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Zhaoyan Zhang - One of the best experts on this subject based on the ideXlab platform.
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a computational study of vocal fold dehydration during Phonation
IEEE Transactions on Biomedical Engineering, 2017Co-Authors: Zhaoyan ZhangAbstract:While vocal fold dehydration is often considered an important factor contributing to vocal fatigue, it still remains unclear whether vocal fold vibration alone is able to induce severe dehydration that has a noticeable effect on Phonation and perceived vocal effort. A three-dimensional model was developed to investigate vocal fold systemic dehydration and surface dehydration during Phonation. Based on the linear poroelastic theory, the model considered water resupply from blood vessels through the lateral boundary, water movement within the vocal folds, water exchange between the vocal folds and the surface liquid layer through the epithelium, and surface fluid accumulation and discharge to the glottal airway. Parametric studies were conducted to investigate water loss within the vocal folds and from the surface after a 5-min sustained Phonation under different permeability and vibration conditions. The results showed that the dehydration generally increased with increasing vibration amplitude, increasing epithelial permeability, and reduced water resupply. With adequate water resupply, a large-amplitude vibration can induce an overall systemic dehydration as high as 3%. The distribution of water loss within the vocal folds was non-uniform, and a local dehydration higher than 5% was observed even under conditions of a low overall systemic dehydration (<1%). Such high level of water loss may severely affect tissue properties, muscular functions, and Phonations characteristics. In contrast, water loss of the surface liquid layer was generally an order of magnitude higher than water loss inside the vocal folds, indicating that the surface dehydration level is likely not a good indicator of the systemic dehydration.
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a computational study of vocal fold dehydration during Phonation
Journal of the Acoustical Society of America, 2016Co-Authors: Zhaoyan ZhangAbstract:Vocal fold dehydration during Phonation is investigated in a continuum model of the vocal folds. Based on the linear poroelastic theory, the model simulates water movement inside the vocal folds during Phonation, water exchange between the vocal folds and the surface mucosal layer through the epithelium layer, surface water accumulation and loss to the glottal airway, and water resupply from blood through the lateral boundary. Parametric studies are conducted to investigate water loss within the vocal folds after 5 minutes of Phonation at different voice conditions. The results show that with normal water resupply from the blood, water loss within the vocal folds increases with greater vibration amplitude and higher epithelium permeability. At very large vibration amplitudes, the water loss within the vocal folds can be as high as 3%, which may severely affect body functions and possibly Phonation characteristics and vocal effort. Reduced water resupply from blood further increases the degree of dehydrati...
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respiratory laryngeal coordination in airflow conservation and reduction of respiratory effort of Phonation
Journal of Voice, 2016Co-Authors: Zhaoyan ZhangAbstract:Summary Objective This study evaluates the need of airflow conservation and the effect of glottal resistance on respiratory effort of Phonation under different Phonation conditions. Methods A computational model of the pressure–volume–flow relationship of the respiratory system is developed. Results Simulations show that increasing the glottal resistance reduces the glottal airflow and allows Phonation to be sustained for a longer breath group duration. For a given breath group duration, the reduced airflow also allows Phonation to be sustained within a narrow range of lung volumes, thus lowering the overall respiratory effort. Conclusions This study shows that for breath group durations and subglottal pressures typical of normal conversational speech, airflow conservation or maintaining "effortless" respiratory support does not provide a stricter requirement on the glottal resistance than that required for initiating Phonation. However, the need for airflow conservation and respiratory effort reduction becomes relevant when the target subglottal pressure and breath group duration increase as in prolonged speech or singing or in conditions of weakened pulmonary function. In those conditions, the glottal resistance is expected to increase proportionally with increasing subglottal pressure to conserve airflow consumption and reduce respiratory effort.
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experimental validation of a three dimensional reduced order continuum model of Phonation
Journal of the Acoustical Society of America, 2016Co-Authors: Mehrdad H Farahani, Zhaoyan ZhangAbstract:Due to the complex nature of the Phonation process, a one-dimensional (1D) glottal flow description is often used in current Phonation models. Although widely used in voice research, these 1D flow-based Phonation models have not been rigorously validated against experiments. In this study, a 1D glottal flow model is coupled with a three-dimensional nonlinear continuum model of the vocal fold and its predictions are compared to physical model experiments. The results show that the 1D flow-based model is able to predict the Phonation threshold pressure and onset frequency within reasonable accuracy and to reproduce major vibratory features observed in the experiments.
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Phonation threshold pressure and onset frequency in a two layer physical model of the vocal folds
Journal of the Acoustical Society of America, 2011Co-Authors: Abie H Mendelsohn, Zhaoyan ZhangAbstract:The influence of vocal fold geometry and stiffness on Phonation onset was experimentally investigated using a body-cover physical model of the vocal folds. Results showed that a lower Phonation threshold pressure and Phonation onset frequency can be achieved by reducing body-layer or cover-layer stiffness, reducing medial surface thickness, or increasing cover-layer depth. Increasing body-layer stiffness also restricted vocal fold motion to the cover layer and reduced prephonatory glottal opening. Excitation of anterior–posterior modes was also observed, particularly for large values of the body-cover stiffness ratio. The results of this study were also discussed in relation to previous theoretical and experimental studies.
Jack J Jiang - One of the best experts on this subject based on the ideXlab platform.
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the therapeutic effects of straw Phonation on vocal fatigue
Laryngoscope, 2020Co-Authors: Jing Kang, Chao Xue, Yi Zhang, Zhewei Lou, Austin Scholp, Jack J JiangAbstract:OBJECTIVES Straw Phonation has been investigated for its vocal warm-up effects on healthy populations and therapeutic effects on voice patients. The purpose of this article was to determine whether it is beneficial for vocal fatigue. STUDY DESIGN Prospective cohort study METHODS: Twenty-five healthy participants were recruited into 1-hour vocal loading tasks followed by 10-minute vocal rest or straw Phonation on 2 different days. Various parameters including Phonation threshold pressure (PTP), mean airflow, closed quotient (CQ), current speaking effort level (EFFT), and laryngeal discomfort (DISC) were acquired at baseline, after vocal load, and after the intervention. RESULTS Increased PTP, EFFT, and DISC were observed after vocal load. Decreased PTP, EFFT, and DISC were then acquired after both vocal rest or straw Phonation. More significant improvements were obtained in straw Phonation when compared with vocal rest. Additionally, significantly increased mean flow and decreased CQ were obtained after straw Phonation when compared to vocal rest. CONCLUSIONS Straw Phonation has the potential to adjust aerodynamics within the vocal tract leading to improved vocal efficiency, optimized vibration mode, and attenuated vocal fatigue. This study provided a promising treatment for vocal fatigue that could have wide clinical relevance to voice users with high voice demands. LEVEL OF EVIDENCE 4 Laryngoscope, 2020.
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lingering effects of straw Phonation exercises on aerodynamic electroglottographic and acoustic parameters
Journal of Voice, 2019Co-Authors: Jing Kang, Chao Xue, David Piotrowski, Ting Gong, Yi Zhang, Jack J JiangAbstract:Summary Objective This study aimed to investigate the duration of straw Phonation effects using aerodynamic, electroglottographic, and acoustic metrics. Methods Twenty-four participants were recruited to perform both a 5-minute and a 10-minute straw Phonation exercise. Upon completion of the exercises, Phonation threshold pressure (PTP), mean airflow, contact quotient, fundamental frequency, jitter, shimmer, and noise-to-harmonics ratio were measured over a 20-minute time frame. Parameters were measured before the intervention (baseline), immediately after the intervention (m0), 5 minutes (m5), 10 minutes (m10), 15 minutes (m15), and 20 minutes (m20) after the intervention. Results PTP significantly decreased immediately after 5 minutes of straw Phonation and returned to initial state within 5 minutes. PTP remained decreased over 5 minutes after 10 minutes of straw Phonation. Mean airflow increased immediately after both 5 minutes and 10 minutes of straw Phonations and remained improved for 20 minutes. No significant changes were obtained for contact quotient and acoustic parameters over the intervention period. Conclusions The results extended our knowledge of proper clinical application of straw Phonation regarding the duration of exercise. This study confirmed that 10 minutes of straw Phonation lead to optimal and relatively continuous effects in PTP and mean airflow. Although straw Phonation did show lingering effects in aerodynamics, repeated practices were recommended to obtain optimum and therapeutic effects.
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effects of straw Phonation through tubes of varied lengths on sustained vowels in normal voiced participants
Journal of Voice, 2017Co-Authors: Randal D Mills, Shawna Rivedal, Colten Demorett, Grace Maples, Jack J JiangAbstract:Summary Objective To examine the immediate effects of straw Phonation exercises in normal subjects while altering the effective length of the vocal tract. Study Design A nonrandomized comparison of semi-occluded vocal tract length during straw Phonation exercises was carried out. Methods Oral pressure, mean airflow, aerodynamic resistance, and contact quotient were measured in 20 healthy subjects immediately before and after straw Phonation exercises. A short- and long-duration phonatory task was used to examine the voice parameters during semi-occluded vocal tract exercises. These tasks involved repeating a vocalization of the vowel /a/ through a tube. Each subject underwent the protocol using tubes of three different lengths (7.5 cm, 15 cm, and 30 cm) to allow for the effect of moving the outlet of the vocal tract distal to the mouth to be monitored. Results Oral pressure and aerodynamic resistance decreased significantly, contact quotient showed a decreasing trend, and airflow increased significantly in pre- and postmeasurements 15 minutes after a long-duration phonatory task. Short-duration tasks were found to have no effect on voice parameters. Conclusion The results present and validate a method to isolate the effect that the length of a semi-occluded vocal tract has during straw Phonation exercises.
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Phonation threshold flow measurements in normal and pathological Phonation
Laryngoscope, 2009Co-Authors: Peiyun Zhuang, Yi Zhang, Jack J Jiang, Alicia J Sprecher, Matthew R Hoffman, Marios Fourakis, Chun Sheng WeiAbstract:Objectives/Hypothesis: Phonation threshold flow (PTF) may provide a tool to assess laryngeal function and could differentiate between normal and pathological voices. Both polyps and nodules contribute to an increased PTF by creating an incomplete glottal closure and increased vocal fold mass and thickness. Study Design: Prospective study. Methods: The Kay Elemetrics Phonatory Aerodynamic System (PAS) (Kay Elemetrics Corp., Lincoln Park, NJ) was used to collect mean flow rate (MFR) and PTF measurements from 40 normal subjects, 21 patients with vocal fold nodules, and 23 patients with vocal fold polyps. Gender-based differences were assessed using a t test. The effect of vocal pathology on PTF and MFR was determined with an ANOVA. Diagnostic potential was evaluated using a receiver operation characteristics (ROC) analysis. Results: Both PTF (P = .047) and MFR (P = .008) were significantly affected by gender. Using a two-way ANOVA and correcting for gender differences, the influence of pathology on PTF was determined to be significant (P < .001). Post hoc tests found a significant difference between normal and polyp subjects (P < .001) but not normal and nodule subjects (P = .177) or nodule and polyp subjects (P = .246). ROC analysis found that PTF (area under the curve [AUC] = 0.691) and MFR (AUC = 0.684) had a similar diagnostic utility. Conclusions: PTF can be used to differentiate between normal and pathological voices. As a parameter that is experimentally sensitive to the biomechanical parameters providing its theoretical basis, it could be used clinically to analyze laryngeal functionality. Future research could focus on measuring PTF in other pathologies, such as paralysis or scarring, which would also affect the effort required to produce voice. Laryngoscope, 2009
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the Phonation critical condition in rectangular glottis with wide prephonatory gaps
Journal of the Acoustical Society of America, 2008Co-Authors: Jack J JiangAbstract:The effect of the pressure recovery at glottal exit is introduced to modify the one-mass model. Using the modified one-mass model, the Phonation critical condition, including Phonation threshold pressure and Phonation threshold flow, is analyzed by using the small-amplitude oscillation theory. It is found that the Phonation threshold pressure is not sensitive to the change of the prephonatory glottal width at a wide glottal gap. This result agrees with previous experimental observations and suggests that the low slope of dependence of Phonation threshold pressure on prephonatory gap found by Chan and Titze [J. Acoust. Soc. Am. 119, 2351–2362 (2006)] could be a consequence of the pressure recovery effect at the glottal exit. In addition, it is predicted that the Phonation threshold flow is always significantly increased with the prephonatory gap even at a wide prephonatory glottal gap. Therefore, the Phonation threshold flow has an advantage in assessing the phonatory system at a wide prephonatory gap in c...
Bernard Rousseau - One of the best experts on this subject based on the ideXlab platform.
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Effects of Phonation time and magnitude dose on vocal fold epithelial genes, barrier integrity, and function
Laryngoscope, 2014Co-Authors: Tsuyoshi Kojima, Carla V. Valenzuela, Carolyn K. Novaleski, Mark Van Deusen, Joshua R. Mitchell, C. Gaelyn Garrett, M. Preeti Sivasankar, Bernard RousseauAbstract:Objectives/Hypothesis To investigate the effects of increasing time and magnitude doses of vibration exposure on transcription of the vocal fold's junctional proteins, structural alterations, and functional tissue outcomes. Study Design Animal study. Methods 100 New Zealand White breeder rabbits were studied. Dependent variables were measured in response to increasing time doses (30, 60, or 120 minutes) and magnitude doses (control, modal intensity, and raised intensity) of vibration exposure. Messenger RNA expression of occludin, zonula occluden-1 (ZO-1), E-cadherin, β-catenin, interleukin 1β, cyclooxygenase-2, transforming growth factor β-1, and fibronectin were measured. Tissue structural alterations were assessed using transmission electron microscopy (TEM). Transepithelial resistance was used to measure functional tissue outcomes. Results Occludin gene expression was downregulated in vocal folds exposed to 120-minute time doses of raised-intensity Phonation, relative to control, and modal-intensity Phonation. ZO-1 gene expression was upregulated following a 120-minute time dose of modal-intensity Phonation, compared to control, and downregulated after a 120-minute time dose of raised-intensity Phonation, compared to modal-intensity Phonation. E-cadherin gene expression was downregulated after a 120-minute time dose of raised-intensity Phonation, compared to control and modal-intensity Phonation. TEM revealed extensive desquamation of the stratified squamous epithelial cells with increasing time and magnitude doses of vibration exposure. A general observation of lower transepithelial resistance measures was made in tissues exposed to raised-intensity Phonation compared to all other groups. Conclusions This study provides evidence of vocal fold tissue responses to varying time and magnitude doses of vibration exposure. Level of Evidence NA Laryngoscope, 124:2770–2778, 2014
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raised intensity Phonation compromises vocal fold epithelial barrier integrity
Laryngoscope, 2011Co-Authors: Bernard Rousseau, Atsushi Suehiro, Nicholas Echemendia, M. Preeti SivasankarAbstract:Objectives/Hypothesis: We investigated the hypothesis that 30 minutes of raised intensity Phonation alters transcript levels of vocal fold intercellular tight junction proteins and disrupts the vocal fold epithelial barrier. Study Design: Prospective animal study. Methods: Eighteen New Zealand white breeder rabbits were randomly assigned to receive 30 minutes of raised intensity Phonation or approximation of the vocal folds without Phonation. Quantitative polymerase chain reaction (qPCR) was used to investigate transcript levels of the epithelial intercellular tight junction proteins, occludin and zonula occludin-1 (ZO-1), and the adherens junction proteins β-catenin and E-cadherin. Structural alterations to the vocal fold epithelium were further examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results: Mann-Whitney U revealed significantly decreased occludin (P = .016) and β-catenin (P = .016) gene expression from rabbits undergoing raised intensity Phonation compared with control. There were no significant differences in Z0-1 and E-cadherin gene expression between groups (P > .025). SEM revealed significant obliteration, desquamation, and evidence of microhole formation in rabbit vocal folds exposed to raised intensity Phonation compared with control, whereas TEM revealed dilated intercellular morphology between groups. Conclusions: Results provide support for the hypothesis that a transient episode of raised intensity Phonation alters transcript levels of vocal fold intercellular tight junction proteins and disrupts integrity of the epithelial barrier. The loss of barrier integrity may have significant consequences on epithelial defenses and compromise protection of the underlying mucosa from damage secondary to prolonged vibration exposure.
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Characterization of raised Phonation in an evoked rabbit Phonation model.
The Laryngoscope, 2009Co-Authors: Erik R. Swanson, Davood Abdollahian, Tsunehisa Ohno, David L. Zealear, Bernard RousseauAbstract:Objectives/Hypothesis: Our laboratory has developed an in vivo rabbit model to investigate the effects of Phonation on expression and turnover of the vocal fold extracellular matrix. As a logical outgrowth of this research to include phonotrauma in the present study, we investigated the hypothesis that an increase in airflow rate delivered to the glottis produces a change in glottal configuration and an increase in mean Phonation intensity. Study Design: Prospective animal study. Methods: Six New Zealand white breeder rabbits weighing 3 to 5 kg were used in this study. A rigid endoscope and camera were used to document glottal configuration. Acoustic signals of modal and raised Phonation were recorded and digitized. Two separate one-way repeated measures analysis of variance (ANOVA) tests were used to investigate within subject differences in Phonation intensity and fundamental frequency between modal and raised Phonation. Results: Phonation intensity was 54.19 dB SPL (6.21 standard deviations [SD]) during modal Phonation, and 60.31 dB SPL (5.68 SD) during raised Phonation. Endoscopic images revealed a convergent glottis, with greater separation of the vocal folds during raised Phonation. Results of ANOVA revealed a significant within subjects effect for Phonation intensity (P = .011). Pairwise comparisons revealed that Phonation intensity increased significantly during raised Phonation, compared to modal Phonation (P = .008). No differences in mean fundamental frequency were observed between Phonation conditions. Conclusions: Improved understanding of factors that control Phonation output in the in vivo rabbit model will result in improved capabilities to match Phonation dose across animals and provide immediate direction to future biochemical studies. Laryngoscope, 2009
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Characterization of Raised Phonation in an Evoked Rabbit Phonation Model
2009Co-Authors: Erik R. Swanson, Davood Abdollahian, Tsunehisa Ohno, David L. Zealear, Bernard RousseauAbstract:Objectives/Hypothesis: Our laboratory has developed an in vivo rabbit model to investigate the effects of Phonation on expression and turnover of the vocal fold extracellular matrix. As a logical outgrowth of this research to include phonotrauma in the present study, we investigated the hypothesis that an increase in airflow rate delivered to the glottis produces a change in glottal configuration and an increase in mean Phonation intensity. Study Design: Prospective animal study. Methods: Six New Zealand white breeder rabbits weighing 3 to 5 kg were used in this study. A rigid endoscope and camera were used to document glottal configuration. Acoustic signals of modal and raised Phonation were recorded and digitized. Two separate one-way repeated measures analysis of variance (ANOVA) tests were used to investigate within subject differences in Phonation intensity and fundamental frequency between modal and raised Phonation. Results: Phonation intensity was 54.19 dB SPL (6.21 standard deviations [SD]) during modal Phonation, and 60.31 dB SPL (5.68 SD) during raised Phonation. Endoscopic images revealed a convergent glottis, with greater separation of the vocal folds during raised Phonation. Results of ANOVA revealed a significant within subjects effect for Phonation intensity (P = .011). Pairwise comparisons revealed that Phonation intensity increased significantly during raised Phonation, compared to modal Phonation (P = .008). No differences in mean fundamental frequency were observed between Phonation conditions. Conclusions: Improved understanding of factors that control Phonation output in the in vivo rabbit model will result in improved capabilities to match Phonation dose across animals and provide immediate direction to future biochemical studies.
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experimentally induced Phonation increases matrix metalloproteinase 1 gene expression in normal rabbit vocal fold
Otolaryngology-Head and Neck Surgery, 2008Co-Authors: Bernard Rousseau, David L. Zealear, Lesley C French, Susan L Thibeault, Robert H OssoffAbstract:Objectives An in vivo rabbit model was used to study the effect of 3 hours of experimentally induced Phonation on messenger RNA expression of the normal vocal fold. Study Design Prospective; animal model. Subjects and Methods Ten rabbits received experimental Phonation for 3 hours, followed by 1 hour of recovery. A separate group of 5 rabbits served as no-Phonation controls. We measured messenger RNA expression of matrix metalloproteinase-1, MMP-9, and interleukin-1β using real-time reverse-transcribed polymerase chain reaction. Gene expression ratios from Phonation and control animals were assessed with the Mann-Whitney U test. Results Phonation (77 ± 3 dB; 429 ± 141 Hz) resulted in increased matrix metalloproteinase-1 gene expression from rabbits receiving experimental Phonation compared with controls, and a nonsignificant increase in matrix metalloproteinase-9 and interleukin-1β gene expression. Conclusion Matrix metalloproteinases play a role in maintaining tissue homeostasis. Investigation of cellular responses to experimental Phonation may provide insight into how matrix metalloproteinases and other extracellular matrices contribute to maintenance of the vocal fold and development of pathology.
Gerald S. Berke - One of the best experts on this subject based on the ideXlab platform.
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development of the ex vivo laryngeal model of Phonation
Laryngoscope, 2015Co-Authors: Scott N Howard, Abie H Mendelsohn, Gerald S. BerkeAbstract:© 2014 The American Laryngological, Rhinological and Otological Society, Inc. Objectives/Hypothesis The direct study of human Phonation is limited by the invasive and painful nature of human laryngeal neuromuscular manipulation. As a platform for the study of human Phonation, indirect models have been utilized for decades such as animal, cadaveric, and computational. We sought to develop a research method allowing direct scientific control of virtually living larynges to expand our ability to understand human Phonation. Study Design Canine and porcine models. Methods Nineteen canine larynges were surgically removed and reperfused with progressively adapting methodologies to create ex vivo Phonation. Results Full neuromuscular stimulation and Phonation were ultimately achieved in the ex vivo larynx. As compared with alternative perfusate solutions, heparinized whole blood was found to result in the most robust neuromuscular response. Modification of the reperfusion technique from a continuous flow to a pulsatile pump system resulted in dramatic increases in neuromuscular response and longevity of the organ. The experimental findings were repeated to demonstrate reliability of the ex vivo model. Conclusions The ex vivo larynx model is demonstrated to be a repeatable platform for phonatory research. The process of development has been comprehensively described in the present report. Although the described experimental model was designed for phonatory research, this model can be readily adapted for investigations of organ transplant preservation techniques, effects of organ ischemia, and neuromuscular reinnervation capabilities.
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Development of the ex vivo laryngeal model of Phonation - eScholarship
The Laryngoscope, 2015Co-Authors: Ns Howard, Abie H Mendelsohn, Gerald S. BerkeAbstract:© 2015 The American Laryngological, Rhinological and Otological Society, Inc. Objectives/Hypothesis: The direct study of human Phonation is limited by the invasive and painful nature of human laryngeal neuromuscular manipulation. As a platform for the study of human Phonation, indirect models have been utilized for decades such as animal, cadaveric, and computational. We sought to develop a research method allowing direct scientific control of virtually living larynges to expand our ability to understand human Phonation. Study Design: Canine and porcine models. Methods: Nineteen canine larynges were surgically removed and reperfused with progressively adapting methodologies to create ex vivo Phonation. Results: Full neuromuscular stimulation and Phonation were ultimately achieved in the ex vivo larynx. As compared with alternative perfusate solutions, heparinized whole blood was found to result in the most robust neuromuscular response. Modification of the reperfusion technique from a continuous flow to a pulsatile pump system resulted in dramatic increases in neuromuscular response and longevity of the organ. The experimental findings were repeated to demonstrate reliability of the ex vivo model. Conclusions: The ex vivo larynx model is demonstrated to be a repeatable platform for phonatory research. The process of development has been comprehensively described in the present report. Although the described experimental model was designed for phonatory research, this model can be readily adapted for investigations of organ transplant preservation techniques, effects of organ ischemia, and neuromuscular reinnervation capabilities.
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Ex vivo perfused larynx model of Phonation: preliminary study.
Annals of Otology Rhinology & Laryngology, 2007Co-Authors: Gerald S. Berke, David A. Berry, Juergen Neubauer, Dinesh K. ChhetriAbstract:Objectives: Although excised laryngeal models and physical models of the larynx are important in the study of laryngeal dynamics, they cannot be used to study the influence of neuromuscular contraction on vocal fold vibration, especially with regard to the thyroarytenoid muscle. Our aim was to develop an ex vivo larynx model of Phonation, and combine the benefits of the in vivo and excised laryngeal models to the ex vivo situation. Methods: Three canine larynges were surgically removed and perfused ex vivo with modified Krebs-Henseleit reperfusion solution. The laryngeal nerves were stimulated, and an assessment of neuromuscular viability, Phonation, and vocal fold vibration was made. Results: Neuromuscular stimulation, Phonation, and experimental manipulation were possible for several hours after the onset of ex vivo perfusion. Repeatable periodic Phonation in short bursts was achieved. Perfusion appears critical to maintain ex vivo viability, as adductory force was almost immediately lost upon cessation of ex vivo perfusion. Conclusions: The ex vivo larynx model has the potential to facilitate the measurement of glottal variables in a neuro-muscularly correct model. We propose that the further development of this laryngeal model may be useful in the study of laryngeal dynamics, particularly when invasive measurements, such as that of glottal exit flow, are required.
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a quantitative study of the medial surface dynamics of an in vivo canine vocal fold during Phonation
Laryngoscope, 2005Co-Authors: Michael Doellinger, David A. Berry, Gerald S. BerkeAbstract:Objectives/Hypothesis: The purpose of this study was to measure the medial surface dynamics of a canine vocal fold during Phonation. In particular, displacements, velocities, accelerations, and relative phase velocities of vocal fold fleshpoints were reported across the entire medial surface. Although the medial surface dynamics have a profound influence on voice production, such data are rare because of the inaccessibility of the vocal folds. Study Design: Medial surface dynamics were investigated during both normal and fry-like Phonation as a function of innervation to the recurrent laryngeal nerve for conditions of constant glottal airflow. Methods: An in vivo canine model was used. The larynx was dissected similar to methods described in previous excised hemilarynx experiments. Phonation was induced with artificial airflow and innervation to the recurrent laryngeal nerve. The recordings were obtained using a high-speed digital imaging system. Three dimensional coordinates were computed for fleshpoints along the entire medial surface. The trajectories of the fleshpoints were preprocessed using the method of Empirical Eigenfunctions. Results: Although considerable variability existed within the data, in general, the medial-lateral displacements and vertical displacements of the vocal fold fleshpoints were large compared with anterior-posterior displacements. For both normal and fry-like Phonation, the largest displacements and velocities were concentrated in the upper medial portion. During normal Phonation, the mucosal wave propagated primarily in a vertical direction. Above a certain threshold of subglottal pressure (or stimulation to the recurrent laryngeal nerve), an abrupt transition from chest-like to fry-like Phonation was observed. Conclusions: The study reports unique, quantitative data regarding the medial surface dynamics of an in vivo canine vocal fold during Phonation, capturing both chest-like and fry-like vibration patterns. These data quantify a complex set of dynamics. The mathematical modeling of such complexity is still in its infancy and requires quantitative data of this nature for development, validation, and testing.
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Function of the interarytenoid(IA) muscle in Phonation: in vivo laryngeal model
Yonsei Medical Journal, 1995Co-Authors: Hong Shik Choi, Gerald S. BerkeAbstract:Thyroarytenoid(TA), lateral cricoarytenoid(LCA), and IA muscles are referred to as the adductors of the vocal fold. The TA is known to shorten the vocal folds and to adduct the membranous vocal fold, and the LCA adducts the inter-vocal process region and IA adducts the posterior commissure. Even though IA has an important role for the positioning of the vocal folds during respiration and Phonation together with the action of the posterior cricoarytenoid muscle, little is known about the effect of IA on voice parameters during Phonation. An in vivo canine model was used in five mongrel dogs to examine the role of the IA muscle in controlling Phonation. In two out of five dogs, sound could not be elicited without stimulating the IA branches of the recurrent laryngeal nerves. When the IA was dynamically and statistically stimulated, subglottic pressure, vocal intensity and fundamental frequency were increased. However, open quotient was not changed markedly. These results suggest that the IA affects the voice parameters mainly by controlling subglottic pressure during Phonation.
Jing Kang - One of the best experts on this subject based on the ideXlab platform.
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the therapeutic effects of straw Phonation on vocal fatigue
Laryngoscope, 2020Co-Authors: Jing Kang, Chao Xue, Yi Zhang, Zhewei Lou, Austin Scholp, Jack J JiangAbstract:OBJECTIVES Straw Phonation has been investigated for its vocal warm-up effects on healthy populations and therapeutic effects on voice patients. The purpose of this article was to determine whether it is beneficial for vocal fatigue. STUDY DESIGN Prospective cohort study METHODS: Twenty-five healthy participants were recruited into 1-hour vocal loading tasks followed by 10-minute vocal rest or straw Phonation on 2 different days. Various parameters including Phonation threshold pressure (PTP), mean airflow, closed quotient (CQ), current speaking effort level (EFFT), and laryngeal discomfort (DISC) were acquired at baseline, after vocal load, and after the intervention. RESULTS Increased PTP, EFFT, and DISC were observed after vocal load. Decreased PTP, EFFT, and DISC were then acquired after both vocal rest or straw Phonation. More significant improvements were obtained in straw Phonation when compared with vocal rest. Additionally, significantly increased mean flow and decreased CQ were obtained after straw Phonation when compared to vocal rest. CONCLUSIONS Straw Phonation has the potential to adjust aerodynamics within the vocal tract leading to improved vocal efficiency, optimized vibration mode, and attenuated vocal fatigue. This study provided a promising treatment for vocal fatigue that could have wide clinical relevance to voice users with high voice demands. LEVEL OF EVIDENCE 4 Laryngoscope, 2020.
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lingering effects of straw Phonation exercises on aerodynamic electroglottographic and acoustic parameters
Journal of Voice, 2019Co-Authors: Jing Kang, Chao Xue, David Piotrowski, Ting Gong, Yi Zhang, Jack J JiangAbstract:Summary Objective This study aimed to investigate the duration of straw Phonation effects using aerodynamic, electroglottographic, and acoustic metrics. Methods Twenty-four participants were recruited to perform both a 5-minute and a 10-minute straw Phonation exercise. Upon completion of the exercises, Phonation threshold pressure (PTP), mean airflow, contact quotient, fundamental frequency, jitter, shimmer, and noise-to-harmonics ratio were measured over a 20-minute time frame. Parameters were measured before the intervention (baseline), immediately after the intervention (m0), 5 minutes (m5), 10 minutes (m10), 15 minutes (m15), and 20 minutes (m20) after the intervention. Results PTP significantly decreased immediately after 5 minutes of straw Phonation and returned to initial state within 5 minutes. PTP remained decreased over 5 minutes after 10 minutes of straw Phonation. Mean airflow increased immediately after both 5 minutes and 10 minutes of straw Phonations and remained improved for 20 minutes. No significant changes were obtained for contact quotient and acoustic parameters over the intervention period. Conclusions The results extended our knowledge of proper clinical application of straw Phonation regarding the duration of exercise. This study confirmed that 10 minutes of straw Phonation lead to optimal and relatively continuous effects in PTP and mean airflow. Although straw Phonation did show lingering effects in aerodynamics, repeated practices were recommended to obtain optimum and therapeutic effects.
