• 전자공학회논문지
• /
• 제53권3호
• /
• pp.143-150
• /
• 2016

본 논문에서는 안면근육 표면근전도를 기반으로 근육 조합 최적화를 통한 한국어 단모음 인식 방법을 제안한다. 표면근전도 신호는 한국어 단모음 발음에 따라 서로 다른 패턴과 근육 활성도를 보였다. 이전 연구에서 높은 인식 정확도를 보였던 RMS, VAR, MMAV1, MMAV2와 Cepstral Coefficients를 특징 추출 알고리즘으로 사용하였으며, QDA(Quadratic Discriminant Analysis)와 HMM(Hidden Markov Model)으로 한국어 단모음을 분류하였다. 트레이닝 단계에서 입력 받은 데이터로 근육조합을 최적화하고, 최적화 결과를 인식단계에 적용한다. 이때, 새로운 근전도 신호를 입력받고 한국어 단모음을 최종 인식한다. 실험결과 제안한 방법의 인식 정확도가 QDA에서 평균 85.7%, HMM에서 평균 75.1%를 보였다.

• 대한음성학회:학술대회논문집
• /
• 대한음성학회 2003년도 10월 학술대회지
• /
• pp.51-53
• /
• 2003

The Korean diphthong /je/ is realized monophthong /e/ or neutralized /E/ in real speech generally. And diphthong /je/ was changed by preceeding consonants and place of syllable. In case that preceeding consonants exist, /je/ is realized as it is /je/, but in case that preceeding consonants don't exist, /je/ is changed variously. In case that /je/ is in second syllable place, /je/ is realized monophthong /e/ and in case that /je/ is in fist syllable place, /je/ is realized diphthong /je/.

• 말소리와 음성과학
• /
• 제10권1호
• /
• pp.65-74
• /
• 2018

The purpose of this study is to investigate age-specific features of 2;1- to 4;1-year -olds' production of monophthongs and diphthongs through both auditory perceptual analysis and acoustic analysis. Test material included {vowel+'da'} consisting of 7 monophthongs and 10 diphthongs and meaningful words beginning with vowels. The percentage of correct vowels was used for perceptual analysis and Praat(5.2.12) was used for acoustic analysis, analyzing variables related to monophthongs and diphthongs. The results of this study are as follows: First, perceptual analysis showed that children from an age group of 2;1 to 2;8 years showed significant difference in the accuracy level of both monophthongs and diphthongs as compared to those aged 2;9 to 3;4 years and those aged 3;5 to 4;1 years. Second, the results of acoustic analysis provided that formant (F1 and F2) of monophthong, in general, tended to decrease as age increased. In terms of F2 differentiation slope and regression slope, which were diphthong-related variables, the age group of 3;5 to 4;1 years showed a large general slope change.

• 말소리와 음성과학
• /
• 제8권4호
• /
• pp.39-47
• /
• 2016

While acoustic studies in the past decade documented a raised /o/ by showing their lowered first formants (F1) almost overlapped with those of high back vowel /u/, no consensus has been made in terms of how this /o/-raising affects the vowels as a system in Seoul Korean. The current study aimed to investigate the age- and gender-related differences of the relative distance among the vowels to better understand the influence of this on-going sound change on the vowel system. We measured the static and dynamic spectral characteristics (F1 and F2) of the seven Korean monophthong vowels /e a ʌ o u ɨ i/ in the spontaneous speech of Seoul Corpus, and depicted the patterns of 30 individual speakers (10 speakers in each group of teens, 20s and 40s) as a function of age and gender. The static spectral examination showed low F1 values of /o/ in the spontaneous speech corpus confirming the vowel /o/ raising, and also revealed greater F2 values of /u, ɨ/ suggesting their anterior articulations. The tendencies were stronger when the speakers were younger and female. The spectral trajectories further showed that the F1 and F2 between /o/ and /u/ were differentiated throughout the vowel mid-point although the trajectories gradually merged near the vowel mid point in the older male speakers' productions. The acoustic evidence of contrast among /o, u, ɨ/ supports that the raised /o/ is not indicative of a merger with /u/ but rather implying a chain-like vowel shift in the Seoul Korean.

• 말소리와 음성과학
• /
• 제5권1호
• /
• pp.73-80
• /
• 2013

Formant is one of the essential vocal features for research of voice production, recognition and synthesis. Numerous studies were established on foreign languages including English vowels. However, studies related to Korean were done with a limited number of voice data. In this study, we compare four formants according to age and gender using a large number of Korean monophthongs. A total of 2614 Korean speakers participated in our experiments. We summarize statistical results by mean and standard deviation for each formant of five monophthongs. The results show a notable difference in each age and gender group. A quantitative study based on a large dataset is suggested for future studies on Korean speech sounds.

• 말소리와 음성과학
• /
• 제6권3호
• /
• pp.139-145
• /
• 2014

The paper describes methods of conducting vowel analysis from a large-scale corpus with the aids of forced alignment and optimal formant ceiling methods. 'Read Style Corpus of Standard Korean' is used for building the forced alignment system and a subset of the corpus for the processing and extraction of features for vowel analysis based on optimal formant ceiling. The results of the vowel analysis are reliable and comparable to the results obtained using traditional analytical methods. The findings indicate that the methods adopted for the analysis can be extended and be used for more fine-grained analysis without time-consuming manual labeling without losing accuracy and reliability.

• 대한음성학회:학술대회논문집
• /
• 대한음성학회 2005년도 추계 학술대회 발표논문집
• /
• pp.185-188
• /
• 2005

We presents a new method for the measurement and analysis of the volume of the vocal tract using 3D magnetic resonance image. The relative ratios of volume A, B, and C, which are divided by the 2constriction points formed on the horizontal and vertical plane in vocal tract, take a decisive role indiscriminating Korean monophthong. Together with Fl-F2 and the minimum cross sectional area in the vocal tract, the relative ratios of the regional volumes were proved to be significant parameter in statistic viewpoint.

• 한국어학
• /
• 제80권
• /
• pp.211-234
• /
• 2018

This study aims to research the acoustic properties of Korean and Vietnamese monophthongs by Vietnamese advanced Korean learners, and to discuss the realization of Korean monophthongs compared to Koreans. The Vietnamese advanced Korean learners do not distinguish between /e/ and /${\varepsilon}$/, which are the same as Korean. They pronounce Korean /e(${\varepsilon}$)/ close to /e/ in their native language. In the case of /ʌ/, it is reported that many errors are observed in previous studies. However, /ʌ/ of Vietnamese advanced learners is realized similar to /ʌ/ spoken by Koreans. /ɯ/ of Vietnamese advanced Korean learners is pronounced in the back of the tongue, whereas in the central by Koreans. In the case of /o/ and /u/, there is no significant difference by the Vietnamese advanced Korean learners. /ɯ/ and /u/ are pronounced in relatively front side of the tongue in Korean, but it is not observed in the Vietnamese advanced Korean learners.

• 말소리와 음성과학
• /
• 제6권1호
• /
• pp.31-38
• /
• 2014

The current study presents an instrumental phonetic analysis of Korean monophthong vowels in the early twentieth century Seoul Korean, based on audio recordings of elementary school textbooks Botonghakgyo Joseoneodokbon (Korean Reading Textbook for Elementary School). The data examined in this study were a list of the Korean mono syllables (Banjeol), and a short passage, recorded by one 41-year-old male speaker in 1935, as well as a short passage recorded by one 11-year-old male speaker in 1935. The Korean monophthongs were examined in terms of acoustic analysis of the vowel formants (F1, F2) and compared to those recorded by 18 male speakers of Seoul Korean in 2013. The results show that in 1935, 1) /e/ and /ɛ/ were clearly separated in the vowel space; 2) /o/ and /u/ were also clearly separated without any overlapping values; 3) some tokens of /y/ and /ø/ were produced as monophthongs, not as diphthongs. Based on the results, we can observe the historical change of the Korean vowels over 80-90 years such as 1) /e/ and /ɛ/ have been merged; and 2) /o/ has been raised and overlapped with /u/.

• 말소리와 음성과학
• /
• 제5권3호
• /
• pp.39-46
• /
• 2013

This study examined the perception of two Korean vowels using F1/F2 manipulated synthetic vowels. Previous studies indicated that there is an overlap between the acoustic spaces of Korean /o/ and /u/ in terms of the first two formants. A continuum of eleven synthetic vowels were used as stimuli. The experiment consisted of three tasks: an /o/ identification task (Yes-no), an /u/ identification task (Yes-no), and a forced choice identification task (/o/-/u/). ROC(Receiver Operating Characteristic) analysis and logistic regression were performed to calculate the boundary criterion of the two vowels along the stimulus continuum, and to predict the perceptual judgment on F1 and F2. The result indicated that the location between stimulus no.5 (F1 = 342Hz, F2 = 691Hz) and no.6 (F1 = 336Hz, F2 = 700Hz) was estimated as a perceptual boundary region between /o/ and /u/, while stimulus no.0 (F1=405Hz, F2=666Hz) and no.10 (F1=321Hz, F2=743Hz) were at opposite ends of the continuum. The influence of F2 was predominant over F1 on the perception of the vowel categories.