• 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.

• Speech Sciences
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• v.5 no.2
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• pp.139-159
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• 1999

The purposes of this study are two-folds: to find out the acoustic features of Korean stops in various utterance positions and their influence on the neighbouring segments. Korean stops($/p,\;p',\;p^{h};\;t,\;t',\;t^{h};\;k,\;k',\;k^{h}/$) are examined from CV, $V_1CV_2,\;V_1NCV_2,\;V_1LCV_2$ sequences. Three speakers (two male and one female speakers of Seoul dialect) served as subjects for the present study. VOT, closure duration of the target stops and duration of the neighbouring segments were measured from acoustic data. The results can be summarized as follows. First, stops show different temporal aspects depending on their place of articulation as well as their voice types. Velar stops tend to have shorter closure duration and longer VOT due to relatively slower movement of the articulator (i.e. tongue body) and higher supraglottal air pressure during the closure, respectively. Second, temporal aspects of the neighbouring segments appear to be influenced by the voice type of stop. The preceding segment tends to be longer when a stop has shorter duration. On the other hand, the following segment tends to be shorter, when a stop has longer VOT.

• MALSORI
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• no.45
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• pp.23-33
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• 2003

This is a study on perception errors of Korean stops in word initial position. This study will show how listeners perceive manipulated Korean stops through two experiments and I will analyze why they are confused. In addition, 1 will show those perception errors not only reflect the relationship between the place and manner of articulation but also ate deeply related to the length of aspiration.

• Proceedings of the KSPS conference
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• 2004.05a
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• pp.139-142
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• 2004

This study examines the acoustic characteristics of Korean stops of two dialect, Seoul and Daegu, 20 speakers of these two dialects were asked to read 15 words containing the stops of different places of articulation and phonation types at initial. The stops in the two dialects show mainly two acoustic differences. Firstly, There was a difference in distinctive features for phonetic types in the two dialects. Secondly, lenis revel fortis`s characters in Daegu dialect.

• 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.

• MALSORI
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• no.46
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• pp.1-11
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• 2003

This study examines the acoustic characteristics of Korean stops of two dialects, Seoul and Kyungsang, focusing on VOT(Voice Onset Time). 8 speakers of these two dialects were asked to read 590 words which contain the stops of different places of articulation and phonation types. The results showed that overall the VOTs of Kyungsang dialect were shorter than those of Seoul dialect. This was more prominent in lenis stops than in fortis or aspirated stops. It was also shown that there were significant VOT overlapping differences between the two dialects.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.31-41
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• 2012

Recent studies have shown that the stop system of Korean is undergoing a sound change in terms of the two acoustic parameters, voice onset time (VOT) and fundamental frequency (f0). Because of a VOT merger of a consonantal opposition and onset-f0 interaction, the relative importance of the two parameters has been changing in Korean where f0 is a primary cue and VOT is a secondary cue in distinguishing lax from aspirated stops in speech production as well as perception. In English, however, VOT is a primary cue and f0 is a secondary cue in contrasting voiced and voiceless stops. This study examines how Korean English learners use the two acoustic parameters of L1 in producing L2 English stops and whether the sound change of acoustic parameters in L1 affects L2 speech production. The data were collected from six adult Korean English learners. Results show that Korean English learners use not only VOT but also f0 to contrast L2 voiced and voiceless stops. However, unlike VOT variations among speakers, the magnitude effect of onset consonants on f0 in L2 English was steady and robust, indicating that f0 also plays an important role in contrasting the [voice] contrast in L2 English. The results suggest that the important role of f0 in contrasting lax and aspirated stops in L1 Korean is transferred to the contrast of voiced and voiceless stops in L2 English. The results imply that, for Korean English learners, f0 rather than VOT will play an important perceptual cue in contrasting voiced and voiceless stops in L2 English.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4D
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• pp.527-538
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• 2011

Currently, the only established criteria is on the location of bus stops on principal roads where uninterrupted flow mainly occurs. There are no clear guidelines on any method to locating bus stops considering the characteristics of bus operation and pedestrians. If the location or exterior of a bus stop is inappropriate, road users including bus drivers and pedestrians will be caused serious dangerous and inconvenience. In this study, the research below was performed in order to propose rational criteria for the location of bus stops integrated with or separated from speed-change lanes at signalized intersections considering smooth traffic flow and the characteristics of bus operation and pedestrians as well as traffic safety : First, the appropriate length of each of the near-side and far-side bus stops was calculated by categorizing bus stops to be constructed into those integrated with speed-change lanes and those separated from speed-change lanes. Secondly, the appropriate length of each of the bus stops divided into near-side bus stops and far-side bus stops and integrated with or separated from speed-change lanes was selected by considering the characteristics of pedestrians. Thirdly, whether the construction locations of bus stops were appropriate or not was determined based on the appropriate length of bus stops integrated with or separated from speed-change lanes, which was calculated and selected by considering traffic flow and the characteristics of pedestrians and considering traffic safety. The method for locating bus stops considering traffic flow, the characteristics of pedestrians, and traffic safety will be able to help suggestion criteria of bus stop and the location of safe and pleasant bus stops.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.185-193
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• 2013

This study investigates dialectal differences in the acoustic properties of Korean lenis, aspirated, and tense stops Seoul Korean (standard Korean) and Yanbian Korean (spoken in the largest Korean Autonomous Prefecture in China). This production study the main acoustic cues that each dialect uses to mark the laryngeal distinction between the three types of Korean stops. Measurements included VOT, and the initial F0 of the following vowel. Data collected from 10 young Seoul Korean speakers, 10 young Yanbian Korean speakers, and 6 older Yanbian speakers. two key findings: First, aspirated and lenis stops are mainly differentiated by F0 in Seoul Korean, and by $H1^*-H2^*$ in Yanbian Korean. Second, there is no VOT merger between lenis and aspirated stops in Yanbian Korean, whereas there is in Seoul Korean. These results are discussed in terms of the phenomenon of VOT shift and the function of F0t is argued that the function of F0 to substitute for VOT difference as a primary cue for the coding of laryngeal contrast can be predicted by the pitch accent system of the language involved.

• Speech Sciences
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• v.3
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• pp.109-117
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• 1998

This paper tests whether the VOT (Voice Onset Time) contributes to the perception of tense and plain stops in Korean in the initial position. Previous studies have yielded opposite results regarding the role of the VOT in the distinction of these two stop categories. One the one hand, Lisker and Abramson (1964), Kim (1965), and Han and Weitzman (1970) suggest that the Korean plain and tense stops exhibit overlapping values of VOT and thus that, unlike many other languages, the VOT fails to serve as a cue to separate these stop categories. On the other hand, Silva (1991, 1992), and Lee (1991, 1994) use similar methods, but find that the VOT serve as the cue. In this study, the differences in the acoustic measurement with respect to the VOT of Korean plain and tense stops in initial prevocalic position will be tested preceptually, in seeking to determine whether these acoustic differences are used by listeners to distinguish these two stop types.