• 대한후두음성언어의학회지
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• 제24권2호
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• pp.107-111
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• 2013

Objectives : We developed two-dimensional (2D) scanning videokyomography to evaluate the mucosal wave of whole vocal cords in real time to overcome the limit of preexisting stroboscopy and line scanning videokymography which could not evaluate it. Methods : We implemented a continuous light source with high brightness, a high-definition CMOS camera, and capture board for saving the data. We created the software program to analyze the image data from the system. The test of the functionality of the 2D scanning videokymography camera was performed in one of the authors (P.H.J 32 years old male). Vocal cord images were obtained during normal phonation and falsetto phonation. Images were obtained also during cough, diplophonia. Results : The system made it possible to measure objective parameters, including fundamental frequency, amplitude, regularity, mucosal wave, and phase difference, medial and lateral peak, opening versus closing duration related to vocal fold vibration. Simultaneously, it enabled analysis of the whole mucosal wave of the entire vocal fold in real time. 2D scanning videokymography was also effective for evaluating the dynamic status of the vocal fold when the subject phonated aperiodic voice. Conclusion : In conclusion, 2D scanning videokymography can support the analysis of the whole mucosal wave of the entire vocal cord with objective vocal parameters, overcoming the limitations of stroboscopy and previous line scanning videokymography techniques.

• 말소리와 음성과학
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• 제1권2호
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• pp.163-171
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• 2009

This study attempted to investigate vocal characteristics and differences in gender and voice classification among classical singers. Twenty-three female singers (M = 23.1 yrs, SD = 3.6 yrs, average 6.3 yrs singing experience, all classified as sopranos) and twenty male singers (M = 25.2 yrs, SD= 3.6 yrs, average 6. 3 yrs singing experience, 8 tenors, 12 baritones) were recruited to participate in the present study. Speaking fundamental frequency (FO), closed quotient (CQ), MPT (Maximum Phonation Time), breathing types, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), and singers' formants were measured. In addition, vibratory patterns were observed using stroboscopy. Sfo, singing CQ, breathing types, formant frequency in singers' formants, MIP, MEP, and MPT were significantly different from gender to gender. Generally, singers' formants were observed in male singers and also the pattern of singers' formants was different between tenors and baritones. Lower singing CQ values were observed than speaking CQ values in the female singers (P<.001). Furthermore, MEP, MIP, and singing CQ were significantly lower for female singers than for males singers (P<.001). MPT and speaking FO, however, were not significantly different between tenors and baritones.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권8호
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• pp.417-422
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• 2006

This paper presents the effect of driving waveform for piezoelectric bend mode inkjet printhead with optimized mechanical design. Experimental and theoretical studies on the applied driving waveform versus jetting characteristics were performed. The inkjet head has been designed to maximize the droplet velocity, minimize voltage response of the actuator and optimize the firing frequency to eject ink droplet. The head design was carried out by using mechanical simulation. The printhead has been fabricated with Si(100) and SOI wafers by MEMS process and silicon direct bonding method. To investigate how performance of the piezoelectric ceramic actuator influences on droplet diameter and droplet velocity, the method of stroboscopy was used. Also we observed the movement characteristics of PZT actuator with LDV(Laser Doppler Vibrometer) system, oscilloscope and dynamic signal analyzer. Missing nozzles caused by bubbles in chamber were monitored by their resonance frequency. Using the water based ink of viscosity of 4.8 cps and surface tension of 0.025 N/m, it is possible to eject stable droplets up to 20 kHz, 4.4 m/s and above 8 pl at the different applied driving waveforms.

• 음성과학
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• 제15권3호
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• pp.145-156
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• 2008

The goal of this study was to investigate acoustic and physiologic characteristics of two phonation types of 'Khoomei' which is a traditional singing style of people who live around the Altai mountains or Mongolia region. It can be produced two pitches simultaneously - high melody pitch can be perceived along with a low drone pitch. Sygyt and kargyraa styles are the most popular and identifiable styles and they can be recognized as the different sounds depending on the method of voice production. Two trained Mongolians participated and have used at least 5 - 6 years. The characteristics of this voice production were measured by using flexible fiberscope, Stroboscopy, Lx Speech studio, Spead, and Doctor Speech. In Sygyt style, very high vocal fold closure (71.50%) with both true and false vocal folds contact and strong breathing support was observed. They also showed that tongue height and harmonics were increased (around 10dB) with resonance cavity movement. In contrast, it was found that Kargyraa sound had very low pitch with relaxed stomach, less laryngeal tension and lower vocal fold contact (69.50%) than hard Sygyt style sound without raising the tongue during phonation. 'Khoomei' phonation can be made by strong contact of both true and false vocal folds and by increasing the harmonics as well.

• 대한후두음성언어의학회지
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• 제21권1호
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• pp.17-21
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• 2010

Dysphonia is a medical terminology for voice disorders characterized by hoarseness, harshness, weakness, or even loss of voice ; any impairment in ability to produce voice sounds using the vocal organs, larynx, The causes of dysphonia can be classified into two groups, organic and functional. Functional dysphonia includes spasmodic dysphonia, muscle tension dysphonia, mutational dysphonia and conversion dysphonia, etc, The findings of laryngoscopy in these dysphonia are almost normal. Therefore, physicians should diagnosis these diseases from careful history taking and abundant understandings about the phonation pattern, Organic dysphonia is caused by anatomical problems in the larynx, especially on the vocal fold, Some lesions, however, are not easily found because these lesions are too small, or located on the lower lip of vibrating vocal fold. Laryngopharyngeal reflux induced laryngitis, vascular lesions, sulcus vocalis, vocal atropy including presbylaryngis, and mucosal tears are common lesions easily missed in laryngoscopy, Therefore, a high index of suspicion is necessary to avoid missing vocal fold mucosal lesions, and the strobovideolaryngoscopy is indispensable in making the diagnosis,

• 말소리와 음성과학
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• 제7권2호
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• pp.47-54
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• 2015

The objectives of this study are to research the frequency of depression symptom in patients with voice disorders and to investigate parameters associated with depression from voice evaluation. A hundred ninety six patients(106 males and 90 females) who had been diagnosed with voice disorders first in their lifetime were selected. All the patients were examined by laryngeal stroboscopy. For depression and voice study, personal interview, acoustic and aerodynamic analysis, voice handicap index(VHI), reflux symptom index(RSI), and beck depression index(BDI) were done respectively. Mild to severe BDI were seen in 26.2%(52 patients) of the whole patients. A BDI mean score of female patients was $8.8{\pm}7.5$ which was higher than that of male patients($5.6{\pm}6.6$), the difference observed being statistically significant(p<0.001). In the acoustic analysis, the score of sent_duration parameter was increasing in the patients with depression, which was significantly higher than the score of the patients without depression(p<0.05). In the addition, the scores of VHI and RSI were higher in the patients with depression(p<0.001). Our findings suggest that the prevalence of depression in patients with voice disorders is related to female, speaking velocity, and self-questionnaire. This result can be used for psychologically based approach to therapy.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1993년도 제27차 학술대회 초록집
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• pp.72-72
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• 1993

음성질환의 진단을 위하여 사용하는 검사법은 여러가지가 있으며 음성발생의 기전에 근거하여 공기역학적 검사로부터 어음청취검사에 이르기까지 다양하게 시도되고 있다. 이중 성대점막의 진동양상은 간접후두경 만으로는 정확히 관찰하기 어려우므로 후두스트로보스코피, 초고속촬영법, 광전, 전기, 초음파등을 이용한 글로토그라피 및 카이모그라피 등이 사용되고 있는데 임상적으로는 후두스트로보스코피가 가장 널리 사용되어지고 있다. 저자들은 1992년 4월 부터 1993년 3월까지 연세대학교 의과대학 음성언어의학연구소에서 음성검사를 시행하였던 환자들을 대상으로 질환별 스트로보스코피소견의 특징을 파악함으로써 후두질환의 진단 및 치료에 도움을 얻고자 하였다.

• 대한후두음성언어의학회지
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• 제32권1호
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• pp.1-8
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• 2021

Human vocal cords vibrate as quickly as 100-250 times per second, so it is impossible to observe them with normal endoscopic diagnostic equipment. High-speed videolaryngoscopy (HSV) allows the visualization of non-periodic vibratory motion of vocal fold beyond the limitation of videostroboscopy. New developed post-processing methods that converts HSV to two-dimensional videokymography (2D VKG) using U-medical image-processing software can provide quantitative information on vocal fold mucosa vibration. Multifunctional laryngeal examination system is composed of 3 kinds of examinations such as HSV, 2D scanning digital kymography (2D DKG) and line scanning digital kymography (DKG). Evaluation of entire vocal cord vibratory pattern in each cord is possible using 2D DKG and a faster and more reliable quantitative information can be obtained. As this system is used in clinical and research, it is expected to bring much advances to the diagnosis of voice disorders. In this review, I will introduce the principles and advantages on examination of the vocal fold vibration, which is in the spotlight recently, and proceed with the literature review.

• 대한후두음성언어의학회지
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• 제17권1호
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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.

• 대한후두음성언어의학회지
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• 제27권1호
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• pp.40-44
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• 2016

Background and Objectives : Surgery is considered the primary treatment for intracordal cyst. However, patients who had undergone surgery are still subject to recurrence and continued voice changes. Intracordal cysts naturally disappear in some patient population. Cyst does not always recur in patients who had received partial surgical removal, too. Contradicting results raises a question whether complete surgical removal of intracordal cyst is necessary and demonstrate need for better treatment. Herein, the author proposes novel surgical method technique intralaryngeal needle technique (INT), a technique using surgical needle for not only injection but also for aspiration and excision of cyst. This study aims to examine the potential of intralaryngeal needle technique in treating intracordal cysts. Materials and Methods : Surgical procedures were done on in-patients diagnosed with intracordal cyst. 23 patients received follow-up screening after the surgery for one year. Patients' subjective satisfaction levels, acoustic measures, aerodynamic measures, laryngeal stroboscopic results were compared before and after the treatment. Results : Overall patients were satisfied with novel surgical excision method. In terms of aerodynamic measures, maximum phonation time, mean air flow rate improved after the surgery. In terms of acoustic measures, Jitter, Shimmer, NHR, and voice pitch changes after the treatment showed statistically significant differences. Laryngeal stroboscopy results showed significant decreases in cyst sizes. Post-surgery patients had improved mucosal waves and amplitudes values. Conclusion : The results show the validity of intralaryngeal needle technique in reducing intracordal cyst size by excision, aspiration, and injection. The author believes this novel technique can be used as an alternative surgical method for intracordal cysts.