• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.2
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• pp.94-97
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• 2003

Background and Objectives : Bowing of the vocal fold, a bowed edge of the vocal fold results from various disorder causes glottic incompetence resulting in voice disorders. The results of treatment were not satisfactory even though a variety of methods of treatment were applied. The goal of this study is to evaluate of efficacy of the non-surgical, voice therapy in patients with vocal fold bowing. Materials and Method : Twenty two patients of vocal fold bowing not resulting from vocal fold palsy and sulcus vocalis were analyzed. After voice therapy and medical treatment, parameters of perceptual, acoustic, aerodynamic analysis and stroboscopic findings were compared those of pretreatment results. Results and Conclusion : Jitter, shimmer and maximal phonation time were significantly improved and subjective satisfaction was improved in 73% of patients. In the videostroboscopic examination, vocal fold gap was decreased in 27% of patents. The result of this study indicates that voice therapy alone has effect in treatment of vocal fold bowing. Voice therapy is one of the mainstay of treatment of vocal fold bowing.

• Phonetics and Speech Sciences
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• v.1 no.2
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• pp.37-42
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• 2009

The purpose of the present study was to determine the effect of the management program known as vocal function exercise (VFE) on voice quality. Typical VFE was modified and applied to patients with vocal nodules by controlling intensity of voice and relieving the vocal fold to solve hyperfunctional problems in VFE. Eight female subjects aged between 28 and 54 who had been diagnosed with vocal nodules took part in the study. The patients performed VFEs once a week for eight weeks. Vocal function exercises consist of voice hygiene, respiratory training, phonation training, and glide training. The subjects' voices were analyzed pre and post therapy on the aspects of acoustics, maximum phonation time (MPT), GRBAS, and voice handicap index (VHI). As a result, it was found that fundamental frequency ($F_o$) was significant increased, shimmer decreased remarkably and that noise to harmonic ratio (NHR) lowered obviously in the acoustic parameter. In addition, MPT was increased significantly. The scale of GRBAS indicated significant improvement in grade, roughness, and strained voice. VHI indicated significant improvement in an emotional part. In conclusion, VFE was effective in improving voice quality for patients with vocal nodules.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.83-93
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• 2013

Vocal hygiene education is an indirect training approach to improve vocal function by educating all facets of optimal vocal health. Satisfaction levels of participants might be an important component of this indirect therapy for voice disorders. The authors aimed to investigate the satisfaction levels of vocal hygiene education in 51 patients with voice problems. We classified voice disorders of the participants according to three etiological categories (subgroups): organic, neurogenic, and functional. The survey consisted of three parts: 1) a condition of vocal hygiene education, 2) a degree of satisfaction of the present education, and 3) a request for future education. Participants responded to each item of the survey using a five-point Likert scale of 1 to 5 (1 being not at all and 5 being extremely). They also wrote down personal comments of improvement. Participants scored the vocal hygiene education offered by the speech-language pathologists between '3' and '4'. Specifically, the participants were highly satisfied with the specific and comprehensible explanation/instruction given by their speech-language pathologists. However, they were less satisfied with the tuition fee for the therapy sessions. Vocal hygiene education is offered individually to people in a clinical setting. Our results support the notion that vocal hygiene education can be an integral aspect of the treatment of voice problems in most cases.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.1
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• pp.17-23
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• 1999

Vocal hyperfunction is considered to be the most significant characteristic in larynx disorders which is found among many patients presenting hoarseness Primarily as chief complaint. In Pusan National University Hospital, we executed the voice therapy to 28 patients being 17 female and 11 male patients who visited the Voice ＆ Speech Therapy Clinic, due to the voice disorder, and then compared and analysed the voice before and after its therapy using acoustic and aerodynamic test. The obtained results were as follows. In the analysis by the local findings, it was improved to 88% in the patients of vocal nodule, 75% in mutational falsetto, 75% in the functional dysphonia, 75% in the vocal cord palsy, 50% in the vocal polyp and 50% in dysphonia plica ventricularis. For the acoustic analysis, Fo, litter, Shimmer and NHR were measured. In the patients of mutational falsetto, Fo, Jitter and NHR were shown to be improved significantly and in the patients of vocal nodule, Shimmer was shown to be improved significantly. In the patients of vocal polyp, Fo was significantly improved. In the patients of vocal cord palsy in litter and NHH were significantly improved. In the patients of dysphonia plica ventricularis, Shimmer and NHR were significantly improved and the patients of functional dysphonia were more improved in Fo, litter and Shimmer. For the aerodynamic analysis, MPT was measured. In particular, it was shown to be improved significantly in the patients of vocal nodule, improved in the vocal polyp, vocal cord palsy, functional dysphonia patients.

• Phonetics and Speech Sciences
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• v.9 no.4
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• pp.99-106
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• 2017

Clinical data about vocal nodules have seldom been reported, even though vocal nodules are commonly diagnosed in outpatient speech and voice clinic. This study aims to investigate clinical characteristics of the patients who are diagnosed with vocal nodules. This study analyzed the data for 10 years from the 319 patients diagnosed with vocal nodules (45 males and 274 females with the mean age of 39.4 ranging from 2 to 83) in terms of gender, age, occupation, voice change initiation pattern, change with time, throat clearing, smoking history, type of voice abuse, acoustic analysis, maximum phonation time, GRBAS, and VHI. Thirteen patients (4.08%) had unilateral vocal nodule and 306 patients (95.9%) had bilateral vocal nodule, the majority of which had a pattern of asymmetry (73.9%). The glottal closure pattern was hourglass in 72.1% of patients, posterior chink in 17.9% of patients, and irregular in 7.9% of patients. The most common occupational category was professional voice users (43.4%). The voice abuse pattern included excessive talking in 96 patients (76.8%), loud voice in 78 (62.4%) patients, and excessive singing in 17 patients (21.6%). The patients showed worse scores in G, B, and S than in R and A for the GRBAS evaluation. The most recommended treatment for vocal nodules was voice therapy. The current clinical data will be helpful for treatment planning for the patients of vocal nodule.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.21-24
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• 2008

The present study numerically investigates the glottal airflow characteristics as well as acoustic features of phonation fully coupled with dynamic behavior of vocal folds. The vocal folds are described by a low-dimensional body-covered model characterized by bio-mechanical parameters such as glottal width, vocal folds stiffness, and subglottal pressure. The flow in the vocal tract is modeled as an incompressible, axisymmetric form of the Navier-Stokes equations (INS), while the acoustic field is predicted by the linearized perturbed compressible equations (LPCE). The computed result shows that a two-mass model of vocal folds is sufficient to reproduce temporal variations in oral airflow and glottis motion produced by female speakers. It is also found that i) the glottal width has a significant effect on the amplitude of glottal flow, and thus on the amplitude of acoustic wave in the vocal tract, ii) the vocal fold tension is the main control parameter for the fundamental frequency of phonation, iii) the subglottal pressure plays an appreciable role on reproduction of the self-sustained oscillation of vocal folds, and iv) the strength of pulsating airflow and vortical structures are primarily affected by glottal width and subglottal pressure, and are closely related to pitch, loudness, and voice quality. Finally, more comprehensive explanation about the difference between one- and two-mass models is presented with discussion of effectiveness of vocal folds oscillation and voice quality.

• Speech Sciences
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• v.3
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• pp.83-92
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• 1998

Vowels are classified by vocal tract shapes. These shapes form constriction points along the tract, which have an influence on such vocal tract resonance as $F_l,\;F_2,\;F_3$, and so on. This study reviews the perturbation theory of the tract and determines the corresponding formant frequencies from modified vocal tracts using vocal tract area function. Then, formant variation is observed from the theory. Finally, each set of $F_l,\;F_2,\;and\;F_3$ frequency is input to a speech synthesis software to make a vowel sound. Auditory impression of each sound without any modification of its vocal tract shape is almost the same as the corresponding phonetic symbol. Formant frequencies of $F_l,\;F_2,\;F_3$ vary according to the perturbation theory. Generally, constriction along the node causes formant values to decrease while constriction along the anti-node cause it to increase. Vocal tracts modified by more than $3\;cm^2$ change vowel qualities of /a/ and /i/ into those of f /v/ and /$\varepsilon$/, respectively. This study will be helpful in simulating sounds from modified vocal tracts before any operation. Further studies are desirable to compare vocal tract shapes of various languages and their sounds together.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.1
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• pp.71-78
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• 1998

Type Ⅰ thyuroplasty in conjunction with arytenoid adduction is one of the excellent techniques in the treatment of unilateral vocal fold paralysis. But perioperative objective evaluation of the patients is difficult. With the development of the videostroboscopy and image analysis program, we could quantify the Glottal Area Waveform(GAW) in patients with unilateral vocal fold paralysis and investigated the relationship between the glottal area and aerodynamic and acoustic parameters. Eight female patients who were performed type Ⅰ thyroplasty in conjunction with arytenoid adduction and 5 females with normal vocal function were involved in this study. Preoperative and postoperative videostroboscopy and vocal function study wire performed. GAW was analysed quantitatively with image analysis program (Kay Stroboscope Image analysis, KSIP) Peak Glottal Area(PGA), Baseline Offset(BO), and Closing Phase(CP) were increased in patients with unilateral vocal fold paralysis and they were reduced after the operation. Mean flow Rate (MFR) was well correlated with the PGA in normal control group and unilateral vocal fold paralysis patients. Noise to harmonic ratio(NHR) was correlated with PGA only in preoperative unilateral vocal fold paralysis patients. In conclusion quantitative measurement of the GAW is useful method in evaluation of unilateral vocal f31d paralysis patients.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.21 no.1
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• pp.27-31
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• 2010

Mild vocal fold hypomobility is a common finding of which clinical significance is incompletely understood. Recently, electrophysiologic investigations have shown that vocal fold hypomobility is a continuum of neurogenic dysfunction ; partial denervation (paresis), complete denervation (paralysis), and variable degrees and patterns of reinnervation. Despite a sound pathophysiological basis for its existence, interest in and acceptance of the diagnosis of vocal fold paresis is relatively recent. Vocal fold paresis may be a relatively common and often overlooked condition that can be difficult to diagnose since laryngoscopy does not reliably distinguish innocent laryngeal asymmetry from hypomobility caused by paresis. Although not entirely free from error, laryngeal electromyography seems to hold more promise as a means of reliable diagnosis than laryngoscopy, and should be employed systematically in the evaluation of suspected paresis. The means to help most patients with paresis already exists in the repertoire of interventions developed to treat paralysis. However, since the vocal fold retains substantial movement, more conservative treatment strategy is recommended as a first line of treatment. The authors reviewed the representative reports of vocal fold paresis and summarized the controversies and consensus regarding the vocal fold paresis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.6
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• pp.1126-1130
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• 2010

Speech production can be viewed as a filtering operation in which a sound source excites a vocal tract filter. The vocal tract is modeled as a chain of cylinders of varying cross-sectional area in linear prediction acoustic tube modeling. In this modeling the most common implementation assumes equal length of tube sections. Therefore, to model complex vocal tract shapes, a large number of tube sections are needed. This paper proposes a new vocal tract model with unfixed sectionlengths, which uses the reduced lattice filter for modeling the vocal tract. This model transforms the lattice filter to reduced structure and the Burg algorithm to modified version. When the conventional and the proposed models are implemented with the same order of linear prediction analysis, the proposed model can produce more accurate results than the conventional one. To implement a system within similar accuracy level, it may be possible to reduce the stages of the lattice filter structure. The proposed model produces the more similar vocal tract shape than the conventional one.