• Proceedings of the KSLP Conference
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• 1998.11a
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• pp.210-210
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• 1998

Vocal fold vibration is essentially the propagation of a mucosal wave, starting from the lower surface of the vocal fold. The mucosal upheaval (MU), where the mucosal wave starts and propagates upward, appears only when the vocal fold vibrates. We investigated the location of the mucosal upheaval in response In variations in vocal fold tension. Vibrations were elicited under three conditions: during bilateral thyroarytenoid (TA) muscle contraction, without TA muscle contraction and during vocal fold lengthening. TA muscle contraction was obtained by direct electrical stimulation of the muscle. The vocal fold was lengthened by cricothyroid (omitted)

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.9-11
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• 2004

The vocal folds play an important role to produce glottal pulse which is an essential factor of phonation. There have been some models which implement the vocal folds' dynamics, such as one-mass model, two-mass model, multi-mass model and ribbon model. Among them, this paper uses nonlinear two-mass model, which is simple structure and produces similarly real glottal pulses and vocal folds' vibration, to realize vocal folds digital model. The pattern of movements in vocal folds will be shown in this paper by using vocal folds digital model. It will be verified how initial position of vocal folds. variation of tension and change of lung pressure influences vibration and glottal pulses.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.5 no.1
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• pp.38-43
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• 1994

Though normal vocal cords show regular vibration, pathologic vocal cords show irregularity between peaks. Jitter means fluctuation in the time interval between peaks, and Shimmer means cycle to cycle variation in the amplitude of the peaks. We investigated the vocal vibration of Korean normal persons objectively. The fundamental frequency, Jitter, Shimmer and SNR(signal to noise ratio) of normal persons were compared with that of vocal Polyp Patients with CSpeech Program for the possibility of distinguishing the pathologic vocal vibration from normal. The results were as follows ; Comparing the fundamental frequency of vocal Polyp Patients with normal persons, great change was noted only in female cases. But the Jitter and Shimmer of vocal polyp patients were greater than normal significantly in both male and female cases. SNR was lower than normal in vocal polyp patients. In the conclusion, fundamental frequency, Jitter, Shimmer and SNR might be meaningful parameters distinguisuing pathologic vibration from normal.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.17 no.1
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• pp.56-59
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• 2006

The factors involved in controlling the vocal pitch are the tension, the mass, the length of the vocal cords and the subglottic pressure. Vocal pitch can be elevated surgically by increasing the stiffness or reducing the vibrating mass of the vocal cords. Recently, we experienced a case of 25 year-old female whose vocal pitch was elevated with radiofrequency surgery of right vocal cord on suspension laryngoscopy. Elevation of vocal pitch(134.11 to 144.73) was noted two months after operation. So we report this case with review of literature.

• MALSORI
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• no.56
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• pp.159-172
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• 2005

This paper analyzes the vocal tract area estimation algorithm used as a part of a speech analysis program to help deaf children correct their pronunciations by comparing their vocal tract shape with normal children's. Assuming that a vocal tract is a concatenation of cylinder tubes with a different cross section, we compute the relative vocal tract area of each tube using the reflection coefficients obtained from linear predictive coding. Then, we obtain the absolute vocal tract area by computing the height of lip opening with a formula modified for children's speech. Using the speech data for five Korean vowels (/a/, /e/, /i/, /o/, and /u/), we investigate the effects of the sampling frequency, frame size, and model order on the estimated vocal tract shape. We compare the vocal tract shapes obtained from deaf and normal children's speech.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.53-61
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• 2013

Voice disorders are most common in female teachers due to work-related vocal demands; however, only a few studies tried to evaluate individual risk factors with work-related risk factors to diagnose voice disorders. This study evaluated sixty-seven female elementary teachers (36 with voice disorders and 31 without voice disorders) to compare their vocal misuse, overuse, and vocal hygiene behaviors. Total Voice Handicap Index scores and VHI subscale (P, E, F) scores were not significantly different between two groups (p>0.05) and there was no relationship between VHI and acoustic measures (p>0.05). Loud talking, talking in noisy situations, and excessive speaking were significantly more frequent in female teachers with voice disorders (p<0.05) and thereby these overuse and misuse behavioral patterns were identified as risk factors to develop voice disorders in female teachers. Also, hydration was the most common behavior for vocal hygiene when experiencing vocal fatigue; however, hydration with hot green tea or coffee and throat clearing were often misused for vocal hygiene. This study found that female teachers from both groups presented higher voice handicap regardless of voice disorders. This study suggests a multidimensional voice assessment protocol is required to reflect voice problems in teachers and a vocal education program may be important to improve vocal hygiene knowledge and behavioral changes in female teachers.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.26 no.2
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• pp.97-100
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• 2015

Benign vocal fold lesions, such as vocal nodules, polyps and Reinke's edema, usually result from chronic voice overuse. Conservative management such as voice therapy and pharmacotherapy are used as the primary treatment techniques. The main purpose of voice therapy is to identify and reduce voice misuse to achieve the optimal voice. But complete resolution may not be possible in all patients after voice therapy. Furthermore, some patients with voice-related occupations, voice rest and voice therapy are sometimes difficult, which makes it hard to carry out the treatment. When conservative therapy is ineffective, laryngeal microsurgery can be performed under general anesthesia. However, potential complications following laryngeal suspension and violation of the layered structure of the vocal fold during surgery should be considered before surgery. In recent decades, emerging literatures have demonstrated the potential usefulness of vocal fold steroid injection as an alternative treatment option for benign vocal fold lesions. The most advantageous feature of vocal fold steroid injection is the maintenance of regional anti-inflammatory effects while preventing the potential systemic adverse effects of the steroid. Many non-surgical treatment methods can be conducted using different approaches in the office setting. It can be applied as an alternative treatment modality for the management of various benign vocal fold lesions.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.56-61
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• 2007

Introduction: Actually classification of classic singers' voice depends on habitual judgment by voice teachers or voice trainer referring to vocal timbre, vocal range and vocal quality. Such judgments, however, may turn out to be incorrect because they are based on subjective opinions. Therefore, more objective methodology is required. Method: Foreign dissertations searched through Pub Med, along with foreign and domestic journals, were reviewed regard ing how singers' voice has been categorized. Results: Vocal range, vocal timbre, voice quality, fundamental frequency of habitual speaking, length of vocal tract, the length from cricoid cartilage to thyroid cartilage's thyroid notch and length of vocal fold, tone of passaggio as well as traditional approaches such as perceptual judgment used by professional singers have been used for categorize the voice classification. Conclusion: To optimize categorizing singers' voice, vocal range, vocal timbre, voice quality, fundamental frequency of habitual speaking, length of vocal tract, the length from cricoid cartilage to thyroid cartilage's thyroid notch and length of vocal fold, tone of passaggio may be totally recommended.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.2
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• pp.161-166
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• 2000

Background and Objectives : Vocal fold hemorrhage occur by blood accumulation in Reinke's space by vocal trauma. It is mostly asymptomatic, but in some cases it may cause severe dysphonia. It is often seen in patients who use their voice professionally. However, recent changes of life style affected the phonation in general population. We studied to know what are the causes and what are the major factors to affect the vocal fold hemorrhages. Materials and Methods : 19 subjects were evaluated by using of questionaire and laryngoscopic examinations. We evaluated the factors to lead the change in voice directly, underlying causes, occupations and laryngeal findings. Results : The direct causes of the vocal fold hemorrhages were clearing throat, talking, coughing and singing. Reflux laryngitis and upper respiratory infection were the underlying diseases. Vocal fold hemorrhages were developed during the menstruation in 5 patients. Accompanying functional voice disorders were seen in 13 patients, such as, vocal fold nodule, nodule with varix, vocal polyp, Reinke's edema. Patients with reflux laryngitis had the habits of clearing throat as the direct cause of the vocal fold hemorrhages and had hyperkinetic functional voice disorders. Voice abuse was the direct cause of the vocal fold hemorrhages in patients who was in the period of the menstruation. The most common site of the hemorrhage was at the membranous portion of the vocal folds. Conclusions : Authors thought the forceful laryngeal activity was the cause of the vocal fold hemorrhages. And reflux laryngitis and menstruation was the risk factors of the vocal fold hemorrhages.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.6.2-6
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• 1983

The clinical study of 108 laryngeal mass was observed in our E.N.T. department, and classified clinically and pathologically as below. 1) Among total case of 108 Vocal nodule is 28 (26 %) Vocal polyp is 46 (42.5 %) Laryngeal papilloma is 6 (5.5 %) Laryngeal tuberculosis is 4 (4%) Laryngeal cancer is 24 (22%) 2) The sex ratio of male to female is 5 : 7 in vocal nodule 11 : 12 in vocal polyp 1 : 1 in laryngeal papilloma 3 : 1 in laryngeal tuberculosis 5 : 1 in laryngeal cancer 3) The age distribution is fourth, fifth decade in vocal nodule is fifth, fourth decade in vocal polyp is first decade in laryngeal papilloma is third and seventh decade in laryngeal tuberculosis is sixth and seventh decade in laryngeal cancer 4) The location of mass is between the anterior 1/3 and middle 1/3 of vocal cord in vocal nodule, polyp and papilloma middle 1/3 and posterior 1/3 in laryngeal tuberculosis and glottic (50%), supraglottic (42%), infraglottic (8%) in laryngeal cancer 5) The side of lesion is bilateral in vocal nodule and papilloma, the ratio of right to left is 2 : 3 in vocal polyp 6) The size is 1-2mm in vocal nodule and papilloma, 3-5mm in vocal polyp more than 10mm in laryngeal tuberculosis and laryngeal cancer 7) The duration of symptom is within 1 years in vocal nodule and vocal polyp and laryngeal papilloma, 1-several years in laryngeal tuberculosis and laryngeal cancer 8) The most frequent symptom was hoarseness 9) All laryngeal cancer was sguamous cell carcinoma