• 대한음성학회:학술대회논문집
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• 대한음성학회 2007년도 한국음성과학회 공동학술대회 발표논문집
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• pp.217-220
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• 2007

This study outlines a small-sized dialog style ETRI Korean TTS system which applies a HMM based speech synthesis techniques. In order to build the VoiceFont, dialog-style 500 sentences were used in training HMM. And the context information about phonemes, syllables, words, phrases and sentence were extracted fully automatically to build context-dependent HMM. In training the acoustic model, acoustic features such as Mel-cepstrums, logF0 and its delta, delta-delta were used. The size of the VoiceFont which was built through the training is 0.93Mb. The developed HMM-based TTS system were installed on the ARM720T processor which operates 60MHz clocks/second. To reduce computation time, the MLSA inverse filtering module is implemented with Assembly language. The speed of the fully implemented system is the 1.73 times faster than real time.

• 한국음향학회지
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• 제18권8호
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• pp.3-8
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• 1999

문맥독립형 음향모델을 채택하고 있는 기존의 가변어휘 음성인식기는 주변환경에 따른 음소의 변화를 모델링 할 수 없었다. 이러한 문제를 해결하기 위해서는 변이음을 이용한 문맥의존형 음향모델을 사용해야 한다. 본 논문은 가변어휘 음성인식기의 음향모델을 효과적으로 개선하기 위하여 적용한 방법에 대해서 기술하고 있다. 즉, 음향모델의 개선은 엔트로피를 이용한 군집화 기법을 적용하여 변이음의 개수를 변경시키면서 최적의 변이음 모델을 추출하는 방법을 사용하였다. 개선된 모델에 대한 성능은 POW(Phonetically Optimized Words) 3848 DB 및 SNR이 크게 다른 2종류의 PC168 DB를 이용하여 훈련 및 인식 실험을 수행하면서 평가하였다. 결론적으로 변이음의 개수를 낮추면서도 인식 성능의 저하를 가져오지 않는 최적의 변이음 모델을 얻을 수 있었으며 PC168 DB를 이용한 인식실험을 통하여 확인할 수 있었다.

• 말소리와 음성과학
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• 제9권3호
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• pp.7-15
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• 2017

The purpose of this study was to investigate the different aspects of word-initial liquid sounds in Korean according to generations. Five women in their 50s and seven in their 20s participated in the experiment. We examined FL (formant of liquids) and voice sustained time by using Praat software. Three English native speakers were asked to judge the Korean speakers' recorded speech samples for marking [l] or [r] using evaluation sheet. The results of the two experiments revealed three important aspects. First, there was a statistically significant difference between the two groups in the FL of the words 'racket' and 'ruby.' Second, we found statistically significant differences in 'rhythm', 'ruby' and 'litter' from the measurement of the duration of the acoustic data. Third, there was no difference in pronunciation between the two groups according to the phonemes of the original language. The results of this study showed that it is difficult to say that the duration of word-initial liquids and the phoneme difference of the original language are indicators to distinguish the word-initial liquids between generations. Also, it was seen that the pronunciation of Korean word-initial liquid sounds varied across generations.

• 한국음향학회지
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• 제6권2호
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• pp.30-37
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• 1987

한글 단모음의 음향특성을 기본진동수와 배진동수를 고러하여 포만트 분석하였으며, 성도내의 공명현상과 포만트진동수와의 상관관계를 고찰하였다. 성악을 전공하는 남성으로 하여금 한글 단모음 12개를 5개의 기본진동수에 맞추어 3초 동안 발음하게 하여 FFT스펙트럼 분석기를 통해 진동수 스펙트럼을 얻었다. 포만트 분석에 의해 제 1포만트는 인두강, 그리고 제 2포만트는 구강의 공명효과에 의함을 밝혔고, 원순화가 일어나므로서 제 2포만트 진동수가 낮아짐을 발견하였다. 제 1포만트와 제 2포만트 진동수로는 "어"의 $[\partial]와[\Lambda], "아"의[a]와 [\alpha]$, 그리고"에"와 "애"의 음향학적 차이를 뚜렷이 구분짓기는 어러웠다

• 대한음성학회:학술대회논문집
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• 대한음성학회 2000년도 7월 학술대회지
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• pp.353-363
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• 2000

The consonant system of English is relatively uniform throughout the English-speaking countries. Accents of English are mainly known to differ in terms of their vowel systems as well as in the phonetic realisations of vowel phonemes. The results of an acoustic study of vowel phonology of Japanese English, Singapore English and Indian English are presented, and an attempt is then made to compare the vowel phonology of these non-native varieties with that of Scottish English and RP. Various native varieties of English are thus shown to differ from each other in major ways, as much, perhaps, as the non-native varieties differ from the native varieties. Nevertheless, native speakers of English appear to be mutually intelligible to a degree that does not extend to non-native varieties. Obviously there are features that various native accents have in common which facilitate their mutual intelligibility, and these features are not shared by non-native accents. It is proposed that the foreign learner adopt certain core features of English in his pronunciation if he is to use English effectively as an international language. The common core that is significant in the communication process will be discussed. In conclusion, some pragmatic implications for the English language education in the new millennium will be articulated.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2006년도 추계학술대회 발표논문집
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• pp.80-83
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• 2006

The purpose of this paper is to build a pronunciation lexicon with estimated likelihoods of the phonetic rules based on the phonetic realizations and therefore to improve the performance of CSR using the dictionary. In the baseline system, the phonetic rules and their application probabilities are defined with the knowledge of Korean phonology and experimental tuning. The advantage of this approach is to implement the phonetic rules easily and to get stable results on general domains. However, a possible drawback of this method is that it is hard to reflect characteristics of the phonetic realizations on a specific domain. In order to make the system reflect phonetic realizations, the likelihood of phonetic rules is reestimated based on the statistics of the realized phonemes using a forced-alignment method. In our experiment, we generates new lexica which include pronunciation variants created by reestimated phonetic rules and its performance is tested with 12 Gaussian mixture HMMs and back-off bigrams. The proposed method reduced the WER by 0.42%.

• 말소리와 음성과학
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• 제10권2호
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• pp.85-96
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• 2018

The purpose of this study was to investigate the effect of articulatory intervention using visual phonics to improve the speech intelligibility of children with impaired hearing. The subjects of the study were five hearing impaired children. As per the results of the UTAP articulation tests, five phonemes with the most frequent errors were selected for each child and a total of 10 sessions were provided. The methodology involved analyzing vowel space and related measures (vowel space area, vowel articulatory index, formant centralization ratio, and F2i/F2u ratio) before and after the visual phonics intervention. After the articulation intervention, every child's speech intelligibility improved, their vowel space area was widened, the FCR value decreased, and the F2ratio value increased. These results show that the use of visual phonics through symbolic images and hand clues has a positive effect in terms of improving the speech intelligibility of children with impaired hearing.

• 말소리와 음성과학
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• 제10권2호
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• pp.15-24
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• 2018

Earlier studies reported that the /o/ and /u/ phonemes of Seoul Korean were currently merging in the F1/F2 space. However, studies on perception tests have shown that rates of correctness were high, even in cases where the two vowels overlapped. This study explores whether there is another acoustic parameter that differentiates /o/ from /u/, besides the F1/F2 contrast. Seventy-five native speakers of Seoul Korean, born between 1953 and 1999, participated in a production test. The data collected were analyzed in terms of F1 and F2, H1-H2, and F0. The result shows that the /o/ and /u/ of female speakers almost overlap in the F1/F2 space for all ages, while H1-H2 values are significantly different between the two vowels regardless of age. On the other hand, the /o/ and /u/ of male speakers are largely well separated in the F1/F2 space, while the H1-H2 values between the two vowels are very close at all ages. F0 effect is relatively small for both male and female speakers, even though there is a statistically significant difference. The result of this study provides evidence that female speakers use phonation differences to distinguish /o/ from /u/, and that the F1/F2 contrast has been replaced by H1-H2 values.

• 한국컴퓨터정보학회논문지
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• 제20권12호
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• pp.145-152
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• 2015

In this paper, a standardized phonological rule should be embodied for all people who want to use Hangul beyond nationality. This researcher suggested a phonological process protocol in unicode for the purpose of developing a computer system-based program as one of methods to pronounce Hangul correctly. First of all, to solve a problem of standardizing Hangul pronunciation, it is necessary to develop a phonological process system. In other words, when a mobile phone or a keyboard is used, inputted strings should be changed exactly by an automatic device made according to the phonological rule. For this, a phonological process table is the most important and unicode which digitalizes Hangul is the most effective. Therefore, the purpose of this study is to complete a phonological process table, suggest an algorithm by the table, and develop a computer program pursuing correct Hangul pronunciation. For the methodology of this study, the features of unicode was used to solve a problem of coding each syllable by phonemes after strings were inputted from the phonological process program. This study suggested a protocol that sounds of inputted strings were automatically changed via recombination using a phonological process table. The ultimate purpose of the study was to help pronounce Hangul correctly according to the pronunciation rule.

• 음성과학
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• 제8권4호
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• pp.99-107
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• 2001

The purpose of this study was to investigate the syllable and phoneme frequencies in the spontaneous speech of some Korean children. Sixty four normally developing children aged from 2 to 5 were involved (male: female=1 : 1, 16 children in each age group). Fifty connected utterances were analyzed using the KCLA (Korean Computerized Language Analysis) 2.0 and Exel. The findings were as follows: 1) /i/ was the most frequently used syllable and was followed by /yo/, /k/, /s'/, /nen/ and so on. 2) The most frequently used Korean phonemes were syllable-initial consonant /k/, syllable- medial vowel /a/ and syllable-final consonant /n/. 3) All seven syllable final consonants (/p,t,k,m,n,n,l/) were used more frequently in the word-medial position than in the word-final position. Three syllable initial consonants(/k, I, s'/) were used more frequently in the word-medial position than in the word-initial position. The syllable and phoneme frequencies in the Korean children's spontaneous speech will provide valuable information in interpreting the severity of phonological disorder and in developing tools for the Korean phonological assessment and intervention.