• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.39-47
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• 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.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.71-73
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• 2007

The Purpose of the study is to give Korean-English leaners better knowledge on vowel sounds in their learning English. The traditional description of the cardinal vowel system developed by Daniel Johns in 1917 is not enough to provide English learners with clear ideas in producing native like vowel sounds. For the reason, three Korean-native subjects, one male, one female and one child are chosen to produce 7 cardinal vowels and compare them with native English and American speaker's vowel sounds. The difference of produced vowels sounds is quantified and visualized by employing Sona-match program. The results have been fairly remarkable. Firstly, Korean-English learner's vowel sounds are articulated differently from their intention of vowel production. Secondly, the tongue positions of Koreans are placed slightly more down and forward to the lips than those of English and Americans. However, the front vowel /i/ sound is quite close to English and Americans. Lastly the mid-vowel /${\partial}$/ sound is not produced in any articulations of Korean-native speakers. It is thought that the mid vowel, /${\partial}$/ is a type of a weak sound regarded as 'schwa' which needs a great deal of exposure to the language to acquire a physical skill of articulation.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.45-50
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• 2011

Formant structure of speech associated with five different emotions (anger, fear, happiness, neutral, sadness) was analysed. Acoustic separability of vowels (or emotions) associated with a specific emotion (or vowel) was estimated using F-ratio. According to the results, neutral showed the highest separability of vowels followed by anger, happiness, fear, and sadness in descending order. Vowel /A/ showed the highest separability of emotions followed by /U/, /O/, /I/ and /E/ in descending order. The acoustic results were interpreted and explained in the context of previous articulatory and perceptual studies. Suggestions for the performance improvement of an automatic emotion recognition system and automatic speech recognition system were made.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.23-34
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• 2011

Many Korean children have difficulty learning English vowels. The gestures inside the oral and pharyngeal cavities are hard to control when they cannot see the gestures and the target vowel system is quite different from that of Korean. This study attempts to collect children's acoustic data of twelve English vowels published by Hillenbrand et al. (1995) online and to examine the acoustic features of English vowels for phoneticians and English teachers. The author used Praat to obtain the data systematically at six equidistant timepoints over the vowel segment avoiding any obvious errors. Results show inherent acoustic properties for vowels from the children's distribution of vowel duration, f0 and intensity values. Second, children's gestures for each vowel coincide with the regression analysis of all formant values at different timepoints regardless of the vocal fold and tract difference. Third, locus points appear higher than those of American males and females. Their gestures along the timepoints display almost similar patterns. From the results the author concludes that vowel formant trajectories provide useful and important information on dynamic articulatory gestures, which may be applicable to Korean children's education and correction of English vowels. Further studies on the developmental study of vowel formants and pitch values are desirable.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.1
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• pp.59-64
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• 2015

In this paper, we found the usefulness of the deep belief network (DBN) in the fields of brain-computer interface (BCI), especially in relation to imagined speech. In recent years, the growth of interest in the BCI field has led to the development of a number of useful applications, such as robot control, game interfaces, exoskeleton limbs, and so on. However, while imagined speech, which could be used for communication or military purpose devices, is one of the most exciting BCI applications, there are some problems in implementing the system. In the previous paper, we already handled some of the issues of imagined speech when using the International Phonetic Alphabet (IPA), although it required complementation for multi class classification problems. In view of this point, this paper could provide a suitable solution for vowel classification for imagined speech. We used the DBN algorithm, which is known as a deep learning algorithm for multi-class vowel classification, and selected four vowel pronunciations:, /a/, /i/, /o/, /u/ from IPA. For the experiment, we obtained the required 32 channel raw electroencephalogram (EEG) data from three male subjects, and electrodes were placed on the scalp of the frontal lobe and both temporal lobes which are related to thinking and verbal function. Eigenvalues of the covariance matrix of the EEG data were used as the feature vector of each vowel. In the analysis, we provided the classification results of the back propagation artificial neural network (BP-ANN) for making a comparison with DBN. As a result, the classification results from the BP-ANN were 52.04%, and the DBN was 87.96%. This means the DBN showed 35.92% better classification results in multi class imagined speech classification. In addition, the DBN spent much less time in whole computation time. In conclusion, the DBN algorithm is efficient in BCI system implementation.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.103-106
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• 2000

무제한 인식 시스템을 구현하기 위해서는 적절한 인식단위, 훈련 데이터 베이스의 확보, 인식단위의 분할, 인식 알고리즘과 같은 문제점을 모두 해결하여야 한다. 따라서 본 논문에서는 무제한 음성인식 시스템의 인식의 기본 단위로 모음의 안정구간을 검출하여 분할하는 CV(Consonant-Vowel), VC(Vowel-Consonant), VC CV(Vowel-Consonant-Consonant-Vowel)단위와 분할 파라미터를 제안하고, 분할 실험을 통해 그 유효성을 확인하고자 한다.

• Speech Sciences
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• v.8 no.1
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• pp.53-66
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• 2001

This paper aims to investigate the acoustic characteristics of the vowels attested in Korean and French and to seek a way of understanding them from a phonological point of view. We first compare the two vowel systems by measuring the actual frequencies of the formants using CSL. It is shown that the first and second formants vary in wider range in French compared to Korean. In order to understand the two vowel systems from a phonological point of view, we apply the theory of Licensing Constraints, proposed and developed by Kaye (1994), and Charette and Kaye (1994). We propose the licensing constraints placed upon the vowels both in Korean and French. For Korean, we propose the licensing constraints such that both elements I and U must be heads. For French, we claim the following licensing constraints: U in a headed expression must be head, A cannot be head, and Nothing can only license an expression A in it.

• MALSORI
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• no.39
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• pp.43-51
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• 2000

The aim of this paper is to present a phonetically oriented keyboard array for the International Korean Phonetic Alphabet (IKPA). IKPA is a phonetic alphabet devised on the basis of Hangout (Korean alphabet) (Lee, 1999). Every computer has a keyboard as its input device and the English keyboard array is hewn as 'QWERTY' system, which represents the first six letters of the second line of the keyboard. This array is a traditional one devised to protect the congestion of the keys of the mechanical typewriter. To improve the anay of the keyboard, another system named 'Dvorak' has been devised. Likewise, a serious attempt has been made by the authors to work out an efficient keyboard for IKPA representing the manner of vowel and consonant classification. In the phonetic keyboard, the consonant symbols are arranged in the left hand side according to the Place and mauler of the articulation and the vowel symbols in the right hand side according to the vowel quadrilateral.

• Journal of the Korean Society for Library and Information Science
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• v.1
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• pp.1-58
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• 1970

As to the structure of author tables for the Korean libraries using the Korean alphabet Hangul for filing, no other system is understood more relevant to author notations than the analytico-synthetic system. The Korean character consists of syllables respectively dividual into 'consonant+vowel' or 'consonant+vowel+consonant,' with the first element a consonant and the second a vowel. When these elements are synthesized with figure representation, they make an enumerative two-figure table. Individualizing and assigning, therefore, are done without listing many en-tries on the table or looking up notations in ready-made enumerative author tables. We still do not have general agreements in form of entry, reading of the Japanese and Chinese names, transliteration of foreign words, and filing system. What is more, so flexible and hospitable a notation system should be adopted as to meet the anticipated changes. The writer introduces an author notation system that could make 150,000 divisions by combinating figures, thus making it possible to endure changes through readjustments. It is considered effective, convenient, and efficacious for individualization.

• The KIPS Transactions:PartB
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• v.12B no.4 s.100
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• pp.507-512
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• 2005

There is a limitation of using a small number of input buttons for writing Hangul words on hand-held devices. As a quick and convenient way of implementing Hangul vowels by small number of buttons, we propose a vowel input system in which vowels are fabricated from eight vowels. Our input system supports a fast input speed by making all the diphthong from one or two strokes. It also adopts a multiple input method for diphthong that users can make a diphthong in a user-friendly way of vowel writing formation or pronunciation similarity. Furthermore, we added an error correction functionality for the similar vowels that are caused by vowel harmony rules. When the proposed method is compared to the previous ones, our method outperformed in the input speed and error correction.