• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.2
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• pp.64-76
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• 2022

Praat is a useful analysis tool for linguists, engineers, doctors, speech-language pathologits, music majors, and natural scientists. Basic parameters including duration, pitch, energy and perturbation parameters such as jitter and shimmer can be easily measured and manipulated in the sound editor. When a more in-depth analysis is needed, it is recommended to understand the advanced menus of the object window and learn how to use them. Among the object window menus, vowel formant analysis, spectrum analysis, and cepstrum analysis can be cited as useful ones in the clinical field. The spectrum object can be usefully used for voice quality measurement and diagnosis of patients with voice disorders by showing the energy distribution according to frequency axis (domain). A cepstrum object is useful for speech analysis when periodicity of the sound object is not measurable. The low to high ratio obtained from the spectral object and the CPPs measured from the cepstrum object have attracted many researchers, and it has been proven that the CPPs measured in Praat are relatively excellent.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.494-497
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• 2010

본 논문에서는 $C_2H_5OH$를 주성분으로 하고 있는 알코올량에 따른 음성학적 분석 요소값의 변화를 측정하였다. 이를 위해 알코올 섭취량의 변화를 측정하고 다양한 음성 분석기법을 적용한 실험 과정을 수행하였다. 따라서 본 연구의 결과를 토대로 다양한 환경에 용이하게 쓰일 수 있도록 알코올 섭취와 관련된 분야에 적용 가능한 실험 절차를 수행하였다. 따라서 본 논문에서는 음성 분석 요소의 Pitch값과 Shimmer 및 Jitter에 대해 분석을 수행하였으며 실험 결과를 통해 알코올 섭취량이 음성에 미치는 영향을 분석하였다. 최종적으로 실험에 의해 제안한 방법의 유용성을 입증하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.113-116
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• 2007

In this paper, our proposed Nonlinear Autoregressive Exogenous (NARX) based on Least Square-Support Vector Regression (LS-SVR) is introduced and tested for producing natural sounds. This nonlinear synthesizer perfectly reproduce voiced sounds, and also conserve the naturalness such as jitter and shimmer, compared to LPC 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 speech modeling using NARX based on LS-SVR can successfully reconstruct synthesized sounds nearly similar to original voiced sounds.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.1
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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.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.2
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• pp.98-103
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• 2003

Background and Objectives : Although many studies have examined the effect of drinking on voice change, its cause and degree remain unclear. Since voice change occurs more frequently the day following drinking, rather than immediately afterwards, we examined whether the voice change was correlated with reflux laryngitis due to gastroesophageal motor disturbances. Subjects and Methods : For this study, 10 patients were selected who had neither voice change nor symptoms of reflux laryngitis at baseline (male : female=5 : 5, mean age=28 years old) They were subjected to psychoacoustic, acoustic, and aerodynamic tests and video stroboscopy at 4:00 P.M. the day before drinking (test 1), at 8:00 A.M. (test 2) and 4:00 P.M. (test 3) on the following day. On the day of drinking, the subjects had to drink more than their usual amount of Soju(Korean liquor) and were not allowed to talk much. The stroboscopy findings were quantified using the PC Belafsky score. Results : The laryngeal response to gastric reflux after drinking was compared between tests 1 and 2. In both tests, laryngeal edema and injection were observed on video stroboscopy. The psychoacoustic test detected more severe hoarseness in test 2 than in test 1. In addition, the acoustic test detected a mild increase in both jitter and shimmer. However, the differences between tests 2 and 3, which were performed when there was reduced or no gastric reflux, were not significant. Conclusions : Drinking may cause gastric reflux, which produces reversible voice change by irritating the vocal cords and larynx. Therefore, reflux laryngitis should be suspected in a patient whose voice changes markedly after drinking.

• Phonetics and Speech Sciences
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• v.1 no.2
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• pp.43-49
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• 2009

Vocal polyps are benign phonotraumatic lesions which are traditionally treated using phonomicrosurgical techniques. In the case of hyperfunctional voice use, voice therapy is effective and results in voice improvement. However, the utility of voice therapy about vocal polyp is in great demand. The purpose of this study was to evaluate the effects of voice therapy in patients with vocal polyps. The authors reviewed the medical records of 193 patients with vocal nodules or vocal polyps, and 64 patients (31 nodules and 33 polyps) were enrolled. All of the subjects had received explanation of problems, vocal hygiene education, and been treated by the $SKMVTT^{(R)}$ (Seong-Tae Kim's multiple voice therapy technique) ranging from 4 to 16 sessions (mean: 8.6 sessions). All subjects were examined by perceptual assessment, acoustic and aerodynamic measures, and VRP (voice range profile). In perceptual assessment, patients with vocal nodules had more breathy and strained voices than the vocal polyp group. Both groups significantly reduced rough, breathy voice after voice therapy. Patients with vocal polyps had worse voice quality than patients with nodules in acoustic measures. Both groups showed reduced jitter and shimmer after voice therapy. In aerodynamic measures, MPT and Psub were increased, and MFR was reduced (p<.05). Participants' frequency range and intensity range were increased after voice therapy, but only frequency range resulted in a significant difference (p<.05). In conclusion, the therapeutic effect of voice therapy in patients with vocal nodules and polyps was demonstrated perceptually and acoustically. We can suggest that voice therapy, including advice, vocal hygiene, and $SKMVTT^{(R)}$ is a useful as an initial choice of treatment for patients with vocal polyps before considering a surgical approach.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.2
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• pp.131-135
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• 2009

Background and Objectives: Benign vocal fold lesions have shown various voice onset types on phonation, however, they have not been documented yet. We studied to know the relationships between benign vocal fold lesions and voice onset types. Materials and Method: 114 subjects were evaluated by using videokymographic examinations. The subjects were classified into three types: normal, contact, and open types according to the patterns of voice onset types on phonation. Benign vocal fold lesions were investigated and voice onset types were compared between normal and disease groups. Voice parameters were obtained from and compared in all subjects to assess acoustic and aerodynamic factors. Results: The normal type among onset types were more than contact type or open type in both normal and disease groups. Disease group showed many contact and open types when. compared with normal group. Vocal nodule and vocal polyp were showed many normal and contact types, however, sulcus vocalis was almost showed open type among voice onset groups. The values of mean flow rate (MFR) of contact type were significantly higher compared to normal type in disease group (p<0.05). Shimmer of contact type was higher than normal type in diseasegroup, but the difference was not significant (p=0.057). Conclusion: Benign vocal fold lesions were related to the various types of voice onset. The various types of voice onset should be considered when benign vocal fold lesions were examined.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.15 no.2
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• pp.92-97
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• 2004

Background and Objectives : The purpose of this study was to examine objectively pre and post operative voice quality evaluation and intelligibility of alaryngeal voice using speech recognition program, HUVOIS. Materials and Methods : 2 laryngologists and 1 speech pathologist were evaluated 'G', 'R', 'B' in the GRBAS sclae and speech intelligibility using NTID rating scale from standard paragraph. And also acoustic estimates such as jitter, shimmer, HNR were obtained from Lx Speech Studio. Results : Speech recognition rate was not significantly different between pre and post operation for pathological vocie samples though voice quality(G, B) and acoustic values(Jitter, HNR) were significantly improved after post operation. In Alaryngeal voices, reed type electrolarynx 'Moksori' was the highest both speech intelligibility and speech recognition rate, whereas esophageal speech was the lowest. Coefficient correlation of speech intelligibility and speech recognition rate was found in alaryngeal voices, but not in pathological voices. Conclusion : Current study was not proved speech recognition program, HUVOIS during telephone program was not objective and efficient method for assisting subjective GRBAS scale.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.15 no.2
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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.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.17 no.1
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• pp.43-48
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• 2006

Background and Objectives: Countertenors who can produce higher vocal pitch like female classical singer's voice and use both modal and falsetto register. This study was conducted to study phonatory characteristics between modal and falsetto register of the countertenor. Materials and Methods: A male countertenor who had 8 years of experience was examined using a videostroboscopy and his voice was analyzed using aerodynamic measures; fundamental frequency(F0), Mean air flow rate(MFR), intensity(SLP), subglottal air pressure(Psub) with phonatory function analyzer(Nagashima) and acoustic measures; jitter, shimmer, HNR, closed quotient(CQ) using a Electro-glottography(EGG) of Lx. Speech Studio(Laryngoscope, Ltd, UK) and voice range profile of CSL(Kay elemetrics). Results: In the stroboscopy finding, the longitudinal length of vocal folds was increased at the falsetto register and the upper margin of vocal folds vibrated with incomplete closure of true vocal folds. In aerodynamic analysis, intensity was same at the modal and falsetto register. However, MFR, Psub, MPT were higher at the falsetto register. In the electroglottographic analysis, closed quotient(CQ) at the modal register was high and also much higher at the high-pitch falsetto than at the loud falsetto. In the VRP, intensity was similar though F0 was different between modal and falsetto register. Conclusion: It implied that countertenor could produce powerful voice quality by increasing of respiratory pressure and respiratory volume though glottal closure was incomplete. In addition, no change of EGG waveform, similar voice range with alto was observed.