• 대한음성학회지:말소리
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• 제33_34호
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• pp.99-110
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• 1997

This paper aims to investigate the internal structure of the pre-nuclear intonation pattern and to discuss the inventory and usage of the phrasal tone in Korean based on the acoustic analysis of 80 test sentences. CSL Model 4300 was used for recording and filing, and Multi-speech Model 3700 for analysis. It is shown that the pre-nuclear intonation pattern is composed of one or more phrasal tones, the intonation pattern of the rhythm nit. It is observed that the second phrasal tone begins with a higher pitch than the first one and that the phrasal tones following the second one begins with a lower pitch than the preceding phrasal tone unless a certain word is emphasized. In addition to Level, Rising, Falling, and Rise-Fall phrasal tones already established in Lee (1990, 1991, 1996), Pall-Rise and Rise-Fall-Rise phrasal tones are newly established in this paper. It is observed that Rising and Rise-Fall-Rise phrasal tones are most frequently used as the first phrasal tone of a pre-nuclear intonation pattern and the falling tone as the last phrasal tone, and that Fall-Rise and level tones appear most frequently in the middle of a pre-nuclear intonation pattern.

• 말소리와 음성과학
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• 제4권2호
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• pp.95-104
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• 2012

Thyroidectomy patients may have vocal paralysis or paresis, resulting in a breathy voice. The aim of this study was to investigate the aerodynamic and acoustic characteristics of a breathy voice in thyroidectomy patients. Thirty-five subjects who have vocal paralysis after thyroidectomy participated in this study. According to perceptual judgements by three speech pathologists and one phonetic scholar, subjects were divided into two groups: breathy voice group (n = 21) and non-breathy voice group (n = 14). Aerodynamic analysis was conducted by three tasks (Voicing Efficiency, Maximum Sustained Phonation, Vital Capacity) and acoustic analysis was measured during Maximum Sustained Phonation task. The breathy voice group had significantly higher subglottal pressure and more pathological voice characteristics than the non breathy voice group. Showing 94.1% classification accuracy in result logistic regression of aerodynamic analysis, the predictor parameters for breathiness were maximum sound pressure level, sound pressure level range, phonation time of Maximum Sustained Phonation task and Pitch range, peak air pressure, and mean peak air pressure of Voicing Efficiency task. Classification accuracy of acoustic logistic regression was 88.6%, and five frequency perturbation parameters were shown as predictors. Vocal paralysis creates air turbulence at the glottis. It fluctuates frequency-related parameters and increases aspiration in high frequency areas. These changes determine perceptual breathiness.

• 말소리와 음성과학
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• 제7권3호
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• pp.99-105
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• 2015

The current study investigates whether Korean-speaking adults show differential sensitivities to the sources of auditory stimuli (L1 Korean and L2 English) in utilizing VOT and f0 in the perceptual mode of L2 stops, and how the L2 proficiency interacts with the learners' low-level phonetic sensitivities in L2 perceptual mode. 48 Korean learners of English participated in the perception experiments where they rated the goodness of English /t/ and /d/ using an analogue scale. Two sets of stimuli (English and Korean sources) were prepared by manipulating VOT (6-steps) and f0 (5-steps) values of productions by an English male (L2 source condition) and a Korean male (L1 source condition). Findings showed that, in judging /t/-likeness, the listeners responded differently to the two auditory stimulus conditions by relying on VOT significantly more in English source condition than in Korean source condition. The listeners' English proficiency did not interact with these differential sensitivities to the auditory stimulus source either along the VOT dimension or the f0 dimension. The results of the current study suggest that low-level contextual information of the auditory source can affect the learners in faithfully being in the L2 perceptual mode.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2006년도 추계학술대회 발표논문집
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• pp.99-108
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• 2006

Three experiments were conducted to determine the exact locus of the frequency effect in speech production. In Experiment 1. a picture naming task was used to replicate whether the word frequency effect is due to the processes involved in lexical access or not. The robust word frequency effect of 31ms was obtained. The question to be addressed in Experiment 2 is whether the word frequency effect is originated from the level where a lemma is selected. To the end, using a picture-word interference task, the significance of interactions between the effects of target frequency, distractor frequency and semantic relatedness were tested. Interaction between the distractor frequency and semantic relatedness variables was significant. And interaction between the target and distractor frequency variables showed a significant tendency. In addition, the results of Experiment 2 suggest that the mechanism underlying the word frequency effect is encoded as different resting activation level of lemmas. Experiment 3 explored whether the word frequency effect is attributed to the lexeme level where phonological information of words is represented or not. A methodological logic applied to Experiment 3 was the same as to Experiment 2. Any interaction was not significant. In conclusion, the present study obtained the evidence supporting two assumptions: (a) the locus of the word frequency effect exists in the processes involved in lemma selection, (b) the mechanism for the word frequency effect is encoded as different resting activation level of lemmas. In order to explain the word frequency effect obtained in this study, the core assumptions of current production models need to be modified.

• 말소리와 음성과학
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• 제2권2호
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• pp.3-16
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• 2010

This study aims at setting the hierarchy of difficulty of the 7 Korean monophthongs for Mongolian learners of Korean according to Prator's theory based on the Contrastive Analysis Hypothesis. In addition to that, it will be shown that the difficulties and errors for Mongolian learners of Korean as a second or foreign language proceed directly from this hierarchy of difficulty. This study began by looking at the speeches of 60 Mongolians for Mongolian monophthongs; data were investigated and analyzed into formant frequencies F1 and F2 of each vowel. Then, the 7 Korean monophthongs were compared with the resultant Mongolian formant values and are assigned to 3 levels, 'same', 'similar' or 'different sound'. The findings in assessing the differences of the 8 nearest equivalents of Korean and Mongolian vowels are as follows: First, Korean /a/ and /$\wedge$/ turned out as a 'same sound' with their counterparts, Mongolian /a/ and /ɔ/. Second, Korean /i/, /e/, /o/, /u/ turned out as a 'similar sound' with each their Mongolian counterparts /i/, /e/, /o/, /u/. Third, Korean /ɨ/ which is nearest to Mongolian /i/ in terms of phonetic features seriously differs from it and is thus assigned to 'different sound'. And lastly, Mongolian /$\mho$/ turned out as a 'different sound' with its nearest counterpart, Korean /u/. Based on these findings the hierarchy of difficulty was constructed. Firstly, 4 Korean monophthongs /a/, /$\wedge$/, /i/, /e/ would be Level 0(Transfer); they would be transferred positively from their Mongolian counterparts when Mongolians learn Korean. Secondly, Korean /o/, /u/ would be Level 5(Split); they would require the Mongolian learner to make a new distinction and cause interference in learning the Korean language because Mongolian /o/, /u/ each have 2 similar counterpart sounds; Korean /o, u/, /u, o/. Thirdly, Korean /ɨ/ which is not in the Mongolian vowel system will be Level 4(Overdifferentiation); the new vowel /ɨ/ which bears little similarity to Mongolian /i/, must be learned entirely anew and will cause much difficulty for Mongolian learners in speaking and writing Korean. And lastly, Mongolian /$\mho$/ will be Level 2(Underdifferentiation); it is absent in the Korean language and doesn‘t cause interference in learning Korean as long as Mongolian learners avoid using it.

• 대한치과보철학회지
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• 제30권3호
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• pp.338-360
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• 1992

This study was performed to investigate the phonetic alterations with upper anterior teeth were missing. To compare the changes of the phonations, before and after insertion of the temporary prosthesis, six subjects who lost their upper anterior teeth were selected (2-male, 4-female). Tested sounds (/ga(가), na(나), da(다), ra(라), sa(사), ja(자), cha(차), ta(타), pa(파), ha(하), gi(기), ni(니), di(디), ri(리), si(시), jl(지), chi(치), ti(티), pi(피), hi(히), seu(스), se(세), so(소), su(수)/were programmed into an IBM AT with and without temporary prosthesis. These experiments were analyzed by formants, consonants durations, and energy level changes with an LSI speech work station program. During the pronunciation of the tested sounds (with and without temporary prosthesis), mandibular movements were recorded to a Mandibular Kinesiogram and analyzed . The findings led to the following conclusions: 1. Objective differences could not be found. However, in every informant, subjective improvement could be noticed. 2. There were no persistant correlations of the formant's changes. And in every informant, phonetic changes were variable. 3. There were various changes of the consonant durations in every informant. By and large, those of /si(시), jl(지), chi(치), Pi(피), hi(히)/ were longer than other tested sounds. After insertion of the prosthesis, durations were shorter. Consonants with /i(ㅣ)/ were longer than with /a(ㅏ)/, with or without prosthesis. 4. With and without temporary prosthesis, mandibular movements were various in the frontal view. Mandibular movements showed lateral deviations, and mandibular positions with /si(시), ji(지), ti(티), seu(스), hi(히)/ were nearer to the mandibular rest position. 5. The kinds of temporary prosthesis and conditions of the missing teeth influenced every informant variously, so there were no correlation between informants. 6. Energy levels increased in all tested sounds with a fixed temporary prosthesis. And, there were no differences between before and after insertion of a removable temporary prosthesis. However, sibilant sounds, and consonants with /i(ㅣ)/ showed a little increased energy level.

• 음성과학
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• 제9권3호
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• pp.185-200
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• 2002

The current study confirmed the existence of an ip prosodic level in French intonation structure, as previously proposed by Sun-Ah Jun & $C\acute{e}cile$cile Fougeron (2000). However, in contrast to the previous suggestion of the plateau realized in an ip in several syntactic structures, the current study supposed that the plateau doesn't come from the different type of syntactic structures but arise from the unspecified syllables without any PA in an ip. Because if we limited ip phrasal tone to the syntactic structure, it would be difficult to find the more general reasons of ip level. Besides /Hi/ and /$H^*$/ we also used /$Hi^*$/ for the focused syllable in the current study. In emphasized sentences, in general, /$Hi^*$/ appeared in the first or second syllable of a leftward AP in an ip and /$H^*$/ in the final syllable of a rightmost AP of an ip, In contrast to these PAs, /$Hi^*$/ might appear in any syllable in an ip, but not to far from /$H^*$/ because the duration time and length t of plateau realized between /$Hi^*$/ and /$H^*$/ or /Hi/ and /$H^*$/ would make an essential harmonious rhythmic unit, Therefore, the current study determined the duration time and the number of syllables realized in each plateau in an ip level composed of more than one AP. As a phrase constituent structure, there is a practical need for intermediate prosodic units to allow for generalization over the many possible combinations of prosodic patterns that can occur. Further evidence is still needed to analyze and relate the different pitch ranges of the plateau of an ip according to the syntactic structure, to identify the considerable character in the French prosodic hierarchy.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2004년도 춘계 학술대회 발표논문집
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• pp.231-234
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• 2004

This paper describes an efficient method for improving the noise-robustness in speech recognition in a running car by considering wind noise. In driving car, mainly three kind of noises engine noise, tire noise and wind noise, are severely affect recognition performance. Especially wind noise is an important factor in driving car with window opened. We analyzed wind noise in various driving conditions that are 60, 80, 100 km/h with window fully opened, window half opened. We clarified that the recognition rate is significantly degenerated when the wind noise components in the frequency range above 200 Hz are large. We developed a preprocessing method to improve the noise robustness despite of wind noise. We adaptively changed the cutoff frequency of the front-end high-pass filter from 100 through 200 Hz according to the level of the wind noise components. By this method, the recognition rate is considerably improved for all kind of driving conditions

• 한국음향학회지
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• 제19권6호
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• pp.28-33
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• 2000

낱말 내에서 선행음절말-후속음절초로 연이어 나타나는 일종의 쌍자음(geminate)의 지속시간 차이를 고찰하고자 한다. (ㅁ-ㅁ) 연쇄와 (ㄴ-ㄴ) 연쇄를 중심으로 논의하였다. 한 낱말 내에서 선행하는 양순 비음 (ㅁ)과 이를 뒤따르는 양순 비음(ㅁ) 사이에 통계적으로 유의한 차이는 없다고 볼 수 있으나, 선행하는 자음의 지속시간이 약간 짧아지는 경향이 관찰되었다. 치조비음 (ㄴㄴ) 연쇄의 경우, 전반적으로, 한 낱말 내에서 선행하는 치조 비음과 이를 뒤따르는 치조 비음 사이에는 통계적으로 차이가 있으며, 선행하는 자음의 지속시간이 좀 더 길어지는 경향이 있다고 정리할 수 있다.

• 음성과학
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• 제6권
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• pp.197-217
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• 1999

In a noisy class, the acoustic-phonetic features of the teacher and the perceptual features of learners are changed comparison with a quiet environment. Acoustical analyses were carried out on a set of French monosyllables consisting of 17 consonants and three vowel /a, e, i/, produced by 1 male speaker talking in quiet and in 50, 60 and 70 dB SPL of masking noise on headphone. The results of the acoustic analyses showed consistent differences in energy and formant center frequency amplitude of consonants and vowels, $F_1$ frequency of vowel and duration of voiceless stops suggesting the increase of vocal effort. The perceptual experiments in which 18 undergraduate female students learning French served as the subjects, were conducted in quiet and in 50, 60 dB of masking noise. The identification scores on consonants were higher in Lombard speech than in normal speech, suggesting that the speaker's vocal effort is useful to overcome the masking effect of noise. And, with increased noise level, the perceptual response to the French consonants given had a tendency to be complex and the subjective reaction score on the noise using the vocabulary representative of 'unpleasant' sensation to be higher. And, in the point of view on the L2(second language) acquisition, the influence of L1 (first language) on L2 examined in the perceptual result supports the interference theory.