• 음성과학
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• 제2권
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• pp.9-23
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• 1997

Through iterative analysis and synthesis experiments on Korean monosyllables, the Korean text-to-speech system was implemented using the phoneme-based formant synthesis method. Since the formants of initial and final consonants in this system showed many variations depending on the medial vowels, the database for each phoneme was made up of formants depending on the medial vowels as well as duration information of transition region. These techniques were needed to improve the intelligibility of synthetic speech. This paper investigates also methods of concatenating the synthesis units to improve the quality of synthetic speech.

• 음성과학
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• 제8권1호
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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.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.971-976
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• 1994

A speech display system is developed for the evaluation and the training of speech utterance. The speech is analyzed by linear predictive technique every 5 ms and the frequencies of the lowest two spectral local peaks P1 and P2 are extracted. The vowel trakectory is displayed using those frequencies on th P1-P2 plane. In most cases, P1 and P2 correspond to the first and the second formants, but in the case of indistinct utterance, the correspondence between the local spectral peaks and the formants tends to fall into disorder. And the system is considered to be useful for the evaluation of speech quality. The examples of some words uttered by normal speakers and some patients with difficulty in utterance are compared each other for the discussion of the effectiveness of the system.

• 대한전자공학회논문지
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• 제25권12호
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• pp.1503-1512
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• 1988

As the basic analysis to solve the within-and cross-speaker variability in phoneme based speech recognition, changes in pitch and formant frequencies of 8 Korean vowels with age and sex of speaker has been investigated by analyzing a large number fo samples. Conclusions obtained are as follows: 1) Changes in pitch frequency with age and sex of speaker for children are hard to distinguish and the difference of before and after the voice change is analyzed approximately 0.2 oct. for female an 0.9 oct. for male. 2) While most of the formants of vowel considerably change with the age of speaker, the change becomes smaller as the age becomes older. 3) While there is an indirect correlation between pitch and formant with change in age, it is hard to see a direct correlation. 4) When the objects of the recognition experiment by pitch and formants are various speakers in each age and sex, pitch also works as an efficient recognition parameter.

• 말소리와 음성과학
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• 제2권4호
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• pp.11-18
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• 2010

This study compared classical operatic singing and applied music singing using the vocal assessment software, Dr. Speech and SPEAD from Lx Speech Studio. Participants in this study included: eight female operatic singers (mean 22.6 yrs, average career 7.5 yrs); eight male operatic singers (mean 25.6 yrs, average career 7.3 yrs); eight female applied music singers (mean 25.1 yrs, average career 6.1 yrs); and eight male applied music singers (mean 27.6 yrs, average career 6.8 yrs). The results demonstrated significantly higher closed quotient values in female applied music singers during singing (p<.05). In addition, higher closed quotient values in speaking were presented in male classical singers and longer MPT was obtained in female operatic singers (p<.05). Furthermore, singer's formants were identified in all male operatic singers and in three female operatic singers. In contrast, only one applied music male and one female singer showed singer's formants while singing.

• The Journal of the Acoustical Society of Korea
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• 제18권2E호
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• pp.31-38
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• 1999

This paper focuses on extracting formants from transfer function, derived from linear prediction analysis of speech signal. The second derivative of the log magnitude spectrum of the transfer function, the first and third derivatives of the phase spectrum of the transfer function in the z-plane are discussed. Their resolutions of detecting formants are analyzed and some comparisons are given. Theoretical analyses and experimental results show that the third derivative of the phase spectrum decays more rapidly around the formant locations than the first derivative of the phase spectrum and the second derivative of the log magnitude spectrum. Compared with the second derivative of the log spectrum and the first derivative of the phase spectrum, the third derivative of the phase spectrum has higher resolution in frequency domain and provides more accurate formant extraction.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2005년도 추계 학술대회 발표논문집
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• pp.97-100
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• 2005

The aim of the present study is to compare the vowel formants between generations in Daegu dialect. 20 Daegu dialect speakers were participated in this study; 10 were in their 40's, the other 10were in their 20's. As a result, the distance of /ㅣ/ and /ㅐ/, and, /ㅡ/ and /ㅓ/ in 20's is further than 40's, while the distance of /ㅗ/ and in 20's is closer than 40's. It seems reasonable to conclude that vowels in Daegu dialect change to have their own stable space, but /ㅗ/ and /ㅜ/ does not.

• 대한후두음성언어의학회지
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• 제16권1호
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• pp.10-14
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• 2005

Background and Objectives : Vowels are characterized on the basis of formant patterns. The first formant(F1) is determined by high-low placement of the tongue, and the second formant (F2) by front-back placement of the tongue. The fundamental frequency(F0) of a soprano often exceed the normal frequency of the first formant. And the vocal intensity is boosted when F0 is high and a harmonic coincides with a formant. This is called a formant tuning. Experienced singers thus learned how to tune their formants over a resonable range by lowering the tongue to maximize their vocal intensity. So, the current study aimed to identify the formant tuning in one experienced soprano by comparing the first formants of vowel [i] in three different voice production : speech, ascending scale, and vocalize. Materials and Method : All voices recordings of vowel [i] in speech, ascending scale (from F4 note to A4 note), and vocalize(:Ridente la calam") were made with digital audio tape-corder in a sound treated room. And the captured data were analyzed by the long term average(LTA) power spectrum using the FFT algorithm of the Computerized Speech Lab(CSL, Kay elementrics, Model, 4300B). Results : Although the first formant of vowel [i] in speech was 238Hz, those of ascending scale [i] were 377Hz, 405Hz, 453Hz respectively in F4(349z), G4(392Hz), A4(440Hz) note, and 722Hz, 820Hz, 918Hz respectively in F5 (698Hz), G5(784Hz), A5(880Hz) note. In vocalize, first formants of [i] were 380Hz, 398Hz, 453Hz respectively in F4, G4, A4 note, and 720Hz, 821Hz, 890Hz respectively in F5, G5, A5 note. Conclusion : These results showed that the first formant of ascending scale and vocalize sustained higher frequency than fundamental frequency in high pitch. This finding implicates that the formant tuning of vowel [i] in ascending scale was also noted in vocalize.

• 말소리와 음성과학
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• 제11권4호
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• pp.97-108
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• 2019

한국인 성인을 대상으로 최적의 포먼트 분석이 가능하도록 자동화된 프랏 스크립트를 구현하였다. 최적의 포먼트 분석이란 프랏에서 포먼트 분석 시 설정하는 2가지 세팅 파라미터(최대 포먼트, 포먼트 개수)를 조합하여 측정된 제1, 제2 포먼트의 편차합이 최소일 때를 가리킨다. 포먼트 분석의 신뢰성을 높이기 위해서는 성별이나 모음의 종류에 따라 LPC 차수를 다르게 설정해야 하는데 프랏 매뉴얼에서는 최대 포먼트 설정 값으로 남성 5,000 Hz, 여성 5,500 Hz, 측정개수는 5개를 권고한다. 그러나 이렇게 권고된 포먼트 세팅 설정이 한국어 모음에 대해서도 타당한지 검증이 필요하다. 본 연구에서 구현한 4가지 스크립트를 적용한 결과, 각 모음별 포먼트 산점도로 확인하였을 때 특히 여성의 경우 스크립트에 따라 측정된 포먼트 변이의 폭이 두드러지는 차이를 보였다. 포먼트 산점도와 통계 결과를 통해 linear_script와 qtone_script가 포먼트 측정에서 더 신뢰성이 높은 것을 알 수 있었다. Linear_script, qtone_script에서 최적의 세팅으로 설정된 최대 포먼트와 포먼트 개수의 데이터 경향성을 살펴보면, 전설 모음 [이, 에]의 경우 권고 설정보다 최대 포먼트 값은 높게, 포먼트 개수의 값은 적게 설정되었다. 반면 후설모음 [오, 우]의 경우, 권고 설정보다 최대 포먼트 값은 낮게, 포먼트 개수의 값은 많게 설정되는 것을 확인할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1042-1045
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• 2003

In this paper, we propose the speaker identification system that uses vowel that has speaker's characteristic. System is divided to speech feature extraction part and speaker identification part. Speech feature extraction part extracts speaker's feature. Voiced speech has the characteristic that divides speakers. For vowel extraction, formants are used in voiced speech through frequency analysis. Vowel-a that different formants is extracted in text. Pitch, formant, intensity, log area ratio, LP coefficients, cepstral coefficients are used by method to draw characteristic. The cpestral coefficients that show the best performance in speaker identification among several methods are used. Speaker identification part distinguishes speaker using Neural Network. 12 order cepstral coefficients are used learning input data. Neural Network's structure is MLP and learning algorithm is BP (Backpropagation). Hidden nodes and output nodes are incremented. The nodes in the incremental learning neural network are interconnected via weighted links and each node in a layer is generally connected to each node in the succeeding layer leaving the output node to provide output for the network. Though the vowel extract and incremental learning, the proposed system uses low learning data and reduces learning time and improves identification rate.