• 대한전기학회논문지
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• 제41권2호
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• pp.209-216
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• 1992

Deafs train articulation by observing mouth of a tutor, sensing tactually the motions of the vocal organs, or using speech training aids. Present speech training aids for deafs can measure only single speech parameter, or display only frequency spectra in histogram of pseudo-color. In this study, a speech training aids that can display subject's articulation in the form of a cross section of the vocal organs and other speech parameters together in a single system is to be developed and this system makes a subject know where to correct. For our objective, first, speech production mechanism is assumed to be AR model in order to estimate articulatory motions of the vocal organs from speech signal. Next, a vocal tract profile model using LP analysis is made up. And using this model, articulatory motions for Korean vowels are estimated and displayed in the vocal tract profile graphics.

• 음성과학
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• 제7권1호
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• pp.89-96
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• 2000

Examination of the vibrations of the vocal fold is very important in patients with voice changes. The newly developed videokymography (VKG) takes images in real time and records irregular vibrations of the vocal fold. However, there are few data on VKG findings. We studied VKG to evaluate the vibratory characteristics of the vocal fold in benign vocal fold lesions. Unique vibratory patterns, blurred demarcation of the mucosal propagation, decreased margin amplitudes, asymmetry in phase or amplitude, and a level difference of the contact site were observed in each benign vocal-fold lesion. We conclude that each type of laryngeal lesion has specific characteristic which are revealed by VKG examination, these parameters can be quantified and used to objectively evaluate VKG findings. Based on these results, VKG can be used as a supplementary diagnostic tool.

• 대한후두음성언어의학회지
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• 제14권2호
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• pp.94-97
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• 2003

Background and Objectives : Bowing of the vocal fold, a bowed edge of the vocal fold results from various disorder causes glottic incompetence resulting in voice disorders. The results of treatment were not satisfactory even though a variety of methods of treatment were applied. The goal of this study is to evaluate of efficacy of the non-surgical, voice therapy in patients with vocal fold bowing. Materials and Method : Twenty two patients of vocal fold bowing not resulting from vocal fold palsy and sulcus vocalis were analyzed. After voice therapy and medical treatment, parameters of perceptual, acoustic, aerodynamic analysis and stroboscopic findings were compared those of pretreatment results. Results and Conclusion : Jitter, shimmer and maximal phonation time were significantly improved and subjective satisfaction was improved in 73% of patients. In the videostroboscopic examination, vocal fold gap was decreased in 27% of patents. The result of this study indicates that voice therapy alone has effect in treatment of vocal fold bowing. Voice therapy is one of the mainstay of treatment of vocal fold bowing.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.21-24
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• 2008

The present study numerically investigates the glottal airflow characteristics as well as acoustic features of phonation fully coupled with dynamic behavior of vocal folds. The vocal folds are described by a low-dimensional body-covered model characterized by bio-mechanical parameters such as glottal width, vocal folds stiffness, and subglottal pressure. The flow in the vocal tract is modeled as an incompressible, axisymmetric form of the Navier-Stokes equations (INS), while the acoustic field is predicted by the linearized perturbed compressible equations (LPCE). The computed result shows that a two-mass model of vocal folds is sufficient to reproduce temporal variations in oral airflow and glottis motion produced by female speakers. It is also found that i) the glottal width has a significant effect on the amplitude of glottal flow, and thus on the amplitude of acoustic wave in the vocal tract, ii) the vocal fold tension is the main control parameter for the fundamental frequency of phonation, iii) the subglottal pressure plays an appreciable role on reproduction of the self-sustained oscillation of vocal folds, and iv) the strength of pulsating airflow and vortical structures are primarily affected by glottal width and subglottal pressure, and are closely related to pitch, loudness, and voice quality. Finally, more comprehensive explanation about the difference between one- and two-mass models is presented with discussion of effectiveness of vocal folds oscillation and voice quality.

• 대한후두음성언어의학회지
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• 제9권1호
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• pp.71-78
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• 1998

Type Ⅰ thyuroplasty in conjunction with arytenoid adduction is one of the excellent techniques in the treatment of unilateral vocal fold paralysis. But perioperative objective evaluation of the patients is difficult. With the development of the videostroboscopy and image analysis program, we could quantify the Glottal Area Waveform(GAW) in patients with unilateral vocal fold paralysis and investigated the relationship between the glottal area and aerodynamic and acoustic parameters. Eight female patients who were performed type Ⅰ thyroplasty in conjunction with arytenoid adduction and 5 females with normal vocal function were involved in this study. Preoperative and postoperative videostroboscopy and vocal function study wire performed. GAW was analysed quantitatively with image analysis program (Kay Stroboscope Image analysis, KSIP) Peak Glottal Area(PGA), Baseline Offset(BO), and Closing Phase(CP) were increased in patients with unilateral vocal fold paralysis and they were reduced after the operation. Mean flow Rate (MFR) was well correlated with the PGA in normal control group and unilateral vocal fold paralysis patients. Noise to harmonic ratio(NHR) was correlated with PGA only in preoperative unilateral vocal fold paralysis patients. In conclusion quantitative measurement of the GAW is useful method in evaluation of unilateral vocal f31d paralysis patients.

• 대한전자공학회논문지
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• 제19권1호
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• pp.1-8
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• 1982

적응선형자측(adaptive linear prediction) 방법에 의한 음성신묵의 parametric representation에 대한 연구는 이제까지 널리 행해져 왔다. 본 논문에서는 LPC(Linear Predictive Coding) 방법으로 한글 격모음및 일체 복함모음에 대한 parameter들을 각각 분석해 내어서 이를 이용하여 한글모음 상호간의 근사도(affinity)에 대한 통계적 연구를 하여 음성학적인 면과 비교 고찰하였다. 그리고 그에 따른 결과로서 음성학적으로 근사하여 혼동되는 경향이 있는 모음간에는 vocal tract의 dynamic parameter 간에도 근사성이 있음을 밝혔다.

• 대한후두음성언어의학회지
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• 제11권1호
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• pp.12-19
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• 2000

Background and Objectives : Dysphonia may be secondary to many different type of benign vocal cord lesions such as vocal polyp, vocal nodule, Reinke's edema, and intracordal cyst. Diagnosis and treatment of intracordal cysts are more difficult than other benign vocal cord lesions. But postoperative voice analysis of intracordal cyst have rarely been reported in the literature. The purpose of this study is to analyze aerodynamic and acoustic results and videostroboscopic findings before and after laryngomicrosurgery. Materials and Methods : We reviewed the pre and post-operative voice analysis results and videostroboscopic findings of 15 surgically treated patients of intracordal cysts at Severance hospital from Jun. 1997 to Nov. 1999 retrospectively. They were diagnosed with videostroboscopic findings, surgical findings, and pathologic reports. Their pre and post-operative speech were analyzed with MDVP(Multi Dimension Voice Analysis Program) of CSL(Computerized Speech Lab) and Aerophone II. Their pre and post-operative mucosal wave of true vocal cord was analyzed with videostroboscopy. In order to compare this results with normal group, 10 of normal persons were evaluated with same methods. Results : After the operation, mucosal wave of true vocal cord was improved in all patients. Postoperative acoustic and aerodynamic results were improved in almost parameters, but they did not reach the normal value. Conclusions : Videostroboscopy was essential in diagnosing intracordal cysts. By comparing the acoustic and aerodynamic results and video-stroboscopic findings before and after the laryngomicrosurgery, postoperative vocal function was defined more accurately and objectively. Almost parameters may be useful in assessing the quantitative changes in vocal quality before and after the laryngomicrosurgery.

• 한국음향학회지
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• 제14권5호
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• pp.94-101
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• 1995

본 논문에서는 쉰 목소리 메커니즘 분석을 위한 4질량 성대 모델을 제안하였다. 쉰 목소리가 성대의 병리학적 변화에 기인한다는 것과 성문 파형이 성대의 움직임 상태를 반영한다는 사실에서, 병든 성대를 비대칭 구조이고 4질량형으로 가정하였다. 정상 목소리와 쉰 목소리에 대한 모델 변수들과 성문 파형을 분석하여 모델 변수와 병리학 사이의 관계를 검토하였다. 실험 결과 쉰 목소리의 음향 특징과 병리학간의 관계를 밝힐 수 있었고 후두 질병 진단과 쉰 목소리의 음질 향상에도 본 논문에서 제안한 방법이 사용될 수 있음을 알았다.

• 대한후두음성언어의학회지
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• 제12권1호
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• pp.11-16
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• 2001

Background and Objectives : A burn injury to the glottis differs from a burn injury to the trachea, bronchi, and lung parenchyma, in that thermal injury does not occur to any significant degree below the level of the larynx, due to the effective cooling of air by the upper airway and to reflex closure of the vocal cords from a blast of hot air. Therefore, the laryngeal inhalation injury give rise to airway problem and voice change. The objectives of this study is to assess management of laryngeal inhalation injury and voice change after management. Materials and Methods : Voice choses and laryngeal injuries of eight laryngeal inhalation patients were analyzed through questionnaire, voice dynamic laboratory, and laryngeal stroboscopy. Operative management was performed to five patients for airway patiency and vocal cord movement on laryngeal pathology ind voice therapy was performed to all patients. One-year after, voice changes and laryngeal injuries were reanalyzed with same methods. Results : Vocal breathiness, decreased voice intensity, reduced voice range, and easy fatigability were major complaints of laryngeal inhalation patients. Glottic stenosis were developed to five of eight patients, and vocal cord atrophy, bowing were developed to others. Vocal cord mucosal waves were significantly decreased in all patients. Jitter(%), Shimmer(dB) were increased and Maximal phonation time(MPT) was decreased. One-year after, subjective voice changes and objective voice parameters were improved. And vocal cord mucosal waves were recovered in all patients. Conclusions : Subjective voice quality and objective voice parameters were improved after operative management for laryngeal pathology and voice therapy. And we observed recovery of vocal fold mucosal waves by laryngeal stroboscopy. We think that early preventable tracheotomy is necessary to reduce the laryngeal contact injury in laryngeal inhalation patients.

• 대한후두음성언어의학회지
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• 제15권2호
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• pp.112-117
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• 2004

Background and Objectives : This study is purposed to investigate the statistically significant discrimination model for predicting vocal fold nodule and polyp's lesional grade, with patients' background data and objective voice evaluation parameters. Materials and Method : The retrospective research was carried out at the Ewha Womans University Hospital. 122 patients' voice examination data had been selected, and lesion screening (Grade I, II, and III) was conducted by 2 ENT specialists, with each patient's vocal fold pictures achieved during the laryngoscopy examination. Results : The Lesional Grade Discrimination Model with which the lesional grade of vocal fold nodules and polyps could be predicted was derived by the ordinal logistic regression analysis (using SPSS 10.0). With this model the lesional grades of 73 out of 122 patients(59.8%) were correctly predicted to their formerly screened ones. Conclusion : This model applied the multivariate approach, which statistically combined these currently used parameters, Jitter, Shimmer, MFR, MPT, and patient's background data such as gender and dysphonia period. It might explain the status of benign lesion of vocal folds, and furthermore expect the physiological function of vocal folds.