• 대한후두음성언어의학회지
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• 제17권2호
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• pp.89-97
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• 2006

The stop consonants in Korean are classified into three types according to the manner of articulation as unaspirated (UA), slightly aspirated (SA) and heavily aspirated (HA) stops. Both the UA and the HA types are always voiceless in any environment. Generally, the voice onset time (VOT) could be measured spectrographically from release of consonant burst to onset of following vowel. The VOT of the UA type is within 20 msec of the burst, and about 40-50 msec in the SA and 50-70 msec in the HA. There have been many efforts to clarify properties that differentiate these manner categories. Umeda, et $al^{1)}$ studied that the fundamental frequency at voice onset after both the UA and HA consonants was higher than that for the SA consonants, and the voice onset times were longest in the HA followed by the SA and UA. Han, et $al^{2)}$ reported in their speech synthesis and perception studies that the SA and UA stops differed primarily in terms of a gradual versus a relatively rapid intensity build-up of the following vowel after the stop release. Lee, et $al^{3)}$ measured both the intraoral and subglottal air pressure that the subglottal pressure was higher for the HA stop than for the other two stops. They also compared the dynamic pattern of the subglottal pressure slope for the three categories and found that the HA stop showed the most rapid increase in subglottal pressure in the time period immediately before the stop release. $Kagaya^{4)}$ reported fiberscopic and acoustic studies of the Korean stops. He mentioned that the UA type may be characterized by a completely adducted state of the vocal folds, stiffened vocal folds and the abrupt decreasing of the stiffness near the voice onset, while the HA type may be characterized by an extensively abducted state of the vocal folds and a heightened subglottal pressure. On the other hand, none of these positive gestures are observed for the SA type. Hong, et $al^{5)}$ studied electromyographic activity of the thyroarytenoid and posterior cricoarytenoid (PCA) muscles during stop production. He reported a marked and early activation of the PCA muscle associated with a steep reactivation of the thyroarytenoid muscle before voice onset in the production of the HA consonants. For the production of the UA consonants, little or no activation of the PCA muscle and earliest and most marked reactivation of the thyroarytenoid muscle were characteristic. For the SA consonants, he reported a more moderate activation of the PCA muscle than for the UA consonant, and the least and the latest reactivation of the thyroarytenoid muscle. Hong, et $al^{6)}$ studied the observation of the vibratory movements of vocal fold edges in terms of laryngeal gestures according to the different types of stop consonants. The movements of vocal fold edges were evaluated using high speed digital images. EGG signals and acoustic waveforms were also evaluated and related to the vibratory movements of vocal fold edges during stop production.

• 음성과학
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• 제9권2호
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• pp.25-47
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• 2002

Human language activity in the information society has been developing the communication system between humans and machines. The aim of this study was to analyze dialectal speech in Korea. One hundred Kyungsang and one hundred Cholla informants participated in this study. A CSL and Flexible laryngeal fiberscope were used for analysis of the acoustic and glottal gestures of all the vowels and consonants. Test words were made on the picture cards and letter cards which contained each vowel and each consonant, respectively. The dialogue between the examiner and the informants was recorded in a question and answer manner. The acoustic results of two dialects were as follows: Kyungsang and Cholla informants showed neutralization between /e/ and /$\varepsilon$. However, the apertures of Kyungsang vowels /i, w, u, o/ were higher than those of Cholla vowels. The /wi/ and /$\varepsilon$/ of Kyungsang Diphthong vowels were shown as simple vowels /i/ and /$\varepsilon$/ in Cholla dialect. The VOT of Cholla dilaect was longer than that of Kyungsang dialect. The fricative frequence of Kyurlgsang dialect was about 1000Hz higher than that of Cholla dialect. The glottal widths on fiberscopic images showed that the consonant durations of Kyungsang and Cholla dialects were correlated all together with the acoustic duration on the spectrogram.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1996년도 10월 학술대회지
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• pp.206-206
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• 1996

Previous studies of American English(e.g. Sussman 1991, 1993, 1994) CVC coarticulation with initial consonants representing the labial, alveolar, and velar showed a linear relationship that fits to data points formed by plotting onsets of F2 transition along the y-axis and their corresponding midvowel points along the x-axis. The present study extends the locus equation metric to include the following places of articulation:uvular, pharyngeal, laryngeal, and emphatics. The question of interest is to determine if locus equation could serve as phonetic descriptor for the place of articulation in Arabic. Five male native speakers of Colloquial Egyptian Arabic(CEA) read a list of 204 CVC and CVCC words, containing eight different places of articulation and eight vowels. Average of formant patterns(Fl,F2,F3) onsets, midpoints, and offsets were calculated, using wide band spectrograms obtained by means of the kay spectrograph model(7029), and plotted as locus equations. A summary of the acoustic properties of the place of articulation of CEA will be presented in the frames of bVC and CVb. Strong linear regression relationships were found for every place of articulation.

• 음성과학
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• 제10권3호
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• pp.89-101
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• 2003

This paper investigates edge effects on the relationship between the underlying tonal sequence and its surface realization in the IP-final Accentual Phrase within the Optimality Theoretic framework. I will examine the way in which AP tones are aligned with their associated syllables in IP-final position. In Korean. Jun's (1996) 'see-saw effect' does not allow any two identical tones if they are marking a boundary of a prosodic group. A phonetic experiment conducted in this paper suggests that the 'see-saw effect' only apply to H boundary tones. Furthermore, it will be shown that the timing of tonal peaks is determined through the ranking of a set of violable constraints. The AP tonal realization is achieved through the access to the global intonation in a complicated way. In the course of discussion, pitch patterns in IP-medial Accentual Phrase will also be discussed.

• 음성과학
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• 제10권1호
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• pp.3-13
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• 2003

The devoicing vowel is a phonological process whose contrast in sonority is lost or reduces in a particular phonetic environment. Phonetically, the vocal fold vibration originates from the abduction/adduction of the glottis in relation to supraglottal articulatory movements. The purpose of this study is to investigate Korean vowel devoicing by means of experimental instruments. The interrelated laryngeal adjustments and aerodynamic effects for this voicing can clarify the redundant articulatory gestures relevant to the distinctive feature of sonority. Five test words were selected, being composed of the high vowel /i/, between the fricative and strong aspirated or lenis affricated consonants. The subjects uttered the test words successively at a normal or at a faster speed. The EMG, the sensing tube Gaeltec S7b and the High-Speech Analysis system and MSL II were used in these studies. Acoustically, three different types of speech waveforms and spectrograms were classified, based on the voicing variation. The intraoral air pressure curves showed differences, depending on the voicing variations. The activity patterns of the PCA and the CT for devoicing vowels appeared differently from those showing the partially devoicing vowels and the voicing vowels.

• 음성과학
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• 제9권1호
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• pp.17-26
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• 2002

Voice onset time (VOT) is defined as the time interval from the oral release of a stop consonant to the onset of glottal pulsing in the following vowel. VOT is a temporal characteristic of stop consonants that reflects the complex timing of glottal articulation relative to supraglottal articulation. There have been many reports on efforts to clarify the acoustical and physiological properties that differentiate the three types of Korean stops, including acoustic, fiberscopic, aerodynamic and electromyographic studies. In the acoustic and fiberscopic studies for stop consonants, the voice onset time and glottal width during the production of stops has been known as the longest and largest in the heavily aspirated type followed by the slightly aspirated type and unaspirated types. The thyroarytenoid and posterior cricoarytenoid muscles were physiologically inter-correlated for differentiating these types of stops. However, a review of the English literature shows that the fine movement of the mucosal edges of the vocal folds during the production of stops has not been well documented. In recent. years, a new method for high-speed recording of laryngeal dynamics by use of a digital recording system allows us to observe with fine time resolution. The movements of the vocal fold edges were documented during the period of stop production using a fiberscopic system of high speed digital images. By observing the glottal width and the visual vibratory movements of the vocal folds before voice onset, the heavily aspirated stop was characterized as being more prominent and dynamic than the slightly aspirated and unaspirated stops.

• 말소리와 음성과학
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• 제4권2호
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• pp.61-70
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• 2012

The current study observes the durational interaction of tautosyllabic consonants and vowels in the word-initial position of English and Korean child-directed speech (CDS). The effect of phonological laryngeal contrasts in stops on the following vowel duration, and the effect of the intrinsic vowel duration on the release duration of preceding stops in addition to the acoustic realization of the contrastive segments are explored in different prosodic contexts - phrase-initial/medial, focal accented/non-focused - in a marked speech style of CDS. A trade-off relationship between Voice Onset Time (VOT), as consonant release duration, and voicing phonation time, as vowel duration, reported from adult-to-adult speech, and patterns of durational variability are investigated in CDS of two languages with different linguistic rhythms, under systematically controlled prosodic contexts. Speech data were collected from four native English mothers and four native Korean mothers who were talking to their one-word staged infants. In addition to the acoustic measurements, the transformed delta measure is employed as a variability index of individual tokens. Results confirm the durational correlation between prevocalic consonants and following vowels. The interaction is revealed in a compensatory pattern such as longer VOTs followed by shorter vowel durations in both languages. An asymmetry is found in CV interaction in that the effect of consonant on vowel duration is greater than the VOT differences induced by the vowel. Prosodic effects are found such that the acoustic difference is enhanced between the contrastive segments under focal accent, supporting the paradigmatic strengthening effect. Positional variation, however, does not show any systematic effects on the variations of the measured acoustic quantities. Overall vowel duration and syllable duration are longer in English tokens but involve less variability across the prosodic variations. The constancy of syllable duration, therefore, is not found to be more strongly sustained in Korean CDS. The stylistic variation is discussed in relation to the listener under linguistic development in CDS.

• 음성과학
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• 제11권2호
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• pp.71-87
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• 2004

Korean has a pair of voiceless fricatives, whose laryngeal manifestation comes in parallel to stops and affricates with a three-way lexical contrast. Prior phonetic studies by Kagaya (1974), Iverson (1983), and Kang (1999, 2000) point out /s/ is associated with multiple characteristics of the larynx shared with not only the lax but also the aspirated series, whereas /s' / carries a laryngeal distinction typical of the tense consonants. The complex dual nature of /s/ is again supported by a psycholinguistic study by Kang (2004), as /s/ was found to interact with /$c^h$/ (17% of the time) as well as /c/ (57%) in speech errors. In addition, a recent work by Cho and Lee (2003) notes an interesting chain shift case in the acquisition of the fricatives. Although they observed a significant phonological pattern between child English and Korean, Cho and Lee's description of acquiring fricatives is far from being precise from the perspective of phonetics. From a longitudinal study of recorded tapes by two children at 1;7-3;8 and 1;7-2;1 respectively, I found that /s' / was usually substituted into tense noncontinuants in young children's early production as predicted, whereas /s/ having both lax and aspirated-like glottal properties revealed a complicated pattern of substitutions into lax, tense, and aspirated noncontinuants with a varying degree of preference relative to the subjects. The current acquisition study supports the previous claims concerning fricatives in other languages, showing that their acquisition comes after stops. Besides, it also notes that Korean fricatives are subject to a series of phonological processes called stopping, affricating, tensifying and palatalizing during the transitional period of phonological development by young children. Moreover, between the two voiceless types, /s/ was acquired earlier than /s'/ as the unmarked segment.

• 말소리와 음성과학
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• 제2권1호
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• pp.41-50
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• 2010

The current study exploresacoustic variation induced by prosodic contexts in different speech styles,with a focus on motherese or child-directed speech (CDS). The patterns of variation in the acoustic expression of voicing contrast in English stops, and the role of prosodic factors in governing such variation are investigated in CDS. Prosody-induced acoustic strengthening reported from adult-directed speech (ADS)is examined in the speech data directed to infants at the one-word stage. The target consonants are collected from Utterance-initial and -medial positions, with or without focal accent. Overall, CDS shows that the prosodic prominence of constituents under focal accent conditions variesin the acoustic correlates of the stop laryngeal contrasts. The initial position is not found with enhanced acoustic values in the current study, which is similar to the finding from ADS (Choi, 2006 Cole et al, 2007). Individualized statistical results, however, indicate that the effect of accent on acoustic measures is not very robust, compared to the effect of accent in ADS. Enhanced distinctiveness under focal accent is observed from the limited subjects' acoustic measures in CDS. The results indicate dissimilar strategies to mark prosodic structures in different speech styles as well as the consistent prosodic effect across speech styles. The stylistic variation is discussed in relation to the listener under linguistic development in CDS.

• 말소리와 음성과학
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• 제11권4호
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• pp.63-70
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• 2019

This study investigated individual variability of L2 learners' categorical judgments of L2 stops by exploring English learners' perceptual processing of two acoustic cues (voice onset time [VOT] and f0) and working memory capacity as sources of variation. As prior research has reported that English speakers' greater use of the redundant cue f0 was responsible for gradient processing of native stops, we examined whether the same processing characteristics would be observed in L2 learners' perception of Korean stops (/t/-/t^h/). 22 English learners of L2 Korean with a range of L2 proficiency participated in a visual analogue scaling task and demonstrated variable manners of judging the L2 Korean stops: Some were more gradient than others in performing the task. Correlation analysis revealed that L2 learners' categorical responses were modestly related to individuals' utilizations of a primary cue for the stop contrast (VOT for L1 English stops and f0 for L2 Korean stops), and were also related to better working memory capacity. Together, the current experimental evidence demonstrates adult L2 learners' top-down processing of stop consonants where linguistic and cognitive resources are devoted to a process of determining abstract phonemic identity.