vowel influences VOT of initial stop. As a result, for all group, VOT followed by low vowel is shorter than VOT followed by high vowel. But this tendency is more salient in unexperienced group. For high vowel, VOT of unexperienced group is 2.05 times than native group, whereas for low vowel, it is just 1.55 times. The unexperienced pronounce well English word initial voiced stop followed by low vowel than high vowel. Samples are divided into two group according to type of coda consonant- nasal and voiceless stop. But average of VOT is similar and there is no significant difference between two groups. There is no influence by type of coda consonant. The average of phrases is compared to the average of isolated words. In the case of natives and experienced, there is no significant differences between phrases and words, but in the case of unexperienced, VOT of phrases becomes shorter than words. But VOT of unexperienced is still longer than native group.

• 한국어학
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• 제79권
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• pp.63-89
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• 2018

This study explores contrastive relation among voiced bilabial fricative [${\ss}$], voiceless bilabial stop [p] and glide [w] in Middle Korean consonant system based on Probabilistic Model. Preceding researches about voiced bilabial fricative [${\ss}$] proposed two influential arguments. One is voiced bilabial fricative [${\ss}$] was an independent phoneme, the other is it was not an independent phoneme but an allophone of voiceless bilabial stop [p] in Middle Korean. This study applies Probabilistic Phonological Relationship Model (PPRM) for solving the problem of dichotomy about contrastive and allophonic relations. The analysis result of the contrastive entropy by PPRM suggests that voiced bilabial fricative [${\ss}$] was just an allophone of voiceless bilabial stop [p] or glide [w] in Middle Korean. Comparing the entropies between [p] and other consonants with the entropies between [${\ss}$] and other consonants, a continuum defined in terms of entropy reveals that [${\ss}$] in Middle Korean was more allophonic than phonemic.

• 한국영어학회지:영어학
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• 제2권1호
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• pp.23-30
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• 2002

Phonologically, the difference between the English stops /b, d, g/ and /p, t, k/ is carried by the presence or the absence of the vocal fold vibration throughout their oral closure phase. If phonology has its foundation in phonetics, there must be phonetic evidence for the voiced-voiceless distinction. This study is aimed to determine whether or not the voiced-voiceless distinction is acceptable or proper in English. The determination was based mainly on findings in the existing literature and in informal experiments. In conclusion, there is no phonetic evidence for the voiced-voiceless distinction both in production and perception. The [voice] appears to be one of potential phonetic correlates of the phonologically voiced stop. It is improper to use the [voice] as independent phonological marker, regardless of position (word-initial, intervocalic, word-final). A feature other than the voiced-voiceless feature must distinguish /b, d, g/ from /p, t, k/.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2000년도 7월 학술대회지
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• pp.165-165
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• 2000

In the phoneme level, English stop sounds are classified with the feature of 'voicing': voiceless and voiced (p/b, t/d, k/g). But when realized, a voiceless stop is not alwats the same sound. For example, the two 'p' sounds in 'people' are different. The former is pronounced with much aspiration, while the latter without it. This allophonic differnece between [$P^h$] and [p] out of an English phoneme /p/ can be well explained to Koreans because in Korean these two sounds exist as two different phonemes {/ㅍ/ and /ㅃ/ respectively). But difficulties lie in teaching the English voiced stop sounds (/b, d, g/) to Koreans because in Korean voiced stops do not exist as phonemes but as allophones of lenis sounds (/ㅂ, ㄷ, ㄱ/). For example, the narrow transcription of '바보' (a fool) is [baboo]. In the word initial position, Korean lenis stops are pronounced voiceless and even with a slight aspiration while in the inrervocalic environments they become voiced, That is in Korean voiced stops do not occur independently and neither they have their own letters. To explain all these more effectively to Koreans, it is very helpful to use Korean Phenetic Alphabet (KPA) which is devised by Dr. LEE Hyunbok (a professor of phonetics at Seoul National Univ. and chairman of Phonetic Society of Koera.)(omitted)

• 한국영어학회지:영어학
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• 제3권3호
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• pp.427-452
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• 2003

Korean is famous for having all voiceless stop sounds. Korean does have voiced stops but they are considered to exist only as the allophones of word initial /p, t, k/. My experiment shows the English word initial stop sounds [b, d, g] and the Korean lax stop series /p, t, k/ in word initial position are similar in the range of voice onset time. If English word initial[b, d, g] sounds are posited as voiced, then Korean word initial /p, t, k/ should be classified as voiced also. Phonetically English /b, d, g/ phonemes and Korean /p, t, k/ phonemes are very similar except the word initial [p, t, k] are devoiced slightly more, but not significant enough to be classified as voiceless than English word initial [b, d, g]. If we posit /b, d, g/ as Korean phonemes, it explains why Korean /p, t, k/ series has the allophones [b, d, g] instead of fortis stops /p', t', k'/ in Korean even though /p', t', k'/ has less positive VOT value than /p, t, k/. If we posit /b, d, g/ as Korean phonemes, then it does not cause spelling or pronunciation confusion either when Koreans learn English or English speakers learn Korean.

• 음성과학
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• 제9권4호
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• pp.175-185
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• 2002

The purpose of this study was to investigate the acoustic durations of Korean vowels followed by either voiced or voiceless consonants. Six healthy adult speakers (2 females and 4 males) recorded nonsense syllables in which voiced (/b, d, g/) or voiceless (/p', t', k', $p^{h},t^{h},k^{h}$) consonants follow three different vowels (/i, a, u/) embedded in a carrier phrase. Results showed that vowels preceding voiced consonants (e.g., haba) were significantly longer in duration than those preceding voiceless consonants (e.g., hiP' a or $hip^{h}a$). Also vowels were longer in duration when occurring before velar-stops than before bilabial-stop and dental-stops. Finally, the duration of the low vowel (/a/) was substantially longer than that of the high vowels (/i, u/). These findings may be applicable to speech synthesis or therapy.

• 말소리와 음성과학
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• 제3권1호
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• pp.15-22
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• 2011

The purposes of this study are (1) to investigate the correlation between English word-final stop and the duration of vowels before word-final stop and (2) to suggest a way to detect pronunciation errors and teach the pronunciation of English word-final stops. For these purposes, 18 Korean speakers' production was recorded and analysed using Speech Analyzer and their production was compared with that of native English speakers. In addition, two native English speakers evaluated the subjects' pronunciation. The major findings are the voicing dependent effect of the English vowels produced by native Korean speakers is lower than that of native English speakers; Korean speakers release English word-final stops less than native English speakers; and the pronunciation of English word-final stops and the duration of adjacent vowels are closely related in that the pronunciation score of final stops and the ratio of vowels between the vowels before voiced stops and voiceless stops are correlated. In addition, this study concludes with pedagogical suggestions that may be useful for English pronunciation teaching.

• 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.