• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.117-122
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• 2009

A variety of cross-linguistic studies has documented that the acoustic properties of speech addressed to young children include exaggeration of pitch contours and acoustically salient features of phonetic units. It has been suggested that phonetic modifications of child-directed speech facilitate young children's learning of speech sounds by providing detailed phonetic information about the target word. While there are several studies reporting vowel modifications in speech to infants (i.e., hyper-articulated vowels), there has been little research about consonant modifications in speech to young children (except for VOT). The present study examines acoustic properties of Korean stops in Korean mothers' speech to their children (seven children aged 27 to 38 months). Korean tense, lax, and aspirated stops are all voiceless in word-initial position, and are perceptually differentiated by several acoustic parameters including VOT, $f_0$ of the following vowel, and the amplitude difference of the first and second harmonics at the voice onset of the following vowel. This study compares values of these parameters in Korean child-directed speech to those in adult-directed speech from same speakers. Conclusions focus on the acoustic properties of Korean stops in child-directed speech and how they are modified to help Korean young children learn the three-way phonetic contrast.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.11-20
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• 2013

The purpose of this study is to compare the acoustic parameters of English stop consonants at the initial and after-initial-/s/ positions in a message produced by 47 Korean and American speakers in order to provide better pronunciation skills of English stops for Korean learners. A Praat script was developed to obtain voice onset time (VOT), maximum consonant intensity (maxCi), and rate of rise (ROR) from six target words with stops at the positions in the message. Results show that VOT and maxCi were significantly different between the two language groups while ROR wasn't. The Korean speakers generally produced the stop consonants with longer VOTs and higher consonant intensity. From the comparison of consonant groups at the two different positions, the Korean participants did not distinguish them as clearly as the American participants did at the after-initial-/s/ position. Finally a comparison of each language and sex group revealed that the major difference was attributed to stop consonants in the after-/s/ position. The author concluded that Korean speakers should be careful not to produce all the stops with longer VOTs and higher intensity. Further studies would be desirable to examine how Americans evaluate Korean speakers' English proficiency with modified acoustic values of English stops.

• Phonetics and Speech Sciences
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• v.11 no.3
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• pp.1-7
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• 2019

Korean (L1)-English (L2) bilingual adults' and children's production of Korean and English stops was examined to determine the age effects and L2 experience on the development of L1 and L2 stop contrasts. Four groups of Seoul Korean speakers (experienced and inexperienced adult and child groups) and two groups of age-matched native English speakers participated. The overall results of voice onset time (VOT) and fundamental frequency (F0) of phrase-initial stops in Korean and word-intial stops in English showed a delay in the acquisition of L1 due to the dominant exposure to L2. Significantly longer VOT and lower F0 for aspirated stops as well as high temporal variability across repetitions of lenis stops were interpreted to indicate a strong effect of English on Korean stop contrasts for bilingual children. That is, the heavy use of VOT for Korean stop contrasts shows bilingual children's attention to the acoustic cue that are primarily employed in the dominant L2. Furthermore, inexperienced children, but not adults, were shown to create new L2 categories that are distinctive from the L1 within 6 months of L2 experience, suggesting greater independence between the two phonological systems. The implications of bilinguals' age at the time of testing to the degree and direction of L1-L2 interaction are further discussed.

• Phonetics and Speech Sciences
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• v.10 no.4
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• pp.11-17
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• 2018

This study reports on a production experiment designed to investigate how Korean speaking learners of English produce English forms ending in stops. In a repetition experiment, Korean participants listened to English nonce words ending in a stop and repeated what they heard. English speakers were recruited for the same task as a control group. The experimental result indicated that the transcriptions of the Korean productions by English native speakers showed vowel insertion in only 3% of productions although the pronunciation of English final stops showed that noise intervals after the closure of final stops were significantly longer for Korean speakers than for English speakers. This finding is inconsistent with the loanword data where 49% of words showed vowel insertion. It is also not compatible with the perceptual similarity approach, which predicts that because Korean speakers accurately perceive an English final stop as a final consonant, they will insert a vowel to make the English sound more similar to the Korean sound.

• Speech Sciences
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• v.8 no.1
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• pp.93-111
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• 2001

This study investigates the contribution of vocalic information following the release of an initial stop to the identification of the three-way stop contrast (aspirated, lax, and tense) in Korean. Recent studies showed that there is a strong interaction between consonant types and tone. The findings raise questions concerning Korean listeners' use of tonal (or vocalic F0) variation in differentiation initial tense, lax, and aspirated stops. The above issues are addressed in the present study using a cross-splicing methodology. The overall results show that low vocalic F0 provided the most salient information for lax stops; tense and aspirated stop identification depended on a combination of VOT, F0, and H1-H2 characteristics. The perceptual dominance of F0 over VOT for lax stops is consistent with the size of the F0 difference in utterance-initial position, as well as their prominent role in Korean intonational phonology.

• MALSORI
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• no.37
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• pp.13-21
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• 1999

This study, as a successive study of Ko(1998a) which investigates the effect of vowel length contrast on the voicing of the word-final consonants in English, examines if other phonetic features of word-final stops themselves affect the Perception of their voicing. They are closure duration, voicing status during closure period, release portion. 68 Korean students learning English as a second language in Wonkwang University participate as subjects for this study. The results showed that they are not important clues to Korean students to the voicing identification of the word-final stops in English.

• 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.

• Proceedings of the KSPS conference
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• 2005.04a
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• pp.25-28
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• 2005

The purpose of this paper is to represent values of acoustic cues for Korean oral stops in the multi-dimensional space, and to attempt to find possible relationships among acoustic cues through correlation coefficient analyses. The acoustic cues used for differentiation of 3 types of Korean stops are closure duration, voice onset time and fundamental frequency of a vowel after a stop. The values of these cues are plotted in the two and three dimensional space and see what the critical cues are for complete separation of different types of stops. Correlation coefficient analyses show that there are statistically significant relationships among acoustic cues but they are not strong enough to make a conjecture that there is a possible articulatory relationship among the mechanisms employed by the acoustic cues.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.47-52
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• 2014

This study investigated how the degree of attention modulates English learners' perception of Korean stop contrasts. The contributions of VOT and F0 in perceiving Korean stops were examined while availability of attentional resources was manipulated using a dual-task paradigm. Results demonstrated the attentional modulation in the use of VOT, but not in F0: under less attention, the contribution of VOT to the perception of aspirated stops decreased, whereas that of lenis stops increased, which suggests more native-like performance. This implies that the role of attention in perceiving non-native contrasts might differ depending on how equivalent the acoustic and perceptual cues are between L1 and target L2 contrasts.

• MALSORI
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• no.38
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• pp.125-136
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• 1999

This study examined the perception and production of Korean lax, fortis and aspirated stops in three apraxic patients. All of tile subjects made more production errors than perception errors. This indicates that apraxic patients have problems in phonetic execution rather than phonological representation. Additionally, in both production and perception, there were more errors in non-word-initial consonants than in word-initial consonants. These findings contradict those of the previous studies which report more errors in word-initial consonants. This study also found that, unlike previous studies in the types of errors made, distortion errors were high in both non-word-initial and word-initial consonants in apraxic patients. Generally, VOT of the stops showed significant differences among lax, fortis, and aspirated stops, which indicates that there is a failure not in choosing the appropriate stop but in positioning or motor planning at the articulation stage.