• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.2
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• pp.121-125
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• 2001

Singing requires exquisite coordination between the respiratory and phonatory system to efficiently control glottal airflow. Respiratory function and vocal aerodynamics were investigated in six female professional sopranos and in six female subjects without vocal training. All sopranos had more than 15 years of formal classic vocal training. Pulmonary function test data on simple pulmonary function, flow volume curve, static lung volumes, maximum inspiratory pressure(MIP), and maximum expiratory pressure(MEP) were obtained from all subjects. Vocal aerodynamic studies of maximum phonation time(MPT), phonation quotient, and mean glottal flow rates (MFR) were also measured in all subjects. Simple pulmonary function in professional sopranos was generally the same as that of other female subjects without vocal training. However, MIP and MEP showing respiratory muscle forces were significantly elevated in professional sopranos, compared to those of other female subjects without vocal training. Maximum phonation times and phonation quotient in sopranos are longer than those of other female subjects even though there were no differences in simple pulmonary function. High-pitched tones were made with significantly higher mean glottal flow rates(GFR) in normal subjects than low-pitched tones, whereas no changes in GFR were found in sopranos. The result indicated that sopranos demonstrated significant improvements in aerodynamic measures of GFR, maximum phonation time, suggesting an increase in glottal efficiency.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.2
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• pp.133-139
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• 2001

Background and Objectives : There are so many methods to investigate the causes of voice disorders. However, they were almost invasive or non-physiologic methods. And none of them showed the laryngeal movements. Phonation pharyngogram is non-invasive method to see the laryngeal movement directly. Authors studied to evaluate the availability of phonation pharyngogram in laryngeal nodule. Materials and Methods : 30 laryngeal nodules and 10 control groups were evaluated. Acoustic analysis and maximum phonation time were measured and pharyngogram was taken during sustaining /a/ phonation immediately after swallowing the barium. We measured the width of hypopharyngeal wall, shape of hypopharyngeal wall and pyriform sinus apex, level difference between both true vocal folds, angle of subglottis, location of true vocal folds, elevated distance of vocal folds and shape of c-spine. Results : Jitter, Shimmer of laryngeal nodule were higher than control group and maximum phonation time was shorter in laryngeal nodule. There was a significance in width of hypopharyngeal wall, shape of pyriform sinus apex, level difference between both true vocal folds, elevated distance of vocal folds and shape of c-spine. Conclusions : Authors knew that there were differences when we used the phonation pharyngogram between normal group and laryngeal nodule group.

• Phonetics and Speech Sciences
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• v.8 no.3
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• pp.39-49
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• 2016

The present study examined the change of aerodynamic features after laryngomicrosurgery in patients with vocal polyps. Aerodynamic evaluation was performed in thirty-nine patients (15 males and 24 females) one week before surgery and four weeks after surgery. Evaluation protocols of vital capacity, maximum sustained phonation(MXPH), and voicing efficiency(VOFT) were used to collect 29 phonatory aerodynamic measures, requiring voice with a comfortable pitch and loudness. Statistically significant changes were found for phonation time and airflow values in the MXPH protocol, while changes were also found for airflow values, subglottal pressure values and acoustic resistance values in the VOFT protocol. Although phonation time was increased in both male and female patients, gender-dependent changes were found in airflow measurements. Men's phonation time increased with no difference in airflow rate, but women's phonation time increased with decreased airflow rate and lower subglottal pressure. The changes of aerodynamic features may be affected by women's self-perceived change for vocal attitude, which was reducing sense of vocal effort after surgery.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.6 no.1
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• pp.9-15
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• 1995

Bowing of the vocal cords may be due to aging. atrophy. bilateral superior laryngeal nerve paralysis. injudicious vocal cord surgery, of an idiopathic cause. The bowing usually produces a dysphonia characterized by breathiness due to air escape : however, it can produce aphonia. This report reviews vocal function after surgical correction of bowing of the vocal cords for diagnosis and management. The vocal function of 13 patients with sulcus vocalis and 12 patients with vocal cord atrophy was evaluated with the use of a test battery of multidimensional evaluation items. The voice was improved postoperatively in most patients. The voice improvement was reflected objectively in maximum phonation time, mean air flow rate during phonation, stroboscopic findings. sound pressure level range and fundamental frequency range of phonation, and results of acoustic analyses of tape-recorded voice. The vocal function after surgical correction of the sulcus vocalis and vocal cord atrophy was improved postoperatively in most patient, but the results were not satisfactory.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.17 no.1
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• pp.14-16
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• 2006

Background and Objectives: The purpose of this study is to investigate the change of vocal tract length according to the level of the pitch by the singers. Materials and Methods: Fifteen tenors were asked to produce successive /a/ sound in G4(382Hz) for the head register, C3(131Hz) for the chest register and usual speaking sound. The control group consisted of 15 males of an similar age who are not professional singers. The length of vocal tract was calculated by applying the formula of Fn=(2n-1) c/4L(F : formant frequency, c : the speed of sound in the vocal tract(350m/sec), L : length of vocal tract, $n=1,2,3,4,{\ldots}{\infty}$). Results: In singer's group, there showed no significant statistical difference of length among head and chest register and usual speaking sound. However in the control group, there showed statistically significant difference of length. Comparison of the absolute difference in the length of vocal tract by changing level of pitch in phonation, between the control group and the singers group. Changing from G4 phonation to C3 phonation and C3 phonation to usual speaking sound showed statistically difference of vocal tract length was less in the singers group than the control group. Conclusion: The change of vocal tract length, in either speaking or singing, was less in singers than the control group. We could assume that the singers maintain their larynx position constantly throughout the pitch range when phonation.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.8.3-8
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• 1979

Dohne (1944) has studied the consumption of air during phonation in patients with dysphonia and Arnold (1955, 1958) reported that the maximum phonation time is frequently reduced to a few seconds in paralytic dysphonia. Also, Nishikawa investigated the relation among the vital capacity, maxium phonation time, caculated mean flow rate and various vocal characteristics in patients with hoarseness. Authors have studied the aerodynamic characteristics of the vocal tract in the following aspects, using 9 L. Respirometer made in Collins Inc.; 1. Maximum phonation time 2. Maximum phonation volume 3. Mean flow rate 4. Vocal velocity index

• 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.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.23-27
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• 2006

Purpose: There are a few case reports on asymmetric vocal cord uptake on FDG-PET in patients with unilateral vocal cord paralysis, which could be a potential pitfall in the interpretation of FDG-PET images. We evaluated the metabolic activity of laryngeal muscles of patients with unilateral vocal cord paralysis in comparison to normal controls during both speech and silence. Methods: Eleven patients with unilateral vocal cord palsy (thyroldectomy=7, lung cancer=1, others=3) and 12 normal controls underwent FDG-PET with usual protocol. They were divided into two groups respectively; one group read books aloud for 20 minutes (phonation group) and the other kept silence (non-phonation groups) after FDG injection. Recent neck CT scan were co-registered with FDG-PET to produce PET-CT fusion images to elaborate small laryngeal muscles. Results: In patients with unilateral vocal cord palsy, contralateral non-paralyzed vocal cord showed hypermetabolism mainly on thyroarytenoid muscle, more intensely with phonation group ($SUV=5.88{\pm}2.65$) than with non-phonation group ($SUV=2.30{\pm}0.39$). Normal control subjects showed hypermetabolism ($3.68{\pm}0.96$) in interarytenoid muscle and symmetric mild hypermetabolism in both lateral cricoarytenoid muscles in only phonation group. Conclusion: FDG-PET with fusion images using CT scan in patients with unilateral vocal cord paralysis showed hypermetabolism of contralateral non-paralyzed thyroarytenoid muscle, suggesting compensatory action during phonation. Phonation durung FDG PET study enhanced FDG uptake on different laryngeal muscles between patients with unilateral vocal cord paralysis and normal subjects.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.1
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• pp.12-16
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• 1999

Background and Objectives : The common cause of voice disorders may be bad habits of phonation. faulty vocal habits might aggravate the voice disorder or make the dysphonia. Authors thought the analysis of faulty vocal habits might help to evaluate the causes and to choose the treatment methods in patients with dysphonia. Authors studied to evaluate which vocal habits were used in patients with dysphonia. Materials and Methods : Patients with dysphonia(N= 32) and person without dysphonia(N=20) were evaluated through pre-evaluation test by otolaryngologist and SLP. All subjects were evaluated accordingly Posture of body, expansion of cervical vein, excessive movements of thyroide prominence, position of tongue, tension of lower lip, tension of jaw, breathing pattern related with phonation. Results : In dysphonia group, we found 23 cases with tension of jaw, 15 cases with expansion of cervical vein, 7 cases with bad position of tongue, 3 cases with excessive movement of thyroid prominence and a lot of cases with bad breathing Pattern on Phonation. In control group, only 3 cases with bad position of tongue, 2 cases with tension of lower lip, 1 case with tension of jaw were found. Conclusions : More faulty vocal habits were found in dysphonia group. Authors thought faulty vocal habits could be the cause of dysphonia and aggravate the dysphonia and the control of vocal habits would be very important in patients with dysphonia.

• Phonetics and Speech Sciences
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• v.9 no.3
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• pp.75-83
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• 2017

The purpose of this study is to find clues to the risk of voice disorders in soprano students. The subjects of the study were 17 soprano students and 18 general students (women). The phonation of vowels /a/, /i/, and /u/ with C4 and F4 notes in each group were recorded. Then, only soprano students were made to record their classical vocalization containing vibrato. Formant, formant energy, bandwidth, VAI (vowel area index), VSA (vowel space area) and L/H ratio were analyzed. There was significant difference in F3 such that the singers' note was measured around 3 kHz which seems to be 400 Hz higher than one from general students. But, There was no significant difference in L/H ratio between soprano student and the general student. There was a significant difference in F3 in the comparison of the soprano students' two vocalization methods. Classical vocalization was measured at 200Hz higher than sustained phonation in F3. Vocal tract adjustment was made and vowel space changed, but there was no significant difference in F3 energy, which is the index of singers' formant according to the phonation method. The L/H ratio, which can be a direct indicator of vocal effort, has no difference in phonation method and is lowered in all phonation methods as the pitch increases. C4 and F4 pitches are lower than the singing range of the soprano. When the pitch changes, vocal effort increases like a general student which will be an indicator of the risk of vocalization. This will be a clue to the vocalization of the immature soprano student.