• 음성과학
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• 제7권4호
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• pp.3-10
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• 2000

This paper presents a time-based Pitch Determination Algorithm (PDA) for the reliable estimation of Pitch Period (PP) in speech signals. Based on the Dyadic Wavelet Transform (DyWT) , the proposed PDA detects the presence of Glottal Closure Instants (GCI) and uses the information to determine the pitch period. We also examine the problem of conventional PDAs based on DyWT; their performance is compared with the proposition of this paper. The effectiveness of the proposed method is tested with real speech signals containing a transition between the voiced and the unvoiced interval where the energy of the voiced signal is unsteady. The result shows that the proposed method provides good performance in estimating both the unsteady GCI positions as well as the steady parts.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2000년도 학술발표대회 논문집 제19권 2호
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• pp.197-200
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• 2000

This paper presents a time-based Pitch Determination Algorithm (PDA) for reliable estimation of pitch Period (PP) in speech signal. In proposed method, we use the Dyadic Wavelet Transform (DyWT), which detects the presence of Glottal Closure Instants (GCI) and uses the information to determine the pitch period. And, the proposed method also uses the periodicity property of DyWT to detect unsteady GCI. To evaluate the performance of the proposed methods, that of other PDAs based on DyWT are compared with what this paper proposed. The effectiveness of the proposed method is tested with real speech signals containing a transition between voiced and the unvoiced interval where the energy of voiced signal is unsteady. The result shows that the proposed method provides a good performance in estimating the both the unsteady GCI positions as well as the steady parts.

• 수완나부미
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• 제14권1호
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• pp.193-228
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• 2022

This study investigates the production and perception of Vietnamese tones by Japanese, Lao, and Taiwanese second language (L2) learners [n=30], comparing their performance in an Imitation task to that of Identification and Read-Aloud tasks. The results show that the Imitation task is generally easier for L2 speakers than the Identification and Read-Aloud tasks, suggesting that imitation is performed without some of the skills required by the other two tasks. It is also found that Lao and Taiwanese speakers outperform Japanese speakers, suggesting that prior experience with one tone language facilitates the acquisition of tone in another language. The result on speakers' tonal range show that L2 leaners have significantly narrower tonal F0 range than control Vietnamese speakers [n=11]. The results of error pattern analysis and tonal transcription also suggest that non-modal voice (glottal stop and creakiness) and contour tones (bidirectional fall-rise) are more difficult for L2 learners than modal voice tones (e.g., unidirectional contours: rising, falling, and level).

• 대한후두음성언어의학회지
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• 제17권2호
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• pp.98-102
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• 2006

Background and Objectives : Voice onset time(VOT) is defined as the time interval from oral release of a stop consonant to the onset of glottal pulsing in the following vowel. VOT is a temporal characteristics of stop consonants that reflects the complex timing of glottal articulation relative to supraglottal articulation. Stop consonants are characterized by creation of a pressure difference across a complete occlusion in the vocal tract, followed by a sudden release 'burst' due to opening that occlusion. The objects of this study is to evaluate a usefulness of voice onset time in the assessment of voice disorderd patients. Subjects : Subjects were 20 adults with normal voice and with benign laryngeal disorders. Subjects with voice disorders represented the following vocal pathologies : vocal polyp, vocal nodule, Reinke's edema and unilateral vocal fold paralysis(UVFP). Control subjects were matched for age (21-40 yews old) and sex(male) with the voice disorders subjects and had normal vocal qualities with no history of voice disorders. Methods : Each voice-disordered and matched control subject read the test passages containing three types of Korean bilabial consonants. VOT measures were made for the initial $/p/p^h/\;and\;/p'/$. VOT was measured using acoustic waveform or wide band spectrogram. Results : For each voiceless stop consonants, there was a significant difference in VOT between the voice disordered and normal subjects. The mean VOTs of the lax stops in UVFP was significantly shorter than those of control subjects in the UVFP. The mean VOTs of the aspirated stops in the vocal polyp and nodule were longer than those of control subjects, but not significant. The mean VOTs of the glottalized in voice disordered groups were longer than those of control subjects, and significant statistically in the UVFP. Conclusions : VOT may be a clinically useful acoustic parameter in the assessment of voice disordered patients, especially in the unilateral vocal fold paralysis.

• 대한후두음성언어의학회지
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• 제17권2호
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• pp.107-110
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• 2006

Background and Objeetives : There are few studies reported that specifically examined the voice onset time(VOT) in patients with bilateral vocal nodules. The purpose of this study was to study the characteristics of voice onset in patients with bilateral vocal nodules. Materials and Methods : 52 female patients with bilateral vocal nodules were examined, aged from 20 to 54 years, and were compared with 25 normal female control group. All subjects produced five repetitions of the voiceless stops $/p^h,\;t^h\;k^h/$ in vowel context /ai_a/. VOT was measured by the time between the release of the stops and the onset of voicing. Results : VOTs of the voiceless stops $/p^h/\;and\;/t^h/$ in patients with bilateral vocal nodules were significantly shorter than those of normal subjects. VOT of the $/k^h/$ in them was shorter than those of normals, but the difference was not significant. This results showed that VOTs of the voiceless stops in patients with bilateral vocal nodules were shorter than those of normal subjects. Conclusion : The rapid onset of voicing in patients with bilateral vocal nodules might be associated with increased laryngeal muscle tension by hard glottal attacks. We suggest that VOT can be a clinically useful acoustic parameter for evaluating voice in patients with bilateral vocal nodules.

• 대한후두음성언어의학회지
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• 제30권2호
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• pp.82-86
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• 2019

In the field of otolaryngology-head and neck surgery, botulinum toxins are widely used for the treatment of spasmodic dysphonia and vocal tremors. Recently, the applications of botulinum toxin have gradually expanded with time, to include vocal fold granuloma, mutational falsetto, bilateral vocal cord paralysis, and chemical reduction for arytenoid dislocation as an adjunctive modality. According to a nation-wide multicenter study conducted by the Korean Society of Laryngology, Phoniatrics and Logopedics for treatment modality of contact granuloma, among the various treatment modalities, botulinum toxin injection showed the highest response rate and lowest recurrence rate in both primary and refractory cases. Therefore, botulinum toxin could be reserved as a second-line treatment for contact granuloma in which the first treatment was not effective, but also could be used as a first-line treatment depending on the patient's and institution's situation. For recalcitrant nodules, injection of botulinum toxin into the bilateral thyroarytenoid muscle will reduce glottal contact force and result in a forceful chemical voice rest. In special situations, botulinum toxin injection could be one of the alternative treatment options for recalcitrant vocal nodules.

• 말소리와 음성과학
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• 제3권2호
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• pp.99-105
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• 2011

The treatment for patients with mutational dysphonia typically is useful with vegetative phonation, but has not yet been studied. This study attempts to identify the effect of $SKTCLP^{(R)}$ using throat clearing and laughing in patients with mutational dysphonia. The study, which was designed by the author, included 26 patients aged from 14 to 32 years (mean: 18.7 years) who had been diagnosed with mutational dysphonia between January 2007 and June 2010. Voice therapy for these patients included $SKTCLP^{(R)}$, ranging from two to seven sessions (mean: 3.8 sessions). Results were evaluated by videostroboscopy, perceptual evaluation of GRBAS scale, aerodynamic test, and acoustic analysis before and after therapy. Most patients could phonate with low pitch from the beginning and sustain with normal pitch sound in the last session. We had found that glottic gap reduced after therapy and anterior-posterior compression of superior laryngeal part at the first time, and these patients had complete closure of the glottis after treatment. The results of acoustic and aerodynamic measures after treatment indicated significant decreases in Fo, Jitter, Shimmer, SFF, and SPI, and increases in MPT, Psub, and vocal efficiency (p<.05). $SKTCLP^{(R)}$ may be a useful treatment method in managing mutational dysphonia. We can suggest this technique may be useful in improving the voice quality of other functional dysphonia having glottal chink or functional aphonia.

• Archives of Plastic Surgery
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• 제38권6호
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• pp.867-870
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• 2011

Purpose: The authors would like to introduce two patients who presented with velopharyngeal inadequacy. We emphasize the importance of nasaopharyngeal endoscopy in evaluating the velopharyngeal function and the usefulness of biofeedback trial therapy. Methods: Two patients visited our clinic due to velopharyngeal inadequacy. Both of the patients showed hypernasality, nasal emission and compensatory articulation such as glottal stop. During oral examination and nasopharyngeal endoscopy both showed no evidence of structural deformities. One inconsistently showed a small gap during articulation. The other showed a rather large gap during compensatory articulation. Both received a simultaneous biofeedback trial therapy using the nasopharyngeal endoscope. Results: Both patients were successfully diagnosed and treated at once using biofeedback trial therapy with nasopharyngeal endoscopy. By giving direct visual feedback to the patient, they were both able to achieve complete velopharyngeal closure during production of 2~3 nonsence syllables and hypernasality was not detected in both of them. Conclusion: The authors were able to help patients with velopharyngeal inadequacy to have velopharyngeal closure through biofeedback trial therapy. The accurate evaluation of velopharyngeal function and the possibility of closure prevented unnecessary operations.

• 한국음향학회지
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• 제16권3호
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• pp.18-25
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• 1997

본 연구에서는 성문파에 의한 음원 특성과 입술에서 음성이 방사될 때 발생하는 방사 특성을 효과적으로 제거하기 위하여 성문파의 음원 특성과 입술에서의 방사 특성은 근사적으로 음파의 에너지와 비례한다고 가정하고, 정규화된 단구간 에너지를 이용하는 에너지 의존 프리엠퍼시스 기법을 제안하며, 이를 이용하여 비안정 구간인 발음의 시작 부분과 천이구간에 대하여 음성 신호 분석 성능을 개선하고자 한다. 제안된 프리엠퍼시스 기법을 이용하여 5개 한국어 단모음의 스펙트럼 및 형성음 주파수 추출 등의 음성 신호 분석을 수행하고, 기존에 널리 이용되던 두 가지 프리엠퍼시스 기법과 성능을 비교하여 본 결과, 제안된 방법에 의한 스펙트럼의 형태가 기존의 방법에 비하여 상당히 개선되었고, 보다 더 정확한 형성음 주파수를 나타내며, 인접한 두 형성음 주파수가 증첩되는 현상이 제거되었음을 알 수 있었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.313-315
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• 1997

We developed a new analysis technique for the assessment of irregular vibratory movement of vocal folds. Successive frames of pre-recorded video images from videostroboscopy were transferred to computer memory and a vibratory tract of one selected point was described as a waveform by displaying the same lines of all frames along the y-direction. By applying this technique, irregular vibratory patterns of multiple regions, such as asynchronized registration of glottal cycles, could be easily visualized. It would be possible to monitor and analyze the pathologic changes of vocal fold movement by means of this newly developed system.