• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.24 no.1
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• pp.28-32
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• 2013

Because the human voice is produced through vibration of the vocal cords during the exhalation of airflow, it is important to observe the vibration pattern of the vocal cords in patients complaining of voice changes. However, it is not easy to observe the actual vibration pattern of the vocal cord because it vibrates so fast that it cannot be observed by the naked eye and it is located deep in the throat. Recently, with advances in instruments, including laryngoscopes and video camera systems, the vibration pattern of the vocal cords can now be observed. However, considering that present video camera systems can detect 30-60 images per second and the vocal cord vibrates at 100-200 and 200-300 times per second in men and women, respectively, it is not possible to record the whole mucosal wave of the vocal cord in real time. To overcome this limitation, a stroboscope, which converts fast movements of the vocal cord into slower images, has been developed. Since then, several instruments were developed to examine vocal vibration pattern. However, each instruments have advantages and disadvantages. Therefore, we should know about these things to apply them in patients with voice problem.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.32 no.1
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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.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.343-349
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• 2004

Electroglottograph(EGG) is a signal recorded from the vocal cord vibration by measuring electrical impedance across the vocal folds through the neck skin. The purpose of this study was to develop EGG system and to evaluate possibility for the application on speech analysis and laryngeal disease diagnosis. EGG system was composed of two pairs of ring electrodes, tuned amplifier, phase sensitive detector, low pass filter, and auto-gain controller. It was designed to extract electric impedance after detecting by amplitude modulation method with 2.7MHz carrier signal. Extracted signals were transmitted through line-in of PC sound card, sampled and quantized. Closed Quotient(CQ), Speed Quotient(SQ), Speed Index(SI), fundamental frequency of vocal cord vibration(F0), pitch variability of vocal fold vibration (Jitter), and peak-to-peak amplitude variability of vocal fold vibration(Shimmer) were analyzed as EGG parameters. Experimental results were as follows: the faster vocal fold vibration, the higher values in CQ parameter and the lower values in SQ and SI parameters. EGG and speech signals had the same fundamental frequency. CQ, SQ, and SI were significantly different between normal subjects and patients with laryngeal cancer. These results suggest that it is possible to implement portable EGG system to monitor the function of vocal cord and to test functional changes of the glottis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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• pp.431-437
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• 2013

These days, many people live a healthy life, but suffering caused by chronic diseases. The main factors of chronic diseases are stress, blood pressure and obesity. Chronic diseases which are caused by high blood pressure are very high incidence. Therefore, this paper suggests the ways to prevent as diagnosis a phenomenon that occur rising in blood pressure consistently by analyzing the voice according th rising in blood pressure. For this, I studied some influence on voicing through rising in blood pressure by applying pitch that measure vocal fold vibration and intensity that measure voice energy size that is one of technique. That collect and analyse the voice after rising blood pressure by aerobic exercise.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.6 no.1
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• pp.22-26
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• 1995

Change of voice, espicially hoarseness show irregular vibration of vocal cord. So, computerized acoustic analysis has presented many acoustic parameters for objective evaluation of voice. We objectively investigated the vocal vibration of normal persons and hoarseness patients in Korea. The RAP(relative average perturbation), PPQ(pitch period perturbation quotient) and APQ(amplitude perturbation quotient) of normal persons were compared with that of hoarseness patients with multidimensional voice program for the possibility of distinguishing the pathologic vocal vibration from normal. Authors agree that RAP, PPQ and APQ showed interesting differences between the normal and the hoarseness patients by the multivariate statistical analysis. In conculusion, relative average perturbation, pitch period perturbation and amplitude perturbation quotient might be meangingful screening parameters distinguishing hoarseness patients from normal.

• Speech Sciences
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• v.12 no.4
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• pp.77-92
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• 2005

Voice is made by systemic interaction of respiration, vocalization, articulation and resonation. There is no existing multi-channel voice analysis system to assess voice and respiration simultaneously. The most existing systems consist of. vocal fold vibration measurement such as stroboscopy, EGG (electroglottography) or laryngeal electromyography and voice analysis system. Since respiration has close relationship with voice simultaneous analysis of both vocal cord vibration and respiration are essential. In this study, a four channel integrated system are developed for acoustic analysis through microphone, vocal fold vibratory analysis using EGG, and respiratory analysis using two channel RIP (respiratory inductive plethysmography).

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.71-71
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• 1993

Diplophonia is produced by the voice of two separate tones and produced through quasi-periodic variations in the vocal cord vibration. Diplophonia is generally regarded as a symptom of laryngeal pathology. The difference in the vibratory frequency between the vocal cords can be seen in a tension imbalance and a difference in the level of the vocal folds under the special condition such as incomplete glottal closure. So authors have experienced 19 cases of patient with diplophonia for the unilateral vocal cord paralysis, intracordal cysts and other mass lesions. And we analysed the diplophonic voice with peak variability and noise level for the quasi-periodic waveforms and spectrograms pre-and postoperatively.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.24 no.2
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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.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.5 no.1
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• pp.69-74
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• 1994

Thyroplasty type III provides an effective mean of shortening the vocal fold. It is used primarily fer lowering vocal pitch. The indications for this surgery are the male patients with too high a vocal pitch of long duration which has proven resistant to voice therapy and a type of dysphonia characterized by high pitch and a breathy voice, in which the laryngeal findings include a very narrow glottal chink and a small amplitude of vibration, suggesting a stiff vocal cord. In this study, we have experienced two cases of high pitched voice, one is mutational falsetto and other is high pitched, breathy voice with stiff vocal fold. The results were satisfactorily successful with type III thyroplasty. So we report the cases of type III thyroplasty in patients of dysphonia with high pitched voice.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.26-32
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• 2007

Objective and Background: Laryngeal stroboscope is an useful equipment in evaluation of vocal cord vibration and in early detection of mucosal lesion including invasive cancer of the vocal cord. Recently Lee et al. (2006) developed portable stroboscope using voice as synchronization signal. It has been frequently impaired ability to synchronize the flashes even in normal female. Authors tried to investigate various methods including vibration pick-up, microphone, laryngeal microphone, and contact microphone for development of simple and accurate method like electroglottograph signal. The purpose of this study was to estimate wheher the vibration pick-up is available and is consistent with the signal of EGG. Subjects and Methods: Authors compared the signals between EGG and noncontact method such as voice, contact methods including vibration pick-up, laryngeal microphone, and contact microphone in normal twenty adults (male 10 and female 10). The number of peak in one cycle was compared with the number of the peak in EGG, and the percent of phase difference in the peak was compared with EGG Also, authors tried to investigate which site of vibration pick-up was most effective for synchronization of stobo flashes. Three site including anterior neck below the cricoid cartilage, thyroid ala, and suprahyoid region were analysed. Results: Among various methods for synchronization of strobo flashes, vibration pick-up was most effective method in peak detection. And anterior neck below cricoid cartilage was the most available site of the vibration pick-up. Conclusion: Authors suggest that vibration pick-up is most available and effective method for synchronization of strobo flashes.