• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.37-52
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• 2011

This study investigates patterns of the alignment of the accentual peaks in bisyllabic words of the CVNCV, CVNV, and CVNNV structures in North Kyungsang Korean. Based on the tonal alignment, patterns of the F0 pitch excursion are discussed relative to one another. Issues are addressed concerning how the tonal targets are aligned, and how the tonal specifications of nasals in postvocalic, intervocalic, and prevocalic environments are supplied in the LH, HL, and HH classes. Tonal specification of nasals in various environments is accounted for by extension of the L target, displacement of the pitch peak, and interpolation between two tonal targets, depending on the tonal class. The results in this study provide preliminary evidence that the categorical alignment of the tonal targets is implemented by simply checking the presence or absence of a nasal before or after the nucleus vowel on the segmental string, without reference to the constituency of the nasal in the syllable structure. However, the prosodic structure has a key role to play in explaining speaker-dependent variations in the tonal alignment. Sensitivity to tautosyllabicity has an effect on the shape of the F0 contour, and disparity in the patterns of the pitch excursion is represented as a function of syllable structure correlated with segmental composition of the nasal.

• Phonetics and Speech Sciences
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• v.10 no.2
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• pp.45-50
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• 2018

The vowel/consonant ratio is a well-known cue for the voicing of postvocalic consonants. This study investigates how this ratio changes as a function of speaking rate. Seven speakers of North American English read sentences containing target monosyllabic words that contrasted in coda voicing at three different speaking rates. Duration measures were taken for the voice onset time (VOT) of the onset consonant, the vowel, and the coda. The results show that the durations of the onset VOT and vowel are longer before voiced codas, and that the durations of all segments increase monotonically as speaking rate decreases. Importantly, the vowel/consonant ratio, a primary acoustic cue for coda voicing, was found to pattern asymmetrically for voiced and voiceless codas; it increases for voiced codas but decreases for voiceless codas with the decrease in speaking rate. This finding suggests that there is no stable ratio in the duration of preconsonantal vowels that is maintained in different speaking styles.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.103-113
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• 2016

This paper aims to propose articulatory features as novel predictors for automatic pronunciation assessment of English produced by Korean learners. Based on the distinctive feature theory, where phonemes are represented as a set of articulatory/phonetic properties, we propose articulatory Goodness-Of-Pronunciation(aGOP) features in terms of the corresponding articulatory attributes, such as nasal, sonorant, anterior, etc. An English speech corpus spoken by Korean learners is used in the assessment modeling. In our system, learners' speech is forced aligned and recognized by using the acoustic and pronunciation models derived from the WSJ corpus (native North American speech) and the CMU pronouncing dictionary, respectively. In order to compute aGOP features, articulatory models are trained for the corresponding articulatory attributes. In addition to the proposed features, various features which are divided into four categories such as RATE, SEGMENT, SILENCE, and GOP are applied as a baseline. In order to enhance the assessment modeling performance and investigate the weights of the salient features, relevant features are extracted by using Best Subset Selection(BSS). The results show that the proposed model using aGOP features outperform the baseline. In addition, analysis of relevant features extracted by BSS reveals that the selected aGOP features represent the salient variations of Korean learners of English. The results are expected to be effective for automatic pronunciation error detection, as well.

• Phonetics and Speech Sciences
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• v.11 no.3
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• pp.9-21
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• 2019

This study aimed to compare the prosodic characteristics of North Korean defectors and South Koreans in three types of sentences (declarative, interrogative, and negative) in two reading tasks (short and dialogue) through acoustic analysis and auditory-perceptual evaluation. In addition, this study examined the relationship between the auditory-perceptual evaluation scores and self-assessment questionnaires on intonation for North Korean defectors. The participants were 15 North Korean defectors and 15 Korean speakers with standard Seoul accents. For statistical analysis, three-way mixed ANOVA and multivariate analysis were performed within the three types of sentences in the reading tasks through acoustic analysis and the Mann-Whitney U Test for auditory-perceptual evaluation. Pearson's product-moment correlation coefficients were also used to identify the correlations between the results of the self-assessment questionnaire on intonation and the auditory-perceptual evaluation. The North Korean defectors were found to have a significantly lower pitch range and auditory-perceptual evaluation score than South Koreans in reading tasks. Moreover, there was a significant correlation between their auditory-perceptual evaluations and self-assessment questionnaires on intonation. The study findings suggest that North Korean defectors, who face many challenges with intonation, showed a tendency to think that their intonation differed from the standard Korean intonation and showed better auditory evaluation results for interrogative sentences.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.25-33
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• 2022

This study investigates the relationships between rhythm and fluency indices and listeners' ratings of the rhythm and fluency of Korean college students' English paragraph reading. 17 university students read and recorded a passage from "The North Wind and the Sun" twice before and after three months of English pronunciation instruction. Seven in-service and pre-service English teachers in graduate school assessed the rhythm and fluency of the utterances. In addition, the values of 14 indices of rhythm and fluency were extracted from each speech and the relationships between the indices and the listeners' ratings were analyzed. The rhythm indices of the speakers in this study did not differ significantly from those of native English speakers presented in previous studies in %V, VarcoV, and nPVIV, but were higher in ΔV, ΔC, and VarcoC and lower in speech rate. The level of rhythm and fluency demonstrated by Korean college students was comparable, at least in terms of objective values for certain indices. The fluency indices, such as percentage of pauses, articulation rate, and speech rate, significantly contributed more to predicting both rhythm and fluency ratings than the rhythm indices.

• Phonetics and Speech Sciences
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• v.12 no.3
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• pp.41-53
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• 2020

A wh-phrase in an embedded sentence may have either an embedded or a matrix scope. Interpretation of a wh-phrase with a matrix scope has tended to be syntactically unacceptable unless the sentence reads with a wh-intonation. Previous studies have found two differences in prosodic characteristics between sentences with matrix and embedded scopes. Firstly, peak F0s in wh-phrases produced with an F0 compression wh-intonation are higher than those in indirect questions, and peak F0s in matrix verbs are lower than those in sentences with embedded scope. Secondly, a substantial F0 drop is found at the end of embedded sentences in indirect questions, whereas no F0 reduction at the same point is noticed in sentences with a matrix scope produced with a high plateau wh-intonation. However, these characteristics were not found in our experiment. This showed that a more compelling difference exists in the values obtained from subtraction between the peak F0s of each word (or a word plus an ending or case marker) and the F0s at the end of the word. Specifically, the gap between the peak F0 in a word composed with an embedded verb and the F0 at the end of the word, which is a complementizer in Korean, is large in embedded wh-scope sentences and low in matrix wh-scope sentences.