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Mucus consistency affects voice physiology and is connected to voice disorders. Nevertheless, the rheological characteristics of human laryngeal mucus from the vocal folds remain unknown. Knowledge about mucus viscoelasticity enables fabrication of artificial mucus with natural properties, more realistic ex-vivo experiments and promotes a better understanding and improved treatment of dysphonia with regard to mucus consistency. We studied human laryngeal mucus samples from the vocal folds with two complementary approaches: 19 samples were successfully applied to particle tracking microrheology (PTM) and five additional samples to oscillatory shear rheology (OSR). Mucus was collected by experienced laryngologists from patients together with demographic data. The analysis of the viscoelasticity revealed diversity among the investigated mucus samples according to their rigidity (absolute G' and G″). Moreover some samples revealed throughout solid-like character (G' > G″), whereas some underwent a change from solid-like to liquid-like (G' < G″). This led to a subdivision into three groups. We assume that the reason for the differences is a variation in the hydration level of the mucus, which affects the mucin concentration and network formation factors of the mucin mesh. The demographic data could not be correlated to the differences, except for the smoking behavior. Mucus of predominant liquid-like character was associated with current smokers.

Pigs have become important animal models in voice research. Several objective parameters exist to characterize the pig voice, but it is not clear which of them are sensitive to the impaired voice quality after laryngeal injury or surgery. In order to conduct meaningful voice research in pigs, it is critical to have standard functional voice outcome measures that can distinguish between normal and impaired voices. For this reason, we investigated 17 acoustic parameters before and early after surgery in three Yucatan mini pigs. Four parameters showed consistent changes between pre- and post-surgery recordings, mostly related to decreased spectral energy in higher frequencies after surgery. We recommend two of these, 50% spectral energy quartile (Q50) and Flux, for objective functional voice assessment of pigs undergoing laryngeal surgery. The long-term goal of this process is to enable quantitative voice outcome tracking of laryngeal surgical interventions in porcine models.

Pigs have become important animal models in voice research. Several objective parameters exist to characterize the pig voice, but it is not clear which of them are sensitive to the impaired voice quality after laryngeal injury or surgery. In order to conduct meaningful voice research in pigs, it is critical to have standard functional voice outcome measures that can distinguish between normal and impaired voices. For this reason, we investigated 17 acoustic parameters before and early after surgery in three Yucatan mini pigs. Four parameters showed consistent changes between pre- and post-surgery recordings, mostly related to decreased spectral energy in higher frequencies after surgery. We recommend two of these, 50% spectral energy quartile (Q50) and Flux, for objective functional voice assessment of pigs undergoing laryngeal surgery. The long-term goal of this process is to enable quantitative voice outcome tracking of laryngeal surgical interventions in porcine models.

Mucus consistency affects voice physiology and is connected to voice disorders. Nevertheless, the rheological characteristics of human laryngeal mucus from the vocal folds remain unknown. Knowledge about mucus viscoelasticity enables fabrication of artificial mucus with natural properties, more realistic ex-vivo experiments and promotes a better understanding and improved treatment of dysphonia with regard to mucus consistency. We studied human laryngeal mucus samples from the vocal folds with two complementary approaches: 19 samples were successfully applied to particle tracking microrheology (PTM) and five additional samples to oscillatory shear rheology (OSR). Mucus was collected by experienced laryngologists from patients together with demographic data. The analysis of the viscoelasticity revealed diversity among the investigated mucus samples according to their rigidity (absolute G' and G″). Moreover some samples revealed throughout solid-like character (G' > G″), whereas some underwent a change from solid-like to liquid-like (G' < G″). This led to a subdivision into three groups. We assume that the reason for the differences is a variation in the hydration level of the mucus, which affects the mucin concentration and network formation factors of the mucin mesh. The demographic data could not be correlated to the differences, except for the smoking behavior. Mucus of predominant liquid-like character was associated with current smokers.

The purpose of the current study was to examine the relationship between the consumption of acidic liquids on the vocal quality of vocally healthy individuals. Acidic foods and liquids are known to be possible causes of common voice disorders because of their putative effect on systemic hydration of the vocal folds impacting their viscoelastic properties and eventually affecting vocal quality, as they are found in over 50% of dysphonic patients (Karkos et al., 2007). This study investigated the effects of acidic foods on vocal quality in comparison to the effects of non-acidic/alkaline beverages in vocally healthy individuals. One hundred participants (50 F and 50 M) were provided with 4 oz of either an acidic or alkaline drink and voice measures were analyzed at baseline, immediately after and 1-hour post consumption. Results demonstrate that acidic beverages negatively impact vocal measures immediately after the consumption of acidic beverages, particularly in females. This research is significant in providing objective information for preventative care and vocal hygiene education.

The movement and control of the vocal folds within the laryngeal cavity enables three crucial physiological functions: 1) allowing respiration by opening, 2) aiding in airway protection by closing, and 3) regulating sound production during phonation. Although treatment options have improved, many of the estimated 7.5 million individuals in the United States who are annually affected by voice-related disorders still face serious challenges related to dysphonia and dysphagia. The need for improved voice-disorder treatments has motivated the work presented in this dissertation which focuses on modeling and manufacturing the vocal folds and aims to answer three main questions: 1) what are the mechanical properties of the vocal folds and how do they change across the full vocal range? 2) how do those properties influence the dynamic behavior of the tissue? and 3) can we manufacture a synthetic vocal fold model that exhibits a desired and controllable dynamic behavior? First, the elastic properties of sixteen porcine vocal folds were evaluated through uniaxial tensile tests on a custom built experimental setup. Stress-strain data was analyzed using an optimization method to yield continuous model parameters which described the linear and nonlinear elastic regions as well as transition points between those regions. Next, the impact of the vocal fold elastic properties on the frequencies of vibration was evaluated through dynamic tests on excised porcine larynges. Sound data was analyzed via a spectrogram and through the use of fast Fourier transforms to study changes in the frequency of vibration while the vocal folds were stretched. Additionally, a mathematical aeroelastic model of phonation was implemented to further evaluate the changing elastic properties on vocal fold dynamics. Next, eight synthetic vocal fold models were created, each with varying mechanical properties and a geometry based on reported anatomical measurements of porcine vocal folds. The synthetic mode

Objectives: To investigate the existing published evidence supporting the role of laryngopharyngeal reflux (LPR) in the development of the select nonfunctional laryngeal diseases of laryngotracheal stenosis, granuloma, leukoplakia, and laryngeal infections Data Sources: PubMed, Cochrane Library, and Scopus. Review Methods: A systematic review was performed by 3 independent investigators for studies providing information about the prevalence and role of LPR in the development of laryngotracheal stenosis, granuloma, leukoplakia, and laryngeal infections. Diagnostic criteria and clinical outcome evaluation of included studies were analyzed with PRISMA criteria. Results: Of the 64 relevant publications, 27 clinical and 4 basic science studies were included. Ten studies used objective reliable examinations for LPR diagnosis (eg, dual- or triple-probe or oropharyngeal pH monitoring, multichannel intraluminal impedance–pH monitoring, or pepsin detection). According to the bias analysis and the results of studies, the association between LPR and laryngotracheal stenosis, leukoplakia, laryngeal papillomatosis, or vocal fold granuloma remains poorly demonstrated. There is a notable heterogeneity among included studies regarding their inclusion criteria, diagnostic methods, and clinical outcome evaluation. Although some experimental findings support the involvement of bile salts and other gastroduodenal proteins active in alkaline pH, no included clinical studies assessed the role of nonacid and mixed reflux through multichannel intraluminal impedance–pH monitoring. Conclusion: The involvement of LPR in the development of leukoplakia, laryngotracheal stenosis, vocal fold granuloma, and laryngeal papillomatosis is currently not demonstrated. The potential relationship between LPR and these select nonfunctional laryngeal diseases must be confirmed through future clinical and experimental studies considering acid, nonacid, and mixed LPR., SCOPUS: re.j, DecretOANoAutActif, info:eu-repo/semantics/published

Agent based models (ABM) were developed to numerically simulate the biological response to surgical vocal fold injury and repair at the physiological level. This study aimed to improve the representation of existing ABM through a combination of empirical and computational experiments. Empirical data of vocal fold cell populations including neutrophils, macrophages and fibroblasts were obtained using flow cytometry up to four weeks following surgical injury. Random Forests were used as a sensitivity analysis method to identify model parameters that were most influential to ABM outputs. Statistical Parameter Optimization Tool for Python was used to calibrate those parameter values to match the ABM-simulation data with the corresponding empirical data from Day 1 to Day 5 following surgery. Model performance was evaluated by verifying if the empirical data fell within the 95% confidence intervals of ABM outputs of cell quantities at Day 7, Week 2 and Week 4. For Day 7, all empirical data were within the ABM output ranges. The trends of ABM-simulated cell populations were also qualitatively comparable to those of the empirical data beyond Day 7. Exact values, however, fell outside of the 95% statistical confidence intervals. Parameters related to fibroblast proliferation were indicative to the ABM-simulation of fibroblast dynamics in final stages of wound healing.

Vocal fold scarring is the fibrotic manifestation of a variety of voice disorders, and is difficult to treat. Tissue engineering therapies provide a potential strategy to regenerate the native tissue microenvironment in order to restore vocal fold functionality. However, major challenges remain in capturing the complexity of the native tissue and sustaining regeneration. We hypothesized that hydrogels with tunable viscoelastic properties that present relevant biological cues to cells might be better suited as therapeutics. Herein, we characterized the response of human vocal fold fibroblasts to four different biomimetic hydrogels: thiolated hyaluronan (HA) crosslinked with poly(ethylene glycol) diacrylate (PEGDA), HA-PEGDA with type I collagen (HA-Col I), HA-PEGDA with type III collagen (HA-Col III) and HA-PEGDA with type I and III collagen (HA-Col I-Col III). Collagen incorporation allowed for interpenetrating fibrils of collagen within the non-fibrillar HA network, which increased the mechanical properties of the hydrogels. The addition of collagen fibrils also reduced hyaluronidase degradation of HA and hydrogel swelling ratio. Fibroblasts encapsulated in the HA-Col gels adopted a spindle shaped fibroblastic morphology by day 7 and exhibited extensive cytoskeletal networks by day 21, suggesting that the incorporation of collagen was essential for cell adhesion and spreading. Cells remained viable and synthesized new DNA throughout 21 days of culture. Gene expression levels significantly differed between the cells encapsulated in the different hydrogels. Relative fold changes in gene expression of MMP1, COL1A1, fibronectin and decorin suggest higher degrees of remodeling in HA-Col I-Col III gels in comparison to HA-Col I or HA-Col III hydrogels, suggesting that the former may better serve as a natural biomimetic hydrogel for tissue engineering applications. STATEMENT OF SIGNIFICANCE: Voice disorders affect about 1/3rd of the US population and significantly reduce

Agent based models (ABM) were developed to numerically simulate the biological response to surgical vocal fold injury and repair at the physiological level. This study aimed to improve the representation of existing ABM through a combination of empirical and computational experiments. Empirical data of vocal fold cell populations including neutrophils, macrophages and fibroblasts were obtained using flow cytometry up to four weeks following surgical injury. Random Forests were used as a sensitivity analysis method to identify model parameters that were most influential to ABM outputs. Statistical Parameter Optimization Tool for Python was used to calibrate those parameter values to match the ABM-simulation data with the corresponding empirical data from Day 1 to Day 5 following surgery. Model performance was evaluated by verifying if the empirical data fell within the 95% confidence intervals of ABM outputs of cell quantities at Day 7, Week 2 and Week 4. For Day 7, all empirical data were within the ABM output ranges. The trends of ABM-simulated cell populations were also qualitatively comparable to those of the empirical data beyond Day 7. Exact values, however, fell outside of the 95% statistical confidence intervals. Parameters related to fibroblast proliferation were indicative to the ABM-simulation of fibroblast dynamics in final stages of wound healing.

Background: Hyaluronan (HA) is a glycosaminoglycan with viscoelastic properties necessary for vocal fold (VF) vibration and voice production. Changes in HAs molecular mass, possibly related to human papilloma virus, could affect formation/persistence of recurrent respiratory papillomatosis (RRP). Aims/Objective: Describing mass and localization of HA and localization of HA receptor CD44 in VF and false vocal folds (FVF) in RRP. Materials and Methods: Biopsies from VF and FVF from 24 RRP patients. Twelve were studied with histo-/immunohistochemistry for HA and CD44 in epithelium, stroma and RRP lesions. Twelve samples were analyzed for HA molecular mass distribution with gas-phase-electrophoretic-molecular-mobility-analyzer (GEMMA). Results: Three of 23 stains (VF and FVF combined) showed faint HA staining in the epithelium; there was more extensive staining in the stroma. CD44 was present throughout all areas in FVF and VF, it did not concur with HA. GEMMA analysis revealed very high mass HA (vHMHA) with more varying amounts in VF. Conclusions/Significance: HA was mainly distributed in the stroma. CD44 not binding to HA might explain the non-inflammatory response described in RRP. Possibly crosslinked vHMHA was seen in VF and FVF, with more variable amounts in VF samples. Counteracting HA crosslinking could become a treatment option in RRP., 背景：透明质酸（HA）是一种糖胺聚糖, 具有声带（VF）振动和发声所必需的粘弹性。HA 分子量的变化可能与人乳头瘤病毒相关, 还可能影响复发性呼吸道乳头状瘤病（RRP）的形成或持续。 目的：描述HA的量和定位, HA受体CD44在VF中的定位和假性声带（FVF）在RRP中的定位。 材料和方法：24名RRP患者的VF和FVF的活组织检查。用组织/免疫组织化学方法研究12个样品的上皮、基质和RRP病变中的HA和CD44。用气-相-电泳 - 分子-迁移率-分析仪（GEMMA）分析另12个样品的HA分子量分布。 结果：23个染色中的3个（VF和FVF组合）在上皮细胞中显示出微弱的HA染色;基质中有更强的染色。 CD44存在于FVF和VF的所有区域, 它与HA不同时存在。 GEMMA分析显示非常高量的HA（vHMHA）, 它在VF中的量多变。 结论/意义：HA主要分布在基质中。 CD44不与HA接合可能解释所描述的RRP中的非炎症反应。在VF和FVF中观察到可能交合的vHMHA, 而在VF样品中具有更多的变量。抗HA交合可能成为RRP的治疗选择。

Background: Hyaluronan (HA) is a glycosaminoglycan with viscoelastic properties necessary for vocal fold (VF) vibration and voice production. Changes in HAs molecular mass, possibly related to human papilloma virus, could affect formation/persistence of recurrent respiratory papillomatosis (RRP). Aims/Objective: Describing mass and localization of HA and localization of HA receptor CD44 in VF and false vocal folds (FVF) in RRP. Materials and Methods: Biopsies from VF and FVF from 24 RRP patients. Twelve were studied with histo-/immunohistochemistry for HA and CD44 in epithelium, stroma and RRP lesions. Twelve samples were analyzed for HA molecular mass distribution with gas-phase-electrophoretic-molecular-mobility-analyzer (GEMMA). Results: Three of 23 stains (VF and FVF combined) showed faint HA staining in the epithelium; there was more extensive staining in the stroma. CD44 was present throughout all areas in FVF and VF, it did not concur with HA. GEMMA analysis revealed very high mass HA (vHMHA) with more varying amounts in VF. Conclusions/Significance: HA was mainly distributed in the stroma. CD44 not binding to HA might explain the non-inflammatory response described in RRP. Possibly crosslinked vHMHA was seen in VF and FVF, with more variable amounts in VF samples. Counteracting HA crosslinking could become a treatment option in RRP., 背景：透明质酸（HA）是一种糖胺聚糖, 具有声带（VF）振动和发声所必需的粘弹性。HA 分子量的变化可能与人乳头瘤病毒相关, 还可能影响复发性呼吸道乳头状瘤病（RRP）的形成或持续。目的：描述HA的量和定位, HA受体CD44在VF中的定位和假性声带（FVF）在RRP中的定位。材料和方法：24名RRP患者的VF和FVF的活组织检查。用组织/免疫组织化学方法研究12个样品的上皮、基质和RRP病变中的HA和CD44。用气-相-电泳 - 分子-迁移率-分析仪（GEMMA）分析另12个样品的HA分子量分布。结果：23个染色中的3个（VF和FVF组合）在上皮细胞中显示出微弱的HA染色;基质中有更强的染色。 CD44存在于FVF和VF的所有区域, 它与HA不同时存在。 GEMMA分析显示非常高量的HA（vHMHA）, 它在VF中的量多变。结论/意义：HA主要分布在基质中。 CD44不与HA接合可能解释所描述的RRP中的非炎症反应。在VF和FVF中观察到可能交合的vHMHA, 而在VF样品中具有更多的变量。抗HA交合可能成为RRP的治疗选择。

Background: Hyaluronan (HA) is a glycosaminoglycan with viscoelastic properties necessary for vocal fold (VF) vibration and voice production. Changes in HAs molecular mass, possibly related to human papilloma virus, could affect formation/persistence of recurrent respiratory papillomatosis (RRP). Aims/Objective: Describing mass and localization of HA and localization of HA receptor CD44 in VF and false vocal folds (FVF) in RRP. Materials and Methods: Biopsies from VF and FVF from 24 RRP patients. Twelve were studied with histo-/immunohistochemistry for HA and CD44 in epithelium, stroma and RRP lesions. Twelve samples were analyzed for HA molecular mass distribution with gas-phase-electrophoretic-molecular-mobility-analyzer (GEMMA). Results: Three of 23 stains (VF and FVF combined) showed faint HA staining in the epithelium; there was more extensive staining in the stroma. CD44 was present throughout all areas in FVF and VF, it did not concur with HA. GEMMA analysis revealed very high mass HA (vHMHA) with more varying amounts in VF. Conclusions/Significance: HA was mainly distributed in the stroma. CD44 not binding to HA might explain the non-inflammatory response described in RRP. Possibly crosslinked vHMHA was seen in VF and FVF, with more variable amounts in VF samples. Counteracting HA crosslinking could become a treatment option in RRP., 背景：透明质酸（HA）是一种糖胺聚糖, 具有声带（VF）振动和发声所必需的粘弹性。HA 分子量的变化可能与人乳头瘤病毒相关, 还可能影响复发性呼吸道乳头状瘤病（RRP）的形成或持续。 目的：描述HA的量和定位, HA受体CD44在VF中的定位和假性声带（FVF）在RRP中的定位。 材料和方法：24名RRP患者的VF和FVF的活组织检查。用组织/免疫组织化学方法研究12个样品的上皮、基质和RRP病变中的HA和CD44。用气-相-电泳 - 分子-迁移率-分析仪（GEMMA）分析另12个样品的HA分子量分布。 结果：23个染色中的3个（VF和FVF组合）在上皮细胞中显示出微弱的HA染色;基质中有更强的染色。 CD44存在于FVF和VF的所有区域, 它与HA不同时存在。 GEMMA分析显示非常高量的HA（vHMHA）, 它在VF中的量多变。 结论/意义：HA主要分布在基质中。 CD44不与HA接合可能解释所描述的RRP中的非炎症反应。在VF和FVF中观察到可能交合的vHMHA, 而在VF样品中具有更多的变量。抗HA交合可能成为RRP的治疗选择。

Background: Hyaluronan (HA) is a glycosaminoglycan with viscoelastic properties necessary for vocal fold (VF) vibration and voice production. Changes in HAs molecular mass, possibly related to human papilloma virus, could affect formation/persistence of recurrent respiratory papillomatosis (RRP). Aims/Objective: Describing mass and localization of HA and localization of HA receptor CD44 in VF and false vocal folds (FVF) in RRP. Materials and Methods: Biopsies from VF and FVF from 24 RRP patients. Twelve were studied with histo-/immunohistochemistry for HA and CD44 in epithelium, stroma and RRP lesions. Twelve samples were analyzed for HA molecular mass distribution with gas-phase-electrophoretic-molecular-mobility-analyzer (GEMMA). Results: Three of 23 stains (VF and FVF combined) showed faint HA staining in the epithelium; there was more extensive staining in the stroma. CD44 was present throughout all areas in FVF and VF, it did not concur with HA. GEMMA analysis revealed very high mass HA (vHMHA) with more varying amounts in VF. Conclusions/Significance: HA was mainly distributed in the stroma. CD44 not binding to HA might explain the non-inflammatory response described in RRP. Possibly crosslinked vHMHA was seen in VF and FVF, with more variable amounts in VF samples. Counteracting HA crosslinking could become a treatment option in RRP., 背景：透明质酸（HA）是一种糖胺聚糖, 具有声带（VF）振动和发声所必需的粘弹性。HA 分子量的变化可能与人乳头瘤病毒相关, 还可能影响复发性呼吸道乳头状瘤病（RRP）的形成或持续。 目的：描述HA的量和定位, HA受体CD44在VF中的定位和假性声带（FVF）在RRP中的定位。 材料和方法：24名RRP患者的VF和FVF的活组织检查。用组织/免疫组织化学方法研究12个样品的上皮、基质和RRP病变中的HA和CD44。用气-相-电泳 - 分子-迁移率-分析仪（GEMMA）分析另12个样品的HA分子量分布。 结果：23个染色中的3个（VF和FVF组合）在上皮细胞中显示出微弱的HA染色;基质中有更强的染色。 CD44存在于FVF和VF的所有区域, 它与HA不同时存在。 GEMMA分析显示非常高量的HA（vHMHA）, 它在VF中的量多变。 结论/意义：HA主要分布在基质中。 CD44不与HA接合可能解释所描述的RRP中的非炎症反应。在VF和FVF中观察到可能交合的vHMHA, 而在VF样品中具有更多的变量。抗HA交合可能成为RRP的治疗选择。

Background: Hyaluronan (HA) is a glycosaminoglycan with viscoelastic properties necessary for vocal fold (VF) vibration and voice production. Changes in HAs molecular mass, possibly related to human papilloma virus, could affect formation/persistence of recurrent respiratory papillomatosis (RRP). Aims/Objective: Describing mass and localization of HA and localization of HA receptor CD44 in VF and false vocal folds (FVF) in RRP. Materials and Methods: Biopsies from VF and FVF from 24 RRP patients. Twelve were studied with histo-/immunohistochemistry for HA and CD44 in epithelium, stroma and RRP lesions. Twelve samples were analyzed for HA molecular mass distribution with gas-phase-electrophoretic-molecular-mobility-analyzer (GEMMA). Results: Three of 23 stains (VF and FVF combined) showed faint HA staining in the epithelium; there was more extensive staining in the stroma. CD44 was present throughout all areas in FVF and VF, it did not concur with HA. GEMMA analysis revealed very high mass HA (vHMHA) with more varying amounts in VF. Conclusions/Significance: HA was mainly distributed in the stroma. CD44 not binding to HA might explain the non-inflammatory response described in RRP. Possibly crosslinked vHMHA was seen in VF and FVF, with more variable amounts in VF samples. Counteracting HA crosslinking could become a treatment option in RRP., 背景：透明质酸（HA）是一种糖胺聚糖, 具有声带（VF）振动和发声所必需的粘弹性。HA 分子量的变化可能与人乳头瘤病毒相关, 还可能影响复发性呼吸道乳头状瘤病（RRP）的形成或持续。 目的：描述HA的量和定位, HA受体CD44在VF中的定位和假性声带（FVF）在RRP中的定位。 材料和方法：24名RRP患者的VF和FVF的活组织检查。用组织/免疫组织化学方法研究12个样品的上皮、基质和RRP病变中的HA和CD44。用气-相-电泳 - 分子-迁移率-分析仪（GEMMA）分析另12个样品的HA分子量分布。 结果：23个染色中的3个（VF和FVF组合）在上皮细胞中显示出微弱的HA染色;基质中有更强的染色。 CD44存在于FVF和VF的所有区域, 它与HA不同时存在。 GEMMA分析显示非常高量的HA（vHMHA）, 它在VF中的量多变。 结论/意义：HA主要分布在基质中。 CD44不与HA接合可能解释所描述的RRP中的非炎症反应。在VF和FVF中观察到可能交合的vHMHA, 而在VF样品中具有更多的变量。抗HA交合可能成为RRP的治疗选择。

Background: Hyaluronan (HA) is a glycosaminoglycan with viscoelastic properties necessary for vocal fold (VF) vibration and voice production. Changes in HAs molecular mass, possibly related to human papilloma virus, could affect formation/persistence of recurrent respiratory papillomatosis (RRP). Aims/Objective: Describing mass and localization of HA and localization of HA receptor CD44 in VF and false vocal folds (FVF) in RRP. Materials and Methods: Biopsies from VF and FVF from 24 RRP patients. Twelve were studied with histo-/immunohistochemistry for HA and CD44 in epithelium, stroma and RRP lesions. Twelve samples were analyzed for HA molecular mass distribution with gas-phase-electrophoretic-molecular-mobility-analyzer (GEMMA). Results: Three of 23 stains (VF and FVF combined) showed faint HA staining in the epithelium; there was more extensive staining in the stroma. CD44 was present throughout all areas in FVF and VF, it did not concur with HA. GEMMA analysis revealed very high mass HA (vHMHA) with more varying amounts in VF. Conclusions/Significance: HA was mainly distributed in the stroma. CD44 not binding to HA might explain the non-inflammatory response described in RRP. Possibly crosslinked vHMHA was seen in VF and FVF, with more variable amounts in VF samples. Counteracting HA crosslinking could become a treatment option in RRP., 背景：透明质酸（HA）是一种糖胺聚糖, 具有声带（VF）振动和发声所必需的粘弹性。HA 分子量的变化可能与人乳头瘤病毒相关, 还可能影响复发性呼吸道乳头状瘤病（RRP）的形成或持续。目的：描述HA的量和定位, HA受体CD44在VF中的定位和假性声带（FVF）在RRP中的定位。材料和方法：24名RRP患者的VF和FVF的活组织检查。用组织/免疫组织化学方法研究12个样品的上皮、基质和RRP病变中的HA和CD44。用气-相-电泳 - 分子-迁移率-分析仪（GEMMA）分析另12个样品的HA分子量分布。结果：23个染色中的3个（VF和FVF组合）在上皮细胞中显示出微弱的HA染色;基质中有更强的染色。 CD44存在于FVF和VF的所有区域, 它与HA不同时存在。 GEMMA分析显示非常高量的HA（vHMHA）, 它在VF中的量多变。结论/意义：HA主要分布在基质中。 CD44不与HA接合可能解释所描述的RRP中的非炎症反应。在VF和FVF中观察到可能交合的vHMHA, 而在VF样品中具有更多的变量。抗HA交合可能成为RRP的治疗选择。

Background: Hyaluronan (HA) is a glycosaminoglycan with viscoelastic properties necessary for vocal fold (VF) vibration and voice production. Changes in HAs molecular mass, possibly related to human papilloma virus, could affect formation/persistence of recurrent respiratory papillomatosis (RRP). Aims/Objective: Describing mass and localization of HA and localization of HA receptor CD44 in VF and false vocal folds (FVF) in RRP. Materials and Methods: Biopsies from VF and FVF from 24 RRP patients. Twelve were studied with histo-/immunohistochemistry for HA and CD44 in epithelium, stroma and RRP lesions. Twelve samples were analyzed for HA molecular mass distribution with gas-phase-electrophoretic-molecular-mobility-analyzer (GEMMA). Results: Three of 23 stains (VF and FVF combined) showed faint HA staining in the epithelium; there was more extensive staining in the stroma. CD44 was present throughout all areas in FVF and VF, it did not concur with HA. GEMMA analysis revealed very high mass HA (vHMHA) with more varying amounts in VF. Conclusions/Significance: HA was mainly distributed in the stroma. CD44 not binding to HA might explain the non-inflammatory response described in RRP. Possibly crosslinked vHMHA was seen in VF and FVF, with more variable amounts in VF samples. Counteracting HA crosslinking could become a treatment option in RRP., 背景：透明质酸（HA）是一种糖胺聚糖, 具有声带（VF）振动和发声所必需的粘弹性。HA 分子量的变化可能与人乳头瘤病毒相关, 还可能影响复发性呼吸道乳头状瘤病（RRP）的形成或持续。目的：描述HA的量和定位, HA受体CD44在VF中的定位和假性声带（FVF）在RRP中的定位。材料和方法：24名RRP患者的VF和FVF的活组织检查。用组织/免疫组织化学方法研究12个样品的上皮、基质和RRP病变中的HA和CD44。用气-相-电泳 - 分子-迁移率-分析仪（GEMMA）分析另12个样品的HA分子量分布。结果：23个染色中的3个（VF和FVF组合）在上皮细胞中显示出微弱的HA染色;基质中有更强的染色。 CD44存在于FVF和VF的所有区域, 它与HA不同时存在。 GEMMA分析显示非常高量的HA（vHMHA）, 它在VF中的量多变。结论/意义：HA主要分布在基质中。 CD44不与HA接合可能解释所描述的RRP中的非炎症反应。在VF和FVF中观察到可能交合的vHMHA, 而在VF样品中具有更多的变量。抗HA交合可能成为RRP的治疗选择。

Humans have been interested in bowel sounds and wondered about their origins for millennia. To better understand the phenomenon, a mathematical model of bowel sound generation was developed based on a spring-mass-damping system. This is similar to vocal folds models for speech. The bowel sound model has four parameters that link to bowel activities: the individual wave component, pressure index, component quantity, and component interval time. All types of bowel sound documented previously can be modelled by combining different values for these parameters. Further, a 2500 ms bowel sound incorporating all the common types was simulated to present the model's accuracy.

Introduction: Exercise-induced laryngeal obstruction (EILO) is a condition associated with stridor, wheezing and dyspnea during exercise. The condition is commonly divided into two subtypes, glottic and supraglottic, depending on the level of the obstruction in the larynx. The obstruction may also occur in a combined form. At Uppsala University Hospital there are a few different treatment options for EILO but they are most commonly referred to speech and language pathology treatment (SLP-treatment). Objectives: The purpose of this study was to examine (1) the perceived effect of SLP-treatment on individuals with EILO and (2) to examine whether a difference in the perceived effect was due to type of EILO. A third aim (3) was to examine the presence of voice symptoms in this group. Study designs:This study investigated separate objectives and reported results from both a retrospective cross-sectional study and a cross-sectional study. Methods:51 participants with EILO were referred to SLP-treatment between year 2007 and 2017. 37 of the participants completed a survey on the perceived effect of SLP-treatment. All participants answered a questionnaire about voice symptoms, Screen6. Results: A majority, 54% of the 37 participants who had undergone SLP-treatment, reported being helped by the treatment. In total, 51 participants diagnosed with EILO answered the survey, generating a response rate of 52%. The result showed that 31 % of the participants reported voice problems. Voice problems were defined as having two or more voice symptoms weekly or daily on Screen6. Conclusions:(1) In this study a majority of the participants reported SLP-treatment as helpful. (2) No significant difference between the perceived effect of the intervention and type of EILO existed. (3) 31% of the participants had a voice problem according to Screen6. This number is higher, than in the general population and in other risk groups and may indicate a greater risk of voice disorders

Introduction: Exercise-induced laryngeal obstruction (EILO) is a condition associated with stridor, wheezing and dyspnea during exercise. The condition is commonly divided into two subtypes, glottic and supraglottic, depending on the level of the obstruction in the larynx. The obstruction may also occur in a combined form. At Uppsala University Hospital there are a few different treatment options for EILO but they are most commonly referred to speech and language pathology treatment (SLP-treatment). Objectives: The purpose of this study was to examine (1) the perceived effect of SLP-treatment on individuals with EILO and (2) to examine whether a difference in the perceived effect was due to type of EILO. A third aim (3) was to examine the presence of voice symptoms in this group. Study designs:This study investigated separate objectives and reported results from both a retrospective cross-sectional study and a cross-sectional study. Methods:51 participants with EILO were referred to SLP-treatment between year 2007 and 2017. 37 of the participants completed a survey on the perceived effect of SLP-treatment. All participants answered a questionnaire about voice symptoms, Screen6. Results: A majority, 54% of the 37 participants who had undergone SLP-treatment, reported being helped by the treatment. In total, 51 participants diagnosed with EILO answered the survey, generating a response rate of 52%. The result showed that 31 % of the participants reported voice problems. Voice problems were defined as having two or more voice symptoms weekly or daily on Screen6. Conclusions:(1) In this study a majority of the participants reported SLP-treatment as helpful. (2) No significant difference between the perceived effect of the intervention and type of EILO existed. (3) 31% of the participants had a voice problem according to Screen6. This number is higher, than in the general population and in other risk groups and may indicate a greater risk of voice disorders

Humans have been interested in bowel sounds and wondered about their origins for millennia. To better understand the phenomenon, a mathematical model of bowel sound generation was developed based on a spring-mass-damping system. This is similar to vocal folds models for speech. The bowel sound model has four parameters that link to bowel activities: the individual wave component, pressure index, component quantity, and component interval time. All types of bowel sound documented previously can be modelled by combining different values for these parameters. Further, a 2500 ms bowel sound incorporating all the common types was simulated to present the model's accuracy.

The so-called Laryngeal Adductor Reflex (LAR) protects the respiratory tract from particle intrusion by quickly approximating the vocal folds to close the free glottal space. An impaired LAR may be associated with an increased risk of aspiration and other adverse conditions. To evaluate the integrity of the LAR, we recently developed an endoscopic prototype for LAR triggering by shooting accelerated droplets onto a predefined laryngeal target region. We now modified the existing droplet-dispensing system to adapt the fluid system pressure as well as the valve opening time to user-chosen values autonomously. This has been accomplished using a microcontroller board connected to a pressure sensor and a mechatronic syringe pump. For performance validation, we designed a measurement setup capable of tracking the droplet along a vertical trajectory. In addition to the experimental setup, the influence of parameters such as system pressure and valve opening time on the micro-droplet formation is presented. Further development will enable the physician to adjust the droplet momentum by setting a single input value on the microcontroller-based setup, thus further increasing usability of the diagnostic device.

OBJECTIVES/HYPOTHESIS: To study the hyaluronan occurrence in human vocal folds, with special regards to gender and smoking and to discuss the implications of findings. STUDY DESIGN: This is a descriptive/morphologic study. METHODS: Sixteen cadaveric vocal folds from eight individuals between 58 and 90 years old (six women and two men) were removed and studied morphologically. Three of the individuals had been cigarette smokers. A direct method for hyaluronan histochemistry using a hyaluronan-binding protein probe (HABP) was used to visualize the polysaccharide. Five examiners performed an analysis of the intensities of hyaluronan staining, independently. RESULTS: We observed intense hyaluronan staining of the vocal folds of which those from women stained considerably stronger than those from men. Stratified squamous epithelium stained for hyaluronan in all sections, whereas respiratory epithelium only stained weakly or not at all. The highest accumulation of hyaluronan occurred subepithelially in the lamina propria, corresponding to Reinke's space. It was observed that vocal folds from smokers were more intensively stained than those from nonsmokers. CONCLUSIONS: Hyaluronan is found in all layers of the human vocal fold. Contradictory to earlier studies, hyaluronan was visualized in squamous epithelium, where it may function as an impact protector. The occurrence of hyaluronan in smokers may have implications in the development of vocal fold inflammation and tumor initiation as hyaluronan is an important molecule in these processes.

Analysis of voice pathologies may require vocal fold models that include relevant features such as vocal fold asymmetric collision. The present study numerically addresses the problem of frictionless asymmetric collision in a self-sustained three-dimensional continuum model of the vocal folds. Theoretical background and numerical analysis of the finite-element position-based contact model are presented, along with validation. A novel contact detection mechanism capable to detect collision in asymmetric oscillations is developed. The effect of inexact contact constraint enforcement on vocal fold dynamics is examined by different variational methods for inequality constrained minimization problems, namely the Lagrange multiplier method and the penalty method. In contrast to the penalty solution, which is related to classical spring-like contact forces, numerical examples show that the parameter-independent Lagrange multiplier solution is more robust and accurate in the estimation of dynamical and mechanical features at vocal fold contact. Furthermore, special attention is paid to the temporal integration schemes in relation to the contact problem, the results suggesting an advantage of highly diffusive schemes. Finally, vocal fold contact enforcement is shown to affect asymmetric oscillations. The present model may be adapted to existing vocal fold models, which may contribute to a better understanding of the effect of the non-linear contact phenomenon on phonation.

Compressible large eddy simulation is employed to numerically investigate the laryngeal flow. Symmetric static models of the human larynx with a divergent glottis are considered, with the presence of false vocal folds (FVFs). The compressible study agrees well with that of the incompressible study. Due to the high enough Reynolds number, the flow is unsteady and develops asymmetric states downstream of the glottis. The glottal jet curvature decreases with the presence of FVFs or the ventricular folds. The gap between the FVFs stretches the flow structure and reduces the jet curvature. The presence of FVFs has a significant effect on the laryngeal flow resistance. The intra-glottal vortex structures are formed on the divergent wall of the glottis, immediately downstream of the separation point. The vortices are then convected downstream and characterized by a significant negative static pressure. The FVFs are a main factor in the generation of stronger vortices, and thus on the closure of the TVFs. The direct link between the FVFs geometry and the motion of the TVFs, and by extension to the voice production, is of interest for medical applications as well as future research works. The presence of the FVFs also changes the dominant frequencies in the velocity and pressure spectra., QC 20150612

The human voice organ fits in a small space having a characteristic length of ~cm. Large amounts of complex physical phenomena combine in it so as to produce sounds. Despite of the reduced dimensions of the voice organ, however, a complete numerical simulation of its physics is still out of reach, even when using massively parallel supercomputers. This has led researchers to split the problem of voice generation into parts, independently focusing for instance, on simulating the self-oscillation of the vocal folds to generate the glottal pulse, the propagation of acoustic waves in moving vocal tracts to produce diphthongs, or the diffraction of the glottal jet pressure by the teeth, which results in fricative sounds. In this workshop, a review will be given of the type of equations and difficulties encountered when trying to solve these type of phenomena and show that, under some assumptions, the first unified simulations coupling the mechanics, aerodynamics and acoustics of the vocal folds and vocal tract, may not be as far as one might think. A workflow from 3D biomechanical models, to the generation of vocal fold self-oscillations, flow and acoustic waves to the radiated sound may be feasible in the short term., QC 20210920

[Objectives/Hypothesis]Reactive oxygen species (ROS) are associated with aging. Astaxanthin (AST) is a strong antioxidant and has been reported to prevent various ROS-induced diseases. In the current study, we investigated the effect of AST on age-associated histological and mRNA changes of vocal folds. [Study Design]Prospective animal experiment with control. [Methods]Six-month-old Sprague-Dawley rats were fed on a normal powder diet with 0.01% (w/w) AST (aged AST-treated group) or without AST (aged sham-treated group). After 12 months of feeding, the larynges were harvested for histology, immunohistochemical detection of 4-hydroxy-2-nonenal (4-HNE), and quantitative real-time polymerase chain reaction for basic fibroblast growth factor (bFGF) and hepatocyte growth factor (HGF). Thirteen-week-old rats were used as a young control group (young group). [Results]The expression of 4-HNE, an oxidative stress marker, significantly increased in the two aged groups compared with the young group. Histological examination showed that the deposition of hyaluronic acid in the lamina propria (LP) was significantly reduced in the aged sham-treated group compared with the young group, but no significant difference was observed between the aged AST-treated group and the young group. There were no significant differences in the mRNA expression of bFGF and HGF between the aged AST-treated group and the young group, although the expression of these genes was significantly reduced in the aged sham-treated group as compared with the young group. [Conclusions]These results suggest that AST has the potential to attenuate age-associated changes of vocal folds.

Objectives/hypothesisOne potential treatment for vocal fold injury or neoplasia is to replace the entire vocal fold with a tissue-engineered scaffold. This scaffold should ideally have similar mechanical properties and extracellular matrix composition as the native vocal fold. As one approach toward this goal, we decellularized human vocal folds and characterized their mechanical properties and extracellular matrix microstructure.Study designBasic science investigation.MethodsHuman vocal folds were dissected from the laryngeal framework and treated with sodium dodecyl sulfate (SDS) to remove all cells. Mechanical properties were measured by indentation before and after SDS treatment. The extracellular matrix components of collagen, laminin, elastin, and hyaluronic acid were also characterized before and after decellularization using histology and immunofluorescence.ResultsAfter 4 days of SDS treatment, we obtained a scaffold that retained the original geometry of the vocal fold but was devoid of cells. The elastic modulus of the vocal folds did not change significantly before and after decellularization. Upon qualitative inspection, the decellularized vocal folds retained the original collagen, elastin, and laminin content and orientation but lost the original hyaluronic acid.ConclusionsVocal folds can be decellularized using SDS without adversely affecting its mechanical stiffness and fibrous extracellular matrix. This preliminary study demonstrates the potential of a decellularized scaffold to serve as a tissue-engineered construct for vocal fold replacement.

The purpose of the study is to examine in what way singing teachers from different genres relate to categorization of the female singing voice. Information has been collected through interviews with six singing teachers, active at different levels. The method applied is qualitative interview inspection. The results show that the six singing teachers have different views of voice categorization of their students. Three out of six consider voice categorization important while the rest do not consider this being relevant to the learning situation. The categorization procedures used by the singing teachers varies between the informants. The teachers state that they combine knowledge acquired from their own education in combination with personal skills derived from practical teaching experience. Thereby they claim to have found a method for voice categorization suitable for their individual pedagogical aims., Syftet med studien är att undersöka hur sångpedagoger i olika genrer förhåller sig till röstkategorisering av den kvinnliga sångrösten. Data har insamlats genom intervjuer med sex sångpedagoger verksamma på olika nivåer, från kulturskola till musikhögskola. Metoden som tillämpats är kvalitativ intervjuundersökning. Resultatet visar att de sex pedagogerna har olika syn på röstkategorisering. Tre av sex anser det vara viktigt medan de övriga inte anser att det är något sångpedagogen bör ta upp med sina elever. Tillvägagångssätten på vilka sångpedagogerna hävdar att de kategoriserar röster skiljer sig åt. De säger sig kombinera kunskap de förvärvat under sin utbildning med praktiskt kunnande härlett ur personlig lärarerfarenhet, och har därigenom funnit ett tillvägagångssätt för röstkategorisering som passar deras pedagogiska syften.

Objectives/hypothesisOne potential treatment for vocal fold injury or neoplasia is to replace the entire vocal fold with a tissue-engineered scaffold. This scaffold should ideally have similar mechanical properties and extracellular matrix composition as the native vocal fold. As one approach toward this goal, we decellularized human vocal folds and characterized their mechanical properties and extracellular matrix microstructure.Study designBasic science investigation.MethodsHuman vocal folds were dissected from the laryngeal framework and treated with sodium dodecyl sulfate (SDS) to remove all cells. Mechanical properties were measured by indentation before and after SDS treatment. The extracellular matrix components of collagen, laminin, elastin, and hyaluronic acid were also characterized before and after decellularization using histology and immunofluorescence.ResultsAfter 4 days of SDS treatment, we obtained a scaffold that retained the original geometry of the vocal fold but was devoid of cells. The elastic modulus of the vocal folds did not change significantly before and after decellularization. Upon qualitative inspection, the decellularized vocal folds retained the original collagen, elastin, and laminin content and orientation but lost the original hyaluronic acid.ConclusionsVocal folds can be decellularized using SDS without adversely affecting its mechanical stiffness and fibrous extracellular matrix. This preliminary study demonstrates the potential of a decellularized scaffold to serve as a tissue-engineered construct for vocal fold replacement.

The purpose of the study is to examine in what way singing teachers from different genres relate to categorization of the female singing voice. Information has been collected through interviews with six singing teachers, active at different levels. The method applied is qualitative interview inspection. The results show that the six singing teachers have different views of voice categorization of their students. Three out of six consider voice categorization important while the rest do not consider this being relevant to the learning situation. The categorization procedures used by the singing teachers varies between the informants. The teachers state that they combine knowledge acquired from their own education in combination with personal skills derived from practical teaching experience. Thereby they claim to have found a method for voice categorization suitable for their individual pedagogical aims., Syftet med studien är att undersöka hur sångpedagoger i olika genrer förhåller sig till röstkategorisering av den kvinnliga sångrösten. Data har insamlats genom intervjuer med sex sångpedagoger verksamma på olika nivåer, från kulturskola till musikhögskola. Metoden som tillämpats är kvalitativ intervjuundersökning. Resultatet visar att de sex pedagogerna har olika syn på röstkategorisering. Tre av sex anser det vara viktigt medan de övriga inte anser att det är något sångpedagogen bör ta upp med sina elever. Tillvägagångssätten på vilka sångpedagogerna hävdar att de kategoriserar röster skiljer sig åt. De säger sig kombinera kunskap de förvärvat under sin utbildning med praktiskt kunnande härlett ur personlig lärarerfarenhet, och har därigenom funnit ett tillvägagångssätt för röstkategorisering som passar deras pedagogiska syften.

The purpose of the study is to examine in what way singing teachers from different genres relate to categorization of the female singing voice. Information has been collected through interviews with six singing teachers, active at different levels. The method applied is qualitative interview inspection. The results show that the six singing teachers have different views of voice categorization of their students. Three out of six consider voice categorization important while the rest do not consider this being relevant to the learning situation. The categorization procedures used by the singing teachers varies between the informants. The teachers state that they combine knowledge acquired from their own education in combination with personal skills derived from practical teaching experience. Thereby they claim to have found a method for voice categorization suitable for their individual pedagogical aims., Syftet med studien är att undersöka hur sångpedagoger i olika genrer förhåller sig till röstkategorisering av den kvinnliga sångrösten. Data har insamlats genom intervjuer med sex sångpedagoger verksamma på olika nivåer, från kulturskola till musikhögskola. Metoden som tillämpats är kvalitativ intervjuundersökning. Resultatet visar att de sex pedagogerna har olika syn på röstkategorisering. Tre av sex anser det vara viktigt medan de övriga inte anser att det är något sångpedagogen bör ta upp med sina elever. Tillvägagångssätten på vilka sångpedagogerna hävdar att de kategoriserar röster skiljer sig åt. De säger sig kombinera kunskap de förvärvat under sin utbildning med praktiskt kunnande härlett ur personlig lärarerfarenhet, och har därigenom funnit ett tillvägagångssätt för röstkategorisering som passar deras pedagogiska syften.

ObjectivesTo present our experience using the first commercially available optical coherence tomography (OCT) device for use in the head, neck, and upper aerodigestive tract and to determine the feasibility and efficacy of this system in comparison with our previous experience using other research OCT systems.MethodsUsing the Niris OCT imaging system (Imalux, Cleveland, OH), we obtained OCT images of benign and premalignant laryngeal disease in 33 patients undergoing surgical head and neck endoscopy. This imaging system has a spatial depth resolution of 10 to 20 mum and a depth scanning range of 2.2 mm, obtaining images of 200 x 200 pixels at a maximum frame rate of 0.7 Hz. The scanning mechanism of the device is located at the distal end of a flexible probe that is placed in contact or near-contact with the area of interest. The tip of the probe was inserted through a rigid laryngoscope, and still images were obtained.ResultsOCT images of arytenoids, aryepiglottic folds, piriform sinus, epiglottis, and true and false vocal cords were obtained. In patients whose OCT images were taken from normal tissue, the normal microstructures were clearly identified, as well as disruption of the latter in malignant pathologies.ConclusionsThe device can easily be incorporated into the operating room and requires minimal set-up and staff to operate. OCT imaging with this device potentially offers an efficient, quick, and reliable imaging modality in guiding surgical biopsies, intraoperative decision making, and therapeutic options of various laryngeal pathologies and premalignant disease.

ObjectivesTo present our experience using the first commercially available optical coherence tomography (OCT) device for use in the head, neck, and upper aerodigestive tract and to determine the feasibility and efficacy of this system in comparison with our previous experience using other research OCT systems.MethodsUsing the Niris OCT imaging system (Imalux, Cleveland, OH), we obtained OCT images of benign and premalignant laryngeal disease in 33 patients undergoing surgical head and neck endoscopy. This imaging system has a spatial depth resolution of 10 to 20 mum and a depth scanning range of 2.2 mm, obtaining images of 200 x 200 pixels at a maximum frame rate of 0.7 Hz. The scanning mechanism of the device is located at the distal end of a flexible probe that is placed in contact or near-contact with the area of interest. The tip of the probe was inserted through a rigid laryngoscope, and still images were obtained.ResultsOCT images of arytenoids, aryepiglottic folds, piriform sinus, epiglottis, and true and false vocal cords were obtained. In patients whose OCT images were taken from normal tissue, the normal microstructures were clearly identified, as well as disruption of the latter in malignant pathologies.ConclusionsThe device can easily be incorporated into the operating room and requires minimal set-up and staff to operate. OCT imaging with this device potentially offers an efficient, quick, and reliable imaging modality in guiding surgical biopsies, intraoperative decision making, and therapeutic options of various laryngeal pathologies and premalignant disease.

The investigation of vocal folds viscoelastic properties in an animal model (rabbit) after injection of various augmentation substances, 6 months after injection, is reported. The injected materials were: hyaluronan-based materials (Hylan B gel and Deflux(R)), cross-linked collagen (Zyplast(R)) and polytetrafluoroethylene (Teflon(R)). Rheological properties of the augmentation substances were also evaluated. The results from these animal experiments indicate that the viscoelastic properties of the vocal folds injected with Deflux(R), Zyplast(R) and Hylan B gel are similar to the healthy vocal folds (non-injected samples) used as control, thus demonstrating that these materials are good candidates for further studies aimed at restoring/preserving the vibratory capacity of the vocal folds with injection treatment in glottal insufficiency.

This study examined the minimum range of variability in vocal fold vibration during syllables as measured from glottal airflow. Repeated samples were taken from adults with healthy vocal folds four times within two weeks and four consecutive trials within one day. Sources of extraneous variability were minimized by (a) controlling subglottal pressure, (b) age-matching subjects, (c) controlling time of sampling, (d) taking menstrual cycle into account, and (e) low-pass filtering rather than inverse filtering oral airflow. Eleven females and 11 age-matched males received medical exams to assess laryngeal health and vocal fold vibratory pattern. To elicit 3 different modes of vibration, subjects produced "bap" syllable strings at 5, 8, and 12 cm H 2 O subglottal pressure (P S ). FM tape recordings were made of oral airflow (collected with Rothenberg mask), subglottal pressure and electroglottograph signals. Data were digitized and low-pass filters extracted glottal airflow. Indices of variability were Coefficient of Variation (CV in %) and Median Absolute Deviation (MAD). Dependent measures were Fundamental Frequency (F 0 ), Amplitude Flow (A), Minimum Flow (L), Mean Flow (M), Open Quotient (Q O ), and Spectral Balance Ratio (SBR: ratio of the sum of harmonics above F 0 to that at F 0 ). Ranked CV data across subjects and measures indicated that F0 had the smallest range of variability (0.6%), and L the largest (101%). F 0 most often had a small range of variability, while L most often had a large range. Females had larger MAD values than males for F 0 , Q O and SBR; males for A, L and M. Nonparametric statistical analyses revealed that magnitude of variability for L was not affected by sex of subject, subglottal pressure level, or time frame of testing, while the magnitude of variability for A was affected by sex, P S level, and time frame. Conclusions include: (a) selected measures of glottal airflow do not vary in the same manner by sex, P S level, or time frame; (b

Bakalářská práce náleží do oblasti bioakustiky a biomechaniky hlasu. Zabývá se modelováním jednoduchých analytických modelů hlasivek, konkrétně jejich vynuceným kmitáním pomocí budicích sil s harmonickým průběhem. Součástí práce je i anatomie dýchacího a hlasového ústrojí a popis základních teorií tvorby hlasu, na kterou navazuje přehled hmotových výpočtových modelů hlasivek., This bachelor’s thesis belongs to the branch of bioacoustics and biomechanics. It deals with the modelling of simple analytic models of vocal folds, specifically with their forced oscillation caused by a harmonic excitation force. The thesis also includes an anatomy of the respiratory tract and the vocal system, a description of the principal theories of voice production, and an overview of the vocal folds’ mass models.

Následující diplomová práce se zabývá vytvořením výpočtového modelu pro šíření akustických vln lidským vokálním traktem a následně prostorem okolo hlavy člověka. Detailní zmapování akustického pole okolo hlavy člověka je důležité pro zpřesnění měření lidského hlasu. Součástí práce je tvorba trojrozměrného konečně-prvkového modelu lidské hlavy a vokálního traktu při fonaci samohlásky /:a/ na základě dat z výpočtové tomografie, dále rešeršní studie funkce vokálního traktu, biomechanika tvorby lidského hlasu, přehled doposud v literatuře publikovaných výpočtových modelů a v literatuře uváděných měření šíření hlasu lidským vokálním traktem a v prostoru okolo hlavy. Následuje samotné výpočtové řešení šíření akustických vln od hlasivek skrz vokální trakt a prostorem okolo hlavy člověka při uvažování akustické absorpce na stěnách vokálního traktu a na pokožce hlavy pro různé typy buzení. Výsledky jsou porovnány s doposud publikovanými měřeními šíření lidského hlasu a analyzují se hlavně zkreslení frekvenčních spekter v jednotlivých bodech v prostoru okolo hlavy a v její blízkosti kam se obvykle umisťují snímací mikrofony. Výsledků výpočtového modelování bude možné eventuálně využít pro frekvenční korekce pro různé polohy mikrofonů snímající šíření hlasu při jeho diagnostice, řeči nebo zpěvu., The following master thesis deals with creating a computational model for acoustic wave distribution by the human vocal tract and then the space around a human head. Detailed mapping of the sound field around the human head is important for more accurate measurement of the human voice. Part of this work is the creation of three-dimensional finite element model of the human head and the vocal tract during phonation of the vowel /:a/ based on the data from the computational tomography. Further the literature search of the function of the vocal tract, biomechanics of the making of the human voice, an overview of the computational models so far published in the literature and in literature reported measurements of the distribution of the human voice by the vocal tract and then in the space around the head . The following is the actual numerical solution of the acoustic waves distribution from the vocal cords through the vocal tract and then the space around the human head when thinking of acoustic absorption on the walls of the vocal tract and on the skin of the head for different types of waking of the model. The results are compared with previously published measurements of the distribution of the human voice and mainly the distortion of the frequency spectra at each specific node in the space around the head and in its vicinity of where the sensor microphones are typically placed are analyzed. Results of the computational modeling will eventually be used for frequency correction for various positions of the microphones scanning the voice distribution in its diagnosis, speech or singing.

Tato práce je zaměřena na průzkum existujících modelů geometrie a modelů materiálových vlastností lidských hlasivek. Její snahou je shromáždit a utřídit informace tak, aby vznikl přehled používaných geometrií a vlastností materiálu. Dále je pak pomocí modální analýzy zkoumán vliv modulu pružnosti v tahu jednotlivých vrstev hlasivek na vlastní frekvence. Tato analýza je provedena pro jeden prostorový (3D) a dva rovinné (2D) modely geometrie., This theses focuses on a research of existing material and geometry models. Its effort is to gather and organize gathered information thus so that overview of geometries and material models was created. Furthermore an influence of Young’s modulus in tension of particular vocal fold layers was investigated using modal analysis. This was made for one three-dimensional (3D) and two two-dimensional (2D) geometry models.

Následující diplomová práce se zabývá vytvořením výpočtového modelu pro šíření akustických vln lidským vokálním traktem a následně prostorem okolo hlavy člověka. Detailní zmapování akustického pole okolo hlavy člověka je důležité pro zpřesnění měření lidského hlasu. Součástí práce je tvorba trojrozměrného konečně-prvkového modelu lidské hlavy a vokálního traktu při fonaci samohlásky /:a/ na základě dat z výpočtové tomografie, dále rešeršní studie funkce vokálního traktu, biomechanika tvorby lidského hlasu, přehled doposud v literatuře publikovaných výpočtových modelů a v literatuře uváděných měření šíření hlasu lidským vokálním traktem a v prostoru okolo hlavy. Následuje samotné výpočtové řešení šíření akustických vln od hlasivek skrz vokální trakt a prostorem okolo hlavy člověka při uvažování akustické absorpce na stěnách vokálního traktu a na pokožce hlavy pro různé typy buzení. Výsledky jsou porovnány s doposud publikovanými měřeními šíření lidského hlasu a analyzují se hlavně zkreslení frekvenčních spekter v jednotlivých bodech v prostoru okolo hlavy a v její blízkosti kam se obvykle umisťují snímací mikrofony. Výsledků výpočtového modelování bude možné eventuálně využít pro frekvenční korekce pro různé polohy mikrofonů snímající šíření hlasu při jeho diagnostice, řeči nebo zpěvu., The following master thesis deals with creating a computational model for acoustic wave distribution by the human vocal tract and then the space around a human head. Detailed mapping of the sound field around the human head is important for more accurate measurement of the human voice. Part of this work is the creation of three-dimensional finite element model of the human head and the vocal tract during phonation of the vowel /:a/ based on the data from the computational tomography. Further the literature search of the function of the vocal tract, biomechanics of the making of the human voice, an overview of the computational models so far published in the literature and in literature reported measurements of the distribution of the human voice by the vocal tract and then in the space around the head . The following is the actual numerical solution of the acoustic waves distribution from the vocal cords through the vocal tract and then the space around the human head when thinking of acoustic absorption on the walls of the vocal tract and on the skin of the head for different types of waking of the model. The results are compared with previously published measurements of the distribution of the human voice and mainly the distortion of the frequency spectra at each specific node in the space around the head and in its vicinity of where the sensor microphones are typically placed are analyzed. Results of the computational modeling will eventually be used for frequency correction for various positions of the microphones scanning the voice distribution in its diagnosis, speech or singing.

Práce se zabývá vytvořením rovinného výpočtového modelu lidských hlasivek, zahrnující interakci struktury a proudícího vzduchu. Na tomto modelu je zkoumán vliv změn vrstev tkání hlasivek (tuhost, tloušťka) a jejich projevy na snímku videokymogramu. Analýza výsledků se zabývá také vyhodnocením tlaků ve vybraných bodech pod, mezi a nad hlasivkami. Výsledky naznačují možnou podobnost s chováním lidských hlasivek s patologiemi. Součástí práce je i rešerše funkce hlasivek, přehled patologií a užívaných výpočtových modelů hlasivek., Master´s thesis deals with creating planar computational model of human folds, involving fluid-structure interaction. With this model, the influence of changes in vocal folds tissue layers (stiffness, thickness) and their effects on the videokymograph image are studied. Analysis of the results also deals with the evaluation of pressure at selected points below, between and above the vocal folds. The results indicate a possible similarity with the behavior of human vocal folds with pathology. Background research of vocal folds function, an overview of vocal folds pathology and summary of computational models are included.

Cílem práce je na modelu hlasivky provést analýzu vlivu materiálových parametrů jednotlivých vrstev tkáně hlasivek na šíření slizniční vlny. Nejdříve je na základě literatury uveden stručný přehled současných přístupů při experimentálním a výpočtovém modelování šíření slizniční vlny. Dále je pak pomocí modální analýzy zkoumán vliv modulu pružnosti v tahu epitelu a povrchové laminy proprii na vlastní frekvence a tvary kmitů. Šíření slizniční vlny bylo následně analyzováno pomocí přechodové analýzy jako odezva hlasivky na rázové buzení silou na spodní část hlasivky. Byl vyhodnocován vliv materiálových parametrů na amplitudu a rychlost šíření slizniční vlny po povrchu hlasivky. V závěru práce je uvedeno doporučení, dle zaznamenaných výsledků, použít nižší moduly pružnosti v tahu povrchové laminy proprii v modelech s interakcí s proudem vzduchu, protože je zde mnohem výraznější šíření slizniční vlny odpovídající chování skutečných lidských hlasivek., The aim of this thesis is to analyze the influence of material parameters of individual layers of vocal cord tissue on the propagation of mucosal waves on the vocal cord model. First, a brief overview of current approaches in experimental and computational modeling of mucosal wave propagation is given on the basis of the literature. Furthermore, the influence of the modulus of elasticity in the tensile epithelium and the surface lamina of propria on the natural frequencies and shapes of oscillations is investigated by means of modal analysis. Mucosal wave propagation was then analyzed using transient analysis in response to the vocal cords to shock excitation by force on the lower part of the vocal cords. The influence of material parameters on the amplitude and speed of mucosal wave propagation over the vocal cord surface was evaluated. In the end of this thesis, the recommendation is given, according to the recorded results, to use lower modulus of elasticity in tension of the surface lamina propria in models with interaction with air flow, because there is much more pronounced mucosal wave propagation corresponding to the behavior of real human vocal cords.

Bakalářská práce náleží do oblasti bioakustiky a biomechaniky hlasu. Zabývá se modelováním jednoduchých analytických modelů hlasivek, konkrétně jejich vynuceným kmitáním pomocí budicích sil s harmonickým průběhem. Součástí práce je i anatomie dýchacího a hlasového ústrojí a popis základních teorií tvorby hlasu, na kterou navazuje přehled hmotových výpočtových modelů hlasivek., This bachelor’s thesis belongs to the branch of bioacoustics and biomechanics. It deals with the modelling of simple analytic models of vocal folds, specifically with their forced oscillation caused by a harmonic excitation force. The thesis also includes an anatomy of the respiratory tract and the vocal system, a description of the principal theories of voice production, and an overview of the vocal folds’ mass models.

Cílem práce je na modelu hlasivky provést analýzu vlivu materiálových parametrů jednotlivých vrstev tkáně hlasivek na šíření slizniční vlny. Nejdříve je na základě literatury uveden stručný přehled současných přístupů při experimentálním a výpočtovém modelování šíření slizniční vlny. Dále je pak pomocí modální analýzy zkoumán vliv modulu pružnosti v tahu epitelu a povrchové laminy proprii na vlastní frekvence a tvary kmitů. Šíření slizniční vlny bylo následně analyzováno pomocí přechodové analýzy jako odezva hlasivky na rázové buzení silou na spodní část hlasivky. Byl vyhodnocován vliv materiálových parametrů na amplitudu a rychlost šíření slizniční vlny po povrchu hlasivky. V závěru práce je uvedeno doporučení, dle zaznamenaných výsledků, použít nižší moduly pružnosti v tahu povrchové laminy proprii v modelech s interakcí s proudem vzduchu, protože je zde mnohem výraznější šíření slizniční vlny odpovídající chování skutečných lidských hlasivek., The aim of this thesis is to analyze the influence of material parameters of individual layers of vocal cord tissue on the propagation of mucosal waves on the vocal cord model. First, a brief overview of current approaches in experimental and computational modeling of mucosal wave propagation is given on the basis of the literature. Furthermore, the influence of the modulus of elasticity in the tensile epithelium and the surface lamina of propria on the natural frequencies and shapes of oscillations is investigated by means of modal analysis. Mucosal wave propagation was then analyzed using transient analysis in response to the vocal cords to shock excitation by force on the lower part of the vocal cords. The influence of material parameters on the amplitude and speed of mucosal wave propagation over the vocal cord surface was evaluated. In the end of this thesis, the recommendation is given, according to the recorded results, to use lower modulus of elasticity in tension of the surface lamina propria in models with interaction with air flow, because there is much more pronounced mucosal wave propagation corresponding to the behavior of real human vocal cords.

Bakalářská práce se zabývá modální analýzou vytvořených výpočtových modelů lidských hlasivek. Jedná se o konečnoprvkový a analytický model, kde hodnoty prvních vlastních frekvencí spadají do rozmezí pro mužské hlasivky. Rešeršní část práce se věnuje biomechanice lidského hlasu, na kterou navazuje přehled výpočtových modelů. Konečnoprvkový model je kompletně vytvořen a vyřešen v komerčním programu ANSYS Workbench, který využívá k simulaci konkrétní úlohy metodu konečných prvků. K řešení analytického modelu se naopak použije volně dostupný programovací jazyk Python. Analýza výsledků a srovnání přístupů patří mezi hlavní cíle předložené práce. Navržený analytický model může sloužit budoucím studentům k detailnějšímu pochopení problematiky kmitání lidských hlasivek., Bachelor’s thesis deals with modal analysis of computed models of human vocal folds. It’s about finite element and analytical model where values first eigenfrequencies come under male vocal folds. Research part applies to biomechanics of vocal the human voice, which is followed by an overview of computational models. Finite element model is completely created and solved by ANSYS Workbench commercial program, which uses the finite element method to simulate a problem. Solution of analytical model uses freely available Python programming language. Analysis of the results and comparison of approaches belong to main objectives of the presented work. The proposed analytical model can serve future students for detailed understanding of human vocal oscillations.

Predložená diplomová práca sa zaoberá výpočtovým modelovaním ľudských hlasiviek pri nastavení do fonačného postavenia pomocou metódy konečných prvkov. V práci je stručne popísaná anatómia hrtanu, teórie objasňujúce princíp tvorby hlasu a prehľad doposiaľ publikovaných výpočtových modelov hlasiviek. Súčasťou práce je úprava geometrie hrtanových chrupaviek a mäkkého tkaniva hlasiviek, vytvorenie siete konečných prvkov a implementácia aktívneho napätia hlasivkového svalu. Úloha bola riešená pomocou softvéru Ansys 19.2. Výpočet napätosti a posuvov tkaniva hlasiviek pri nastavení do fonačného postavenia bol prevedený pre 7 variantov, v ktorých boli zapojené hrtanové chrupavky a aktívne napätie svalu v rôznych kombináciach. Nakoniec bol vyhodnotený vplyv jednotlivých chrupaviek a aktívneho napätia svalu na výslednú napätosť a deformácie mäkkých tkanív hlasiviek., This master‘s thesis deals with computational modelling of human vocal folds in phonation position using finite element method. There are described larynx anatomy, voice generation theories and overview of so far published computational models of vocal folds. Next part of the paper deals with a redesign of vocal folds and soft tissues‘ geometry, creation of finite element mesh and implementation of active stress in thyroarytenoid muscle. The problem was solved using Ansys 19.2 software. Computation of stress and deformation of soft tissues in phonation position has been made for 7 variations with different combination of active cartilages and muscles. Lastly, there was evaluated an effect of different cartilages and active muscle stress to final stress and deformation of soft tissues of vocal folds.

Předložená diplomová práce se zabývá využitím metody konečných prvků pro modelování pohybu a napjatosti hlasivek při nastavování do fonačního postavení. Práce obsahuje popis relevantních anatomických struktur a s tím úzce související tvorby lidského hlasu. Následuje přehled některých dosud publikovaných modelů funkce lidských hlasivek. Součástí práce dále bylo vytvoření modelu geometrie hrtanu pomocí programů CATIA V5 a PTC Creo 2.0 na základě dat pořízených zobrazovací metodou MRI (magnetic resonance imaging). Model byl dále převeden do výpočtového systému Ansys Workbench 15.0 a pro řešení kontaktní úlohy do Ansys Classic 15.0. Tyto programy využívají pro řešení dané úlohy metodu konečných prvků (MKP). Řešení bylo provedeno pro šest variant simulujících jednotlivé pohyby chrupavek odpovídající aktivaci jednotlivých svalů. U jednotlivých variant byly vyhodnoceny posuvy a napětí v měkké tkáni hlasivek. U varianty s aktivací IA, TA a LCA svalu byl také vyhodnocen kontaktní tlak mezi hlasivkami. V neposlední řadě je v práci uvedena příprava modelu pro aktivaci pohybu hlasivek svalstvem hrtanu., This Master´s thesis deals with use of finite element method for modeling motion and stress of vocal folds during setting to phonation position. The thesis contains a description of the relevant anatomical structures and of the closely related formation of the human voice. A list of some previously published models of the function of human vocal folds follows. A part of my work was to create a model of geometry of the larynx using CATIA V5 and PTC Creo 2.0 on the basis of data acquired by MRI (magnetic resonance imaging). After that the model was converted into the calculation system Ansys Workbench 15.0 and, for solving contact problems, into Ansys Classic 15.0. To solve given problems, these programs use the finite element method (FEM). Solution was carried out for six different variants simulating individual motions of cartilages, corresponding to the activation of individual muscles. For each variant, the movements and stresses in the soft tissue of the vocal folds were evaluated. For variants with activation of IA, TA and LCA muscle it was also evaluated the contact pressure between the vocal folds. Finally, the thesis mentions the preparation of the model for the activation of the vocal folds movement by the muscles of the larynx.

Práce se zabývá vytvořením výpočtového modelu funkce lidských hlasivek. Algoritmus výpočtu zahrnuje interakci hlasivek s proudem vzduchu. Součástí práce jsou modální analýzy strukturního a akustického prostředí, rešeržní studie funkce hlasivek a přehled vybraných doposud publikovaných výpočtových modelů. Analýza výsledků dosažených simulačním výpočtovým modelováním se zaměřuje na tlakové a rychlostní poměry pod, mezi a nad hlasivkami, pohyb hlasivek, průběhy napětí v jednotlivých vrstvách hlasivek a posouzení vlivu tloušťky tkání na výsledné chování hlasivek., Master thesis deals with creating numerical model of the human vocal folds. Calculation algorithm includes interaction between vocal chords and the air flow. Modal analysis of structural and acoustic environment, backround research of vocal folds function and summary of some published overviews of numerical models are parts of this work. Analysis of the results achieved by the numerical simulations and calculations are focused on the pressure and velocity conditions in the areas under vocal folds, between vocal folds and above vocal folds. Movement and stress analysis of individual layers of vocal folds has been made. Impact of tissue thickness on resulting behaviour has been assessed.

Následující diplomová práce se zabývá vytvořením výpočtového modelu pro šíření akustických vln lidským vokálním traktem a následně prostorem okolo hlavy člověka. Detailní zmapování akustického pole okolo hlavy člověka je důležité pro zpřesnění měření lidského hlasu. Součástí práce je tvorba trojrozměrného konečně-prvkového modelu lidské hlavy a vokálního traktu při fonaci samohlásky /:a/ na základě dat z výpočtové tomografie, dále rešeršní studie funkce vokálního traktu, biomechanika tvorby lidského hlasu, přehled doposud v literatuře publikovaných výpočtových modelů a v literatuře uváděných měření šíření hlasu lidským vokálním traktem a v prostoru okolo hlavy. Následuje samotné výpočtové řešení šíření akustických vln od hlasivek skrz vokální trakt a prostorem okolo hlavy člověka při uvažování akustické absorpce na stěnách vokálního traktu a na pokožce hlavy pro různé typy buzení. Výsledky jsou porovnány s doposud publikovanými měřeními šíření lidského hlasu a analyzují se hlavně zkreslení frekvenčních spekter v jednotlivých bodech v prostoru okolo hlavy a v její blízkosti kam se obvykle umisťují snímací mikrofony. Výsledků výpočtového modelování bude možné eventuálně využít pro frekvenční korekce pro různé polohy mikrofonů snímající šíření hlasu při jeho diagnostice, řeči nebo zpěvu., The following master thesis deals with creating a computational model for acoustic wave distribution by the human vocal tract and then the space around a human head. Detailed mapping of the sound field around the human head is important for more accurate measurement of the human voice. Part of this work is the creation of three-dimensional finite element model of the human head and the vocal tract during phonation of the vowel /:a/ based on the data from the computational tomography. Further the literature search of the function of the vocal tract, biomechanics of the making of the human voice, an overview of the computational models so far published in the literature and in literature reported measurements of the distribution of the human voice by the vocal tract and then in the space around the head . The following is the actual numerical solution of the acoustic waves distribution from the vocal cords through the vocal tract and then the space around the human head when thinking of acoustic absorption on the walls of the vocal tract and on the skin of the head for different types of waking of the model. The results are compared with previously published measurements of the distribution of the human voice and mainly the distortion of the frequency spectra at each specific node in the space around the head and in its vicinity of where the sensor microphones are typically placed are analyzed. Results of the computational modeling will eventually be used for frequency correction for various positions of the microphones scanning the voice distribution in its diagnosis, speech or singing.