• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.2
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• pp.152-157
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• 2005

Background and Objectives : 10 normal Korean native speakers participated subjects to investigate the acoustic and aerodynamic study of Korean fricatives, affricates, and plosives and to make good use of the results for the patients with articulation problems. Materials and Method Their productions of [asa], [as'a], [aca], $[ac^ha]$, (ac'a), (ata) , $[at^ha]$, and [at'a] were analyzed with Lx Speech Studio Program (Laryngogrtaph Ltd, UK) for acoustic analysis and Phonatory Function Analyze. (Nagashima Ltd. Model PS 77H, Tokyo, Japan) for aerodynamic analysis. Results : The results are as follows : 1) Plosives showed higher Qx1 in vocal folds closure ratio than fricatives and affricates. 2) Tense fricatives, affricates, and plosives showed higher Qx2 in vocal folds closure ratio than asperated and 1ax. 3) Asperated showed higher Qx1 in vocal folds closure ratio than tense and 1ax. 4) Asperated showed higer peak flow rate than tense and 1ax. Conclusion This results may be helpful for treatment in articulation disorders.

• Speech Sciences
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• v.12 no.1
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• pp.89-105
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• 2005

This paper is a production study of the effects of Korean prosody on two voiceless coronal fricatives /$s^h$/ and /s*/. The target segments were embedded in four prosodic positions: initial to the Intonational Phrase or the Accentual Phrase, and medial to the Accentual Phrase or to the Prosodic Word. Acoustic measurements showed that the durational differences associated with the /$s^h$/ versus /s*/ contrast vary in magnitude in different prosodic positions, confirming the proposal that segmental properties are affected by prosodic categories. This suggests that any speech synthesizer should take into consideration prosodically conditioned durational variation.

• 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.

• MALSORI
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• no.49
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• pp.31-50
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• 2004

This study investigates spectral characteristics of frication noise in Korean sibilants in terms of center of gravity and skewness. Specifically, the present study seeks to observe the two parameters with emphasis on place of articulation in different vowel environments. This study also examines whether these parameters can discriminate phonation types. The results showed that the fricatives are palatalized in front of the front vowel /i/ and the affricates are articulated at the same place of articulation regardless of the following vowels. This study also suggests that the place of articulation of the fricatives followed by /i/ is the same as those of the Korean affricates. With regard to the phonation type, there was a significant difference in the center of gravity between lax and tense series for both fricatives and affricates.

• Speech Sciences
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• v.4 no.1
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• pp.135-145
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• 1998

An Electropalatographic (EPG) study was conducted to investigate the articulatory characteristics which determine the, distinction between the Korean lax fricative [s] and tense fricative [s']. This study also intended to test if an increase in the degree of tensity (lax fricative [s] < tense fricative [s']) induces a decrease in coarticulatory vocalic effects. The results indicated that the increase in the tensity of Korean fricatives is closely related to the increase in the narrowness of the groove width (wider contact at the place of articulation), the forward shifting in the place of articulation, and the longer duration of the constriction (longer maintenance in the manner of articulation). It was also found that coarticulatory vocalic effects on Korean fricatives are affected by Recasens' two rules of constraint (1983) : spatial and temporal constraints.

• Speech Sciences
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• v.10 no.1
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• pp.59-67
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• 2003

The purpose of this study was to investigate Korean native speakers' perception of English sounds according to groupings of phonetic contrasts. The four groupings looked at were vowels, voicing (voiced-unvoiced), fricatives with difference in place of articulation, and other clusters of specific sound contrasts, such as stop-fricatives and liquids. The position of a sound in syllable was also examined. According to the results of ANOVA and a post-hoc analysis, the perception of vowels, in the medial position was different from that of consonants in the initial and final position. Vowels proved to be the most difficult group to perceive correctly. With the consonants, there was not a big difference whether the contrasts came initially or finally. The order of difficulty was liquids, fricatives, stop-fricatives, and finally voicing.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.93-100
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• 2010

The purpose of this study was to compare the acoustic properties of fricatives, /ㅅ, ㅆ/ produced by children with functional articulation disorder and normal children (N=20, aged 6-7). All subjects showed significant differences in both the length of friction intervals and breathing intervals of fricatives according to the changes in the environment presented within each group. However, there is a difference in the extent of variation in length between the two groups. This means that children with functional articulation disorder have greater difficulty in adjusting fricative noises according to changes in the CV VCV environment than normal children.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.3-12
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• 2012

The primary goal of the current study was to examine category solidity of Korean alveolar fricatives in the Busan and Seoul dialects of Korean. Considering the common belief of $/s^h/-/s^*/$ neutralization in Kyungsang speech, plain $/s^h/$ and fortis $/s^*/$ fricatives of Busan speakers were examined against the same fricatives of Seoul speakers. Perceptual distance between Korean $/s^h/$ and $/s^*/$ on the one hand and English /s/ on the other was investigated by use of across-linguistic mapping method. Two experiments of a perceptual mapping task of English /s/ to Korean $/s^h/$ and $/s^*/$ and a $/s^*/$-production task were conducted on users of the Busan and Seoul dialects of Korean. The results from the perception and production experiments suggested that at a micro-level, younger Busan speakers have less solid category stability for Korean $/s^*/$ compared with Seoul speakers, although their production of $/s^h/$ and $/s^*/$ was as highly distinctive from each other as that of Seoul speakers.

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.117-128
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• 2015

This paper investigates the acoustic-perceptual relation between Korean dent-alveolar fricatives and the English voiceless alveolar fricative /s/ in varied prosodic contexts (e.g., stress, accent, and word initial position). The denti-alveolar fricatives in Korean show a two-way distinction, which can be referred to as either plain (lenis) /s/ or fortis /$s^*$/. The English alveolar voiceless fricative /s/ that corresponds to the two Korean fricatives would be placed in a one-to-two non-native phoneme mapping situation when Korean listeners hear English /s/. This raises an interesting question of how the single fricative of English perceptually maps into the two-way distinction in Korean. This paper reports the acoustic-perceptual mapping pattern by investigating spectral properties of the English stimuli that are heard as either /s/ or /$s^*$/ by Korean listeners, in order to answer the two questions: first, how prosody influences fricatives acoustically, and second, how the resultant properties drive non-native listeners to interpret them as segmental features instead of as prosodic information. The results indicate that Korean listeners' responses change depending on the prosodic context in which the stimuli are placed. It implies that Korean speakers interpret some of the information provided by prosody as segmental one, and that the listeners take advantage of the information in their judgment of non-native phonemes.

• Phonetics and Speech Sciences
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• v.1 no.2
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• pp.105-110
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• 2009

This paper introduces the technique of semi-automatically identifying different types of noise in the frequency domain. Given the lower cutoff frequency of the frication noise, and a user-specified constant, the technique identifies the boundary between the frication and aspiration noise in a Korean lax fricative followed by the vowel /a/ by comparing the upper and lower sums of energy with respect to the cutoff frequency. The user-specified constant can be adjusted for different speakers. When the technique was applied to distinguish the two types of noise of Korean lax fricatives from the same speaker, the average and standard deviation of the difference between the manually inserted boundaries and the automatically inserted boundaries were 2.67ms and 1.80ms respectively.