• 대한음성학회지:말소리
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• 제56호
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• pp.159-172
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• 2005

This paper analyzes the vocal tract area estimation algorithm used as a part of a speech analysis program to help deaf children correct their pronunciations by comparing their vocal tract shape with normal children's. Assuming that a vocal tract is a concatenation of cylinder tubes with a different cross section, we compute the relative vocal tract area of each tube using the reflection coefficients obtained from linear predictive coding. Then, we obtain the absolute vocal tract area by computing the height of lip opening with a formula modified for children's speech. Using the speech data for five Korean vowels (/a/, /e/, /i/, /o/, and /u/), we investigate the effects of the sampling frequency, frame size, and model order on the estimated vocal tract shape. We compare the vocal tract shapes obtained from deaf and normal children's speech.

• 전기학회논문지
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• 제59권6호
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• pp.1126-1130
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• 2010

Speech production can be viewed as a filtering operation in which a sound source excites a vocal tract filter. The vocal tract is modeled as a chain of cylinders of varying cross-sectional area in linear prediction acoustic tube modeling. In this modeling the most common implementation assumes equal length of tube sections. Therefore, to model complex vocal tract shapes, a large number of tube sections are needed. This paper proposes a new vocal tract model with unfixed sectionlengths, which uses the reduced lattice filter for modeling the vocal tract. This model transforms the lattice filter to reduced structure and the Burg algorithm to modified version. When the conventional and the proposed models are implemented with the same order of linear prediction analysis, the proposed model can produce more accurate results than the conventional one. To implement a system within similar accuracy level, it may be possible to reduce the stages of the lattice filter structure. The proposed model produces the more similar vocal tract shape than the conventional one.

• 대한의용생체공학회:의공학회지
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• 제13권4호
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• pp.275-284
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• 1992

Development of Integrated Speech Training Aids for Hearing Impaired In this study, a spepch lralnlng aids that can do real-time display of vocal tract shape and other speech parameters together in a single system is implemenLed and self-training program for this system is developed. To estimate vocal tract shape, speech production process is assumed to be AR model. Through LPC analysis, vocal tract shape, intensity, and log spcclrum are calculated. And, fundamental frequency and nasality are measured using vibration sensors.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2005년도 추계 학술대회 발표논문집
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• pp.51-54
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• 2005

This paper analyzes the vocal tract area estimation algorithm used as a part of a speech analysis program to help deaf children correct their pronunciations by comparing their vocal tract shape with normal children's. Assuming that a vocal tract is a concatenation of cylinder tubes with a different cross section, we compute the relative vocal tract area of each tube using the reflection coefficients obtained from linear predictive coding. Then, obtain the absolute vocal tract area by computing the height of lip opening with a formula modified for children's speech. Using the speech data for five Korean vowels (/a/, /e/, /i/, /o/, and /u/), we investigate the effects of the sampling frequency, frame size, and model order. We compare vocal tract shapes obtained from deaf and normal children's speech.

• 음성과학
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• 제3권
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• pp.83-92
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• 1998

Vowels are classified by vocal tract shapes. These shapes form constriction points along the tract, which have an influence on such vocal tract resonance as $F_l,\;F_2,\;F_3$, and so on. This study reviews the perturbation theory of the tract and determines the corresponding formant frequencies from modified vocal tracts using vocal tract area function. Then, formant variation is observed from the theory. Finally, each set of $F_l,\;F_2,\;and\;F_3$ frequency is input to a speech synthesis software to make a vowel sound. Auditory impression of each sound without any modification of its vocal tract shape is almost the same as the corresponding phonetic symbol. Formant frequencies of $F_l,\;F_2,\;F_3$ vary according to the perturbation theory. Generally, constriction along the node causes formant values to decrease while constriction along the anti-node cause it to increase. Vocal tracts modified by more than $3\;cm^2$ change vowel qualities of /a/ and /i/ into those of f /v/ and /$\varepsilon$/, respectively. This study will be helpful in simulating sounds from modified vocal tracts before any operation. Further studies are desirable to compare vocal tract shapes of various languages and their sounds together.

• 대한방사선기술학회지:방사선기술과학
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• 제20권1호
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• pp.21-27
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• 1997

Total laryngectomy has become an usual treatment for any advanced carcinoma of the laynx, but most patients who have undergone total laryngectomy have shown permanant disability in voice production. I compared the first three formant frequencies estimated from MRI to those measured directly from speech data of the T-E patients and the normal. It was to estimate the accuracy of MRI and to compare the vocal tract shape of the normal to T-E patients. The obtained results were as follows : 1. The middle sagittle section of the MRI represents vocal tract well during pnonation. The vocal tract shape of the T-E shunt patients are lack of pharyngeal space and superior space of the glottis. 2. The length of the normal subject's vocal tract is 17 cm. For the T-E shunt patients, the length from lip to shunt opening is 17.5 cm in case 1, and 18.5 cm in case 2. That of the true resonante chamber is 13 cm and 13.5 cm for each case respectively. 3. T-E shunt patients phonated strained voice. The intensity of the higher formant frequency decreased especially in /o/, /u/. 4. The vocal tract is shortened during the phonation by T-E shunt patients. In case of /e/ and /i/, front cavities are constricted while back cavities are shortened. 5. The pseudoglottis of the T-E shunt patients is located at $14{\sim}15\;cm$ below from lips.

• 한국산학기술학회논문지
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• 제10권8호
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• pp.2110-2116
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• 2009

문화 산업은 보건, 의료 산업과 함께 삶의 혜택을 누릴 수 있는 기회를 제공해 주는 분야라고 할 수 있을 정도로 현대 사회에서 많은 관심을 받고 있다. 특히, 대중적 지지 기반을 보유하고 있는 음악 산업은 대중성과 독창성이 함께 공존하여 감정을 표출하고 쉽게 접근할 수 있는 예술적 가치로 인정받고 있다. 본 논문에서는 이러한 음악산업에서 핵심적인 부분이라 할 수 있는 가수의 음악적 재능을 평가하는 지표를 설계하고자 한다. 이를 위해 동일한 음악에 대한 가수의 목소리와 일반인의 목소리에서 성도의 모양 변화에 대한 분석을 수행하기 위해 스펙트로그램 분석 요소를 적용하였으며 결과 파형의 패턴 분석을 실험하여 두 집단간의 비교, 분석을 수행하였다. 따라서 실험에 사용될 대중적 음악을 선정하고 동일 부분에 대한 가수와 일반인의 목소리를 수집하여 시간의 흐름에 따른 성도 모양의 변화를 패턴 분석하고 이를 비교, 분석하여 음악성을 평가할 수 있는 지표를 설계하였다.

• 음성과학
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• 제7권4호
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• pp.59-72
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• 2000

Vocal tract resonances are of paramount importance to voice sounds. Resonance frequencies determine vowel quality and the personal voice timber. The aim of this study was to make an effective diction program according to tuning formant frequencies by adjusting the vocal tract shape in professional voice users. Twelve male student singers and eleven female student singers participated in this study. The subjects repeated five simple vowels /a, e, i, o, u/ in normal speech and singing. The spoken vowels and sung vowels were measured by formant frequencies and the singer's formant frequencies using CSL and DSP Sona-Graph. Separately, Plot formants program was used to draw the vowel chart. The results were as follows. (1) Total formant frequencies of female singers were 11% higher than those of males singers in singing. (2) The F1 and F3 of sung vowels increased compared to F1 and F3 spoken vowels. However, The F2 of sung vowels decreased in comparison with F2 of spoken vowels. (3) Posterior vowel /u/ were moved anteriorly. This phenomenon seemed to be due to head voice singing training. (4) Singer's formant frequencies in student singers appeared according to the part: 2560 Hz for baritone, 2760 Hz for Tenor, 2821 Hz for Mezzo soprano and 3420 Hz for soprano.

• 말소리와 음성과학
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• 제10권1호
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• pp.57-64
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• 2018

The purpose of the present study was to explore the radiological and acoustic characteristics of "Arae-a" (/${\cdot}$/) articulation in two male Jeju language speakers, focusing on selected measures in radiological images derived from computed tomography scans, as well as the first and the second formant measures in selected vowels. An elderly male speaker (a 78-year-old) and a young male speaker (a 34-year-old) participated in the study. During the production of four selected vowels, the shape of the vocal tract was identified, and selected measures were obtained from the elderly participant's computed tomography (CT) scans. For acoustic analysis, the participants were given a list of near-minimal pairs consisting of 112 words and asked to read them aloud. The results indicated that the "Arae-a" (/${\cdot}$/) articulation of the elderly speaker showed unique acoustic and radiological characteristics compared to other similar vowels, thus presenting substantial consistency with the descriptions of the "Hunminjeongeum Haeryebon." In contrast, the F1 and F2 measures of the young male's /${\cdot}$/ articulation were not distinguished from those of /ㅗ/. Current results, in part, support the scientific principles underlying the invention of "Arae-a," which reflects the shape of the vocal tract during production, and the necessity for further research.

• 대한후두음성언어의학회지
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• 제33권2호
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• pp.83-88
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• 2022

Hunminjeongeum had 17 initial consonant letters. Among them, five consonant letters, those are ㄱ (牙音, molar sound letter), ㄴ (舌音, lingual sound letter), ㅁ(脣音, labial sound letter), ㅅ (齒音, dental sound letter), ㅇ (喉音, guttural sound letter), were served as chief consonants. There was no argument that consonant letters were made by symbolizing the shape of vocal organs during phonation of them. It could be phoniatrically explained that all of five chief consonants were morphologically symbolized from left lateral view of vocal tract during articulation. Although 'ㄱ' was known as molar sound, it was not modeled the shape of molar tooth but modeled the shape of tongue at molar teeth bearing area. The same principle applies to 'ㅅ', and it was represented the shape of upper surface of anterior tongue instead of incisor teeth. 'ㄴ' was a lingual sound and directly shaped the shape of tongue. 'ㄷ' was made by addition of a stroke 'ㅡ' meaning hard palate above 'ㄴ'. 'ㅁ' was represented the shape of lateral view of anterior mouth. 'ㅇ' was looked like shaping left lateral view of laryngopharyngeal space.