• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.7
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• pp.957-963
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• 2007

In this paper, Nonlinear Autoregressive (NAR) method based on Least Square-Support Vector Regression (LS-SVR) is introduced and tested for nonlinear sustained vowel modeling. In the database of total 43 sustained vowel of Benign Vocal Fold Lesions having aperiodic waveform, this nonlinear synthesizer near perfectly reproduced chaotic sustained vowels, and also conserved the naturalness of sound such as jitter, compared to Linear Predictive Coding does not keep these naturalness. However, the results of some phonation are quite different from the original sounds. These results are assumed that single-band model can not afford to control and decompose the high frequency components. Therefore multi-band model with wavelet filterbank is adopted for substituting single band model. As a results, multi-band model results in improved stability. Finally, nonlinear sustained vowel modeling using NAR based on LS-SVR can successfully reconstruct synthesized sounds nearly similar to original voiced sounds.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.75-82
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• 2010

Many previous studies based on respiratory characteristics of Idiopathic Parkinson's Diseases (IPD) patients have not controlled related factors appropriately. Accordingly, these studies produced discordant results. Furthermore, there is currently a lack of studies that can provide precise explanations on the characteristics of respiration and phonation. This study included a total of 40 subjects: 20 mixed gender de novo IPD patients ranging in age from 50 to 80 (Hoehn & Yahr stage 1~3), and 20 normal subjects with similar matches for age and gender. All participants were controlled based on their gender, age, height, weight, vocal fold function, cognitive abilities, and depression factors. K-MMSE (Korean-Mini Mental State Examination), nVHI-10 (new Voice Handicap Index), and KGDS (Korean Form of Geriatric Depression Scale) were evaluated to select this study subjects. In order to compare respiratory functions between the two groups, FVC, FEV1, and FEV1/FVC were measured using microQuark, a PC-based spirometer. CSL was used by measure MPT and PAS was used to measure MFR. To investigate the characteristics of phonation ability, CSL was used to measure jitter and shimmer, while PAS was used to measure Psub. In order to compare the respiratory function averages and phonation ability between the two groups, statistical analysis was conducted using SPSS (version 12.0). The results of this study showed that most de novo IPD patients were included in the normal average range of respiratory and phonatory ability. But the respiratory and phonatory ability of de novo IPD patients showed lower tendency as compared with the normal group. When the average of respiratory and phonatory ability among the gender was compared, the difference of males was greater than the difference of females.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.1
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• pp.31-36
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• 2022

Background and Objectives Proton pump inhibitors (PPIs), mucolytics, and steroids were commonly recommended after phonomicrosurgery to prevent worsening of vocal fold (VF) scar formation and subglottal swelling. However, there is no consensus about whether laryngeal reflux and thick discharge are associated with the voice outcomes following phonomicrosurgery in benign VF lesions. The purpose of this study is to examine voice outcomes of use of PPIs, mucolytics,and steroids after phonomicrosurgery. Materials and Method This randomized controlled study is performed with patients undergoing laryngomicroscopic surgery for VF polyp and cyst. Participants were randomly assigned to 1) no medication, 2) PPIs, 3) PPIs+mucolytics, and 4) PPIs+mucolytics+steroids for 2 months postoperatively. Grade, roughness, breathiness, asthenia, and strain (GRBAS) scale, stroboscopic examination, aerodynamic assessment, acoustic analysis, and Voice Handicap Index-10 (VHI-10) were performed pre- and post-operatively at 2 months. Parameters were compared among four groups. Results Among 85 patients, a total of 50 patients were included. The VHI-10, perceptual and acoustic parameters improved in all groups after surgery. However, there was no significant difference in those parameters among all groups. Conclusion PPIs, mucolytics, and steroids did not significantly influence voice outcomes after phonomicrosurgery in patients with benign VF lesions.

• Clinical Endoscopy
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• v.56 no.5
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• pp.594-603
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• 2023

Background/Aims: The necessity for pharyngeal anesthesia during upper gastrointestinal endoscopy is controversial. This study aimed to compare the observation ability with and without pharyngeal anesthesia under midazolam sedation. Methods: This prospective, single-blinded, randomized study included 500 patients who underwent transoral upper gastrointestinal endoscopy under intravenous midazolam sedation. Patients were randomly allocated to pharyngeal anesthesia: PA+ or PA- groups (250 patients/group). The endoscopists obtained 10 images of the oropharynx and hypopharynx. The primary outcome was the non-inferiority of the PA- group in terms of the pharyngeal observation success rate. Results: The pharyngeal observation success rates in the pharyngeal anesthesia with and without (PA+ and PA-) groups were 84.0% and 72.0%, respectively. The PA- group was inferior (p=0.707, non-inferiority) to the PA+ group in terms of observable parts (8.33 vs. 8.86, p=0.006), time (67.2 vs. 58.2 seconds, p=0.001), and pain (1.21±2.37 vs. 0.68±1.78, p=0.004, 0-10 point visual analog scale). Suitable quality images of the posterior wall of the oropharynx, vocal fold, and pyriform sinus were inferior in the PA- group. Subgroup analysis showed a higher sedation level (Ramsay score ≥5) with almost no differences in the pharyngeal observation success rate between the groups. Conclusions: Non-pharyngeal anesthesia showed no non-inferiority in pharyngeal observation ability. Pharyngeal anesthesia may improve pharyngeal observation ability in the hypopharynx and reduce pain. However, deeper anesthesia may reduce this difference.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.6.1-6
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• 1982

Papilloma is the common benign tumor of the larynx and the incidence of its malignant change was variable. The authors recently experienced 2 cases of squamous cell carcinoma of the larynx which were considered to be transformed from laryngeal papilloma. Case 1. A 58 year old male patient visited O.P.D. of Department of Otolaryngology of Busan National University Hospital, because of hoarseness for 3 years on May 13th, 1980. At that time, local finding of indirect laryngoscopy revealed whitish hypertrophic papillomatous mass on both vocal cords and anterior commissure, and dirty gray white pseudomembrane on left aryepiglottic fold, and the result of biopsy was squamous cell papilloma. So the laryngeal papilloma was removed under suspension laryngoscopy and then he had no specific treatment in spite of being recommended 5-FU topical spray. On March 5th, 1981, he visited O.P.D. again because of progressive exacerbation of hoarseness with mild dyspnea and histopathological finding was revealed squamous cell carcinoma of the larynx. Seven days later from that day, he visited emergency room due to severe dyspnea, and emergency tracheostomy was performed on sitting position. On April 7th 1981, total laryngectomy was performed successfully and postoperative irradiation therapy was recommended. Case 2. A 47 year old male patient visited our O.P.D. because of hoarseness for 5 years on Sep. 27, 1978. At that time, local finding of indirect laryngoscopy revealed papillomatous mass on left vocal cord and left ventricle and result of biopsy was squamous cell papilloma. So he had been treated with 11 times removal of papilloma, topical spray of 5-Fu and estrogen for 3 years, but the papilloma had been recurred. On Sep. 9th, 1981, he visited O.P.D. because of severe dyspnea and emergency tracheostomy and biopsy was performed. The result of biopsy was squamous cell carcinoma of larynx and total laryngectomy was performed successfully.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.2
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• pp.126-132
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• 2001

Background and Objectives : Signal traduction through phospholipase C(PLC) participate in the regulation of cell growth and differentiation. Growth factors bind to their receptors and thereby induce tyrosine phophorylation of the phospholipase C-${\gamma}$1(PLC-${\gamma}$1). PLC-${\gamma}$1 is a substrate for several receptor tyrosine kinases and its catalytic activity is increased by tyrosine phosphorylation. Tyrosine kinase phosphorylation of PLC-${\gamma}$1 stimulates PLC activation and cell proliferation. However the signal transduction pathway and the significance of PLC in injured recurrent laryngeal nerve regeneration is unknown. Therefore after we obtained fuctionally recovered rats using PEMF in this study, we attempt to provide some evidence that PLC plays a role in nerve regeneration itself and regeneration related to PEMF through the analysis of the difference between fucntional recovery group and non-recovery group in the recurrent laryngeal nerve. Materials and Method : Using 32 healthy male Sprague-Dawley rats, transections and primary anastomosis were performed on their left recurrent laryngeal nerves. Rats were then randomly assigned to 2 groups. The experimental group(n=16) received PEMS by placing them in custom cages equipped with Helm-holz coils(3hr/day, 5days/wk, for 12wk). The control group(n=16) were handled the same way as the experimental group, except that they did not receive PEMS. Laryngo-videoendoscopy was performed before and after surgery and followed up weekly. Laryngeal EMG was obtained in both PCA and TA muscles. Immunohistochemisty staining and Western blotting analysis using monoclonal antibody was performed to detect PLC-${\gamma}$1 in recurrent laryngeal nerve and nodose ganglion. Results : 10 rats(71%) in experimental group and 4 rats(38%) in the control group showed recovery of vocal fold motion. Functionally-recoverd rats show PLC-${\gamma}$1 positive cells in neuron and ganglion cells after 12 weeks from nerve injury. Conclusion : This study shows that PLC1-${\gamma}$ involved in singnal trasduction pathway in functinal recovery of injured recurrent laryngeal nerve and PEMF enhance the functional recovery by effect on this molecule.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.1
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• pp.5-11
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• 1997

To set up an objective basis for the evaluation of the stroboscopic findings, video-strobolaryngoscopic images of vocal fold vibration in 5 female and 5 male normal speakers were analyzed using an image analysis computer program called KSIP(Kay Storoboscopy Image Processing, Kay Elemetrics Corp., NJ, USA). Four consecutive vibratory cycles were compared in comfortable, louder, high-pitched /ee/ phonation for every subject. findings mostly replicated earlier studies including glottal chinks which were observed in most female speakers throughout the cycles and clear distinction between female and male speakers in their vibratory patterns as well as intensity and frequency-re-lated differences. However, there were some findings incompatible with those from previous studies which may be attributable to technical problems. This study may provide an objective basis of the stroboscopic findings such as image shape, amplitude, area, and their changes according to frequency and intensity variations. We anticipate that funker study with larger samples ran provide an objective criteria for normal vibratory characteristics of the laryngostro-boscopic findings.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.22 no.2
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• pp.137-142
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• 2011

Background and Objectives : The aim of this study is to introduce Korea version of pediatric VHI and to compare pVHI-K scores between children with dysphonia and children without voice problems before pVHI-K is developed as a preliminary study. Additionally, the relationship between pVHI and acoustic measures were investigated. Materials and Methods : pVHI-K scores in normal group were obtained from 15 parents who have children with no present or past history of a voice disorder, hearing loss, or related disability that can affect the their voice or speech. Dysphonia group consisted of 15 parents who have children with bilateral vocal fold nodule's at Department of Otolaryngology, the Seoul National University Hospital (SNUH). pVHI-K and acoustic parameters were measured in two group. Results : The mean pVHI scores (total, functional, physical, emotional) in normal group were 2.33 (T), 0.80 (F) 1.33 (P) and 0.27 (E), respectively whereas those of pVHI in children group with dysphonia were 23.13 (T), 11.07 (F), 5.73 (P) and 6.13 (E), respectively and significant differences were revealed in total pVHI score as well as in all of the sub-pVHI scores. Moreover, significant correlation between pVHI-K parameters (T, F, P) and acoustic measures [Shimmer(%)] were shown in children in dysphonia group. Conclusion : Reported by parents can be useful as a supplementary clinical tool for diagnosing and measuring treatment effectiveness in young children with dysphonia.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.45-56
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• 2022

This paper proposes an optimal methodology for automatically diagnosing and predicting the severity of the chronic kidney disease (CKD) using patients' utterances. In patients with CKD, the voice changes due to the weakening of respiratory and laryngeal muscles and vocal fold edema. Previous studies have phonetically analyzed the voices of patients with CKD, but no studies have been conducted to classify the voices of patients. In this paper, the utterances of patients with CKD were classified using the variety of utterance types (sustained vowel, sentence, general sentence), the feature sets [handcrafted features, extended Geneva Minimalistic Acoustic Parameter Set (eGeMAPS), CNN extracted features], and the classifiers (SVM, XGBoost). Total of 1,523 utterances which are 3 hours, 26 minutes, and 25 seconds long, are used. F1-score of 0.93 for automatically diagnosing a disease, 0.89 for a 3-classes problem, and 0.84 for a 5-classes problem were achieved. The highest performance was obtained when the combination of general sentence utterances, handcrafted feature set, and XGBoost was used. The result suggests that a general sentence utterance that can reflect all speakers' speech characteristics and an appropriate feature set extracted from there are adequate for the automatic classification of CKD patients' utterances.