Vocal nodules and edema may be due to vibration-induced rises in capillary pressure

Immediate Impact of Vocal Demand, Likelihood of Dysphonia, and Performance Aspects in Amateur Protestant Singers

OBJECTIVES

To analyze the immediate impact of vocal demand, probability of dysphonia, and performance aspects in amateur protestant singers.

METHODS

Cross-sectional, analytical study, with 76 amateur singers from a protestant church, 60 women and 16 men. All participants responded to a sociodemographic and performance questionnaire, the Evaluation of the Ability to Sing Easily for Brazil (EASE-BR), and the Dysphonia Screening Tool (DST-Br). The data were analyzed descriptively and inferentially, considering a significance level of 5%.

RESULTS

The singers reported good voice status after a performance, with the possibility of singing again if necessary. Most individuals had a low probability of dysphonia, showing a lower mean score compared to those with a moderate probability. There was an association between "trying to sing louder than others" and "vocal self-assessment" with the immediate impact of vocal demand and dysphonia screening. Implementing vocal rest was significantly associated with EASE-BR, and trying to sing louder than the instruments and being able to hear yourself well while singing and water intake were associated with the total DST-Br score.

CONCLUSIONS

The immediate impact of vocal demand after performance on this population did not compromise their ability to sing easily. Most singers had a low probability of dysphonia. "Trying to sing louder than the instruments" and "ability to hear oneself well while singing and water intake" were associated with dysphonia screening.

The effect of swelling on vocal fold kinematics and dynamics

Swelling in the vocal folds is caused by the local accumulation of fluid, and has been implicated as a phase in the development of phonotraumatic vocal hyperfunction and related structural pathologies, such as vocal fold nodules. It has been posited that small degrees of swelling may be protective, but large amounts may lead to a vicious cycle wherein the engorged folds lead to conditions that promote further swelling, leading to pathologies. As a first effort to explore the mechanics of vocal fold swelling and its potential role in the etiology of voice disorders, this study employs a finite-element model with swelling confined to the superficial lamina propria, which changes the volume, mass, and stiffness of the cover layer. The impacts of swelling on a number of vocal fold kinematic and damage measures, including von Mises stress, internal viscous dissipation, and collision pressure, are presented. Swelling has small but consistent effects on voice outputs, including a reduction in fundamental frequency with increasing swelling (10 Hz at 30 % swelling). Average von Mises stress decreases slightly for small degrees of swelling but increases at large magnitudes, consistent with expectations for a vicious cycle. Both viscous dissipation and collision pressure consistently increase with the magnitude of swelling. This first effort at modeling the impact of swelling on vocal fold kinematics, kinetics, and damage measures highlights the complexity with which phonotrauma can influence performance metrics. Further identification and exploration of salient candidate measures of damage and refined studies coupling swelling with local phonotrauma are expected to shed further light on the etiological pathways of phonotraumatic vocal hyperfunction.

Are Children with Cleft Palate at Increased Risk for Laryngeal Pathology?

To determine the prevalence of laryngeal pathology in children presenting with cleft palate with or without cleft lip (CP ± L) who underwent nasoendoscopy to assess palatal function. A secondary aim was to determine the relationship between patient demographics, resonance, articulation, and prevalence of laryngeal pathology in this population.

Retrospective, observational cohort study.

Outpatient pediatric cranio-facial anomalies clinic.

Children ≤18 years of age presenting with CP ± L (N = 215) who underwent nasoendoscopy, speech language pathology, plastic surgery, and otolaryngological evaluations between 2009 and 2020.

Laryngeal diagnosis by pediatric otolaryngologists.

21.9% of children presented with laryngeal pathology. Diagnoses included benign vocal fold lesions and laryngeal edema sufficiently severe to alter vocal fold edge contour. Likelihood of laryngeal pathology increased by approximately 12% with every increase of 1 year in age (P = .001, OR = 1.12). Children with laryngeal pathology were 50% more likely to have undergone palatal repair (P < .001, OR = 1.50). In addition, children with severely hypernasal resonance were 78% less likely to present with laryngeal pathology (P =.046, OR = 0.22).

This population is at increased risk for laryngeal pathologies as determined by nasoendoscopy. This finding underscores the importance of careful laryngeal imaging in assessing these children. Additional research is warranted to identify the mechanisms underlying the increased risk for morphological vocal fold changes.

The Added Value of Steroid Injection Following Office-based Blue Laser Therapy of Benign Lesions of the Vocal Folds; Short-Term Effect in a Cohort of 43 Patients

OBJECTIVES

To investigate the added value of steroid injection following office-based blue laser therapy of benign lesions of the vocal folds.

STUDY DESIGN

Retrospective cohort analysis.

METHODS

The medical records and video-recordings of patients with benign lesions of the vocal folds who underwent office-based blue laser therapy in a tertiary referral center between February 2020 and October 2022 were reviewed. Patients were divided into two subgroups, those who underwent office-based blue laser therapy alone (n = 23) and those who underwent office-based blue laser therapy with steroid injection (n = 19). Disease regression and voice outcome measures included Voice Handicap Index-10 score, perceptual voice evaluation using the GRB grading, jitter, shimmer, noise to harmonic ratio, voice turbulence index, and maximum phonation time were reviewed.

RESULTS

A total of 42 patients were included. The mean age was 54.7 ± 10.1 years. Lesions included polyps (n = 21), Reinke's edema (n = 19), and cysts (n = 2). There was partial or complete disease regression in all patients who presented for follow-up (n = 37). In patients who underwent blue laser therapy alone (n = 19), 42.1% had complete regression and 57.9% had partial regression. In those who underwent blue laser therapy followed by steroid injection (n = 18), 77.7% had complete disease regression and 22.3% had partial regression. The difference in disease regression between the two subgroups was statistically significant (P = 0.027). The decrease in the mean Voice Handicap Index-10 score was also statistically significant with a higher mean being noted in the subgroup who underwent blue laser therapy followed by steroid injection (-10.5 ± 6.9 vs. -17.3 ± 11.8, P = 0.031). There was no significant difference in the decrease in the perceptual evaluation scores nor in the decrease in jitter, shimmer, noise to harmonic ratio, and voice turbulence index between the two subgroups. There was also no significant increase in the maximum phonation time.

CONCLUSION

Steroid injection after blue laser therapy improves disease regression and voice outcome of laser therapy.

Membranous Vocal Fold Lesions in Patients With Chronic Cough: A Case Series

OBJECTIVES

Trauma related to chronic cough and forceful glottal closure has been associated with lesions of the vocal process; however, there is limited description of cough leading to membranous vocal fold lesions. We present a series of mid-membranous vocal fold lesions in a cohort of patients with chronic cough, with a proposed mechanism of lesion formation.

METHODS

Patients treated for chronic cough with membranous vocal fold lesions affecting phonation were identified. Presentation, diagnosis, treatment strategies (behavioral, medical, and surgical), patient-reported outcome measures (PROMs), and videostroboscopy were reviewed.

RESULTS

Five patients are included (four females, one male, aged 56±16 years). Mean cough duration was 2.6±3.5 years. All patients were on acid suppressive medications for existing gastroesophageal reflux disease (GERD) prior to referral. All lesions were identified at the mid-membranous vocal folds and morphologically encompassed a wound healing spectrum between ulceration and/or granulation tissue (granuloma) formation. Patients were treated in an interdisciplinary fashion with behavioral cough suppression therapy, superior laryngeal nerve block, and neuromodulators. Three had persistent lesions requiring procedural intervention (one office-based steroid injection and two surgical excisions). At the completion of treatment, all five patients had improvement in Cough Severity Index with an average decrease of 15.2±4.8. All but one patient had improvement in their Voice Handicap Index-10 with an average decrease of 13.2±11.1. One patient undergoing surgical intervention was noted to have a persistent lesion on follow-up.

CONCLUSION

Mid-membranous vocal fold lesions in patients with chronic cough are uncommon. When they do occur, they represent epithelial change arising in context of shear injury and are distinct from phonotraumatic lesions in the lamina propria. An interdisciplinary approach including behavioral cough suppression therapy, neuromodulators, superior laryngeal nerve block, and acid suppression are reasonable for initial management, reserving surgical intervention for refractory lesions once the inciting source of injury has been controlled.

Voice efficiency for different voice qualities combining experimentally derived sound signals and numerical modeling of the vocal tract

Purpose: Concerning voice efficiency considerations of different singing styles, from western classical singing to contemporary commercial music, only limited data is available to date. This single-subject study attempts to quantify the acoustic sound intensity within the human glottis depending on different vocal tract configurations and vocal fold vibration. Methods: Combining Finite-Element-Models derived from 3D-MRI data, audio recordings, and electroglottography (EGG) we analyzed vocal tract transfer functions, particle velocity and acoustic pressure at the glottis, and EGG-related quantities to evaluate voice efficiency at the glottal level and resonance characteristics of different voice qualities according to Estill Voice Training®. Results: Voice qualities Opera and Belting represent highly efficient strategies but apply different vowel strategies and should thus be capable of predominate orchestral sounds. Twang and Belting use similar vowels, but the twang vocal tract configuration enabled the occurrence of anti-resonances and was associated with reduced vocal fold contact but still partially comparable energy transfer from the glottis to the vocal tract. Speech was associated with highly efficient glottal to vocal tract energy transfer, but with the absence of psychoactive strategies makes it more susceptible to noise interference. Falsetto and Sobbing apply less efficiently. Falsetto mainly due to its voice source characteristics, Sobbing due to energy loss in the vocal tract. Thus technical amplification might be appropriate here. Conclusion: Differences exist between voice qualities regarding the sound intensity, caused by different vocal tract morphologies and oscillation characteristics of the vocal folds. The combination of numerical analysis of geometries inside the human body and experimentally determined data outside sheds light on acoustical quantities at the glottal level.

A Study on Comparison of Conventional Micro Laryngeal Micro Dissection Surgery with Carbon Dioxide Laser in Management of Benign Lesions of Larynx

Dysphonia is a common symptom in benign and pre malignant lesions of larynx affecting vocal cords. Surgical excision is the main stay of treatment. Only a limited number of studies have compared the efficacy of microdissection versus CO2 laser surgery in the larynx. In the present study we have compared conventional micro-laryngeal surgery and carbon dioxide laser assisted microsurgical technique in the management of these lesions. A randomized prospective study was conducted in 88 cases of benign and pre malignant lesions affecting vocal cords were divided randomly to undergo surgery either by conventional micro dissection or CO2 laser assisted techniques in a tertiary care hospital. The groups were assessed through vocal cord morphological observation by videostroboscopy and subjective voice assessment parameters GRBAS score and VHI10 index preoperatively and 2 weeks and 3 months postoperatively by a panel of blinded viewers and listeners. Surgical and recovery times were compared between the two groups. Intraoperative blood loss was compared by gauze visual analogue. Patients recovered remarkably well following both the techniques as denoted by the voice parameters. Peroperative bleeding was observed to be significantly reduced in the laser excision group; operating time was significantly increased in this group. Duration of hospital stay was similar in both groups. No differences in clinical outcomes are identified when comparing microdissection with laser excision of benign lesions.

Amount and Characteristics of Speaking and Singing Voice Use in Vocally Healthy Female College Student Singers During a Typical Week

OBJECTIVES

Singers, college students, and females are groups known to be at an elevated risk of developing functional/hyperfunctional voice disorders; therefore, female college students majoring in vocal performance may be at an even higher risk. To mitigate this risk, it would be helpful to know the "safe limits" for voice use that would help maintain vocal health in this vulnerable group, but there is a paucity of high-quality objective information upon which to base such limits. This study employed weeklong ambulatory voice monitoring in a large group of vocally healthy female college student singers to begin providing the types of objective data that could be used to help develop improved vocal health guidelines.

METHODS

Participants included 64 vocally healthy females currently enrolled in a vocal performance or similar program at a college or university. An ambulatory voice monitor recorded neck-surface acceleration throughout a typical week. A singing classifier was applied to the data to separate singing from speech. Weeklong vocal dose measures and distributional characteristics for standard voice measures were computed separately for singing and speech, and for both types of phonation combined.

RESULTS

Participants spent 6.2% of the total monitoring time speaking and 2.1% singing (with total phonation time being 8.4%). Singing had a higher f_o mode, more pitch variability, higher average sound pressure level (SPL), negatively skewed SPL distributions, lower average CPP, and higher H₁-H₂ values than speaking.

CONCLUSIONS

These results provide a basis for beginning to establish vocal health guidelines for female students enrolled in college-level vocal performance programs and for future studies of the types of voice disorders that are common in this group. Results also demonstrate the potential value that ambulatory voice monitoring may have in helping to objectively identify vocal behaviors that could contribute to voice problems in this population.

Direct measurement and modeling of intraglottal, subglottal, and vocal fold collision pressures during phonation in an individual with a hemilaryngectomy

The purpose of this paper is to report on the first in vivo application of a recently developed transoral, dual-sensor pressure probe that directly measures intraglottal, subglottal, and vocal fold collision pressures during phonation. Synchronous measurement of intraglottal and subglottal pressures was accomplished using two miniature pressure sensors mounted on the end of the probe and inserted transorally in a 78-year-old male who had previously undergone surgical removal of his right vocal fold for treatment of laryngeal cancer. The endoscopist used one hand to position the custom probe against the surgically medialized scar band that replaced the right vocal fold and used the other hand to position a transoral endoscope to record laryngeal high-speed videoendoscopy of the vibrating left vocal fold contacting the pressure probe. Visualization of the larynx during sustained phonation allowed the endoscopist to place the dual-sensor pressure probe such that the proximal sensor was positioned intraglottally and the distal sensor subglottally. The proximal pressure sensor was verified to be in the strike zone of vocal fold collision during phonation when the intraglottal pressure signal exhibited three characteristics: an impulsive peak at the start of the closed phase, rounded peak during the open phase, and minimum value around zero immediately preceding the impulsive peak of the subsequent phonatory cycle. Numerical voice production modeling was applied to validate model-based predictions of vocal fold collision pressure using kinematic vocal fold measures. The results successfully demonstrated feasibility of in vivo measurement of vocal fold collision pressure in an individual with a hemilaryngectomy, motivating ongoing data collection that is designed to aid in the development of vocal dose measures that incorporate vocal fold impact collision and stresses.

Study of spatiotemporal liquid dynamics in a vibrating vocal fold by using a self-oscillating poroelastic model

The main purpose of this study is to investigate the spatiotemporal interstitial fluid dynamics in a vibrating vocal fold. A self-oscillating poroelastic model is proposed to study the liquid dynamics in the vibrating vocal folds by treating the vocal fold tissue as a transversally isotropic, fluid-saturated, porous material. Rich spatiotemporal liquid dynamics have been found. Specifically, in the vertical direction, the liquid is transported from the inferior side to the superior side due to the propagation of the mucosal wave. In the longitudinal direction, the liquid accumulates at the anterior-posterior midpoint. However, the contact between the two vocal folds forces the accumulated liquid out laterally in a very short time span. These findings could be helpful for exploring etiology of some laryngeal pathologies, optimizing laryngeal disease treatment, and understanding hemodynamics in the vocal folds.

Estimation of Subglottal Pressure From Neck Surface Vibration in Patients With Voice Disorders

Purpose Given the established linear relationship between neck surface vibration magnitude and mean subglottal pressure (Ps) in vocally healthy speakers, the purpose of this study was to better understand the impact of the presence of a voice disorder on this baseline relationship. Method Data were obtained from participants with voice disorders representing a variety of glottal conditions, including phonotraumatic vocal hyperfunction, nonphonotraumatic vocal hyperfunction, and unilateral vocal fold paralysis. Participants were asked to repeat /p/-vowel syllable strings from loud-to-soft loudness levels in multiple vowel contexts (/pa/, /pi/, /pu/) and pitch levels (comfortable, higher than comfortable, lower than comfortable). Three statistical metrics were computed to analyze the regression line between neck surface accelerometer (ACC) signal magnitude and Ps within and across pitch, vowel, and voice disorder category: coefficient of determination (r 2), slope, and intercept. Three linear mixed-effects models were used to evaluate the impact of voice disorder category, pitch level, and vowel context on the relationship between ACC signal magnitude and Ps. Results The relationship between ACC signal magnitude and Ps was statistically different in patients with voice disorders than in vocally healthy controls; patients exhibited higher levels of Ps given similar values of ACC signal magnitude. Negligible effects were found for pitch condition within each voice disorder category, and negligible-to-small effects were found for vowel context. The mean of patient-specific r 2 values was .63, ranging from .13 to .92. Conclusions The baseline, linear relationship between ACC signal magnitude and Ps is affected by the presence of a voice disorder, with the relationship being participant-specific. Further work is needed to improve ACC-based prediction of Ps, across treatment, and during naturalistic speech production.

Ovine Vocal Fold Tissue Fatigue Response to Accumulated, Large-Amplitude Vibration Exposure at Phonatory Frequencies

Purpose The contribution of tissue mechanical response to vocal fatigue is poorly understood. This study investigated the fatigue response of vocal fold tissues to large-amplitude vibration exposure at phonatory frequencies, using an ex vivo ovine model. Method Twelve sheep vocal fold mucosal specimens were subjected to sinusoidal, simple-shear deformation for prolonged cycles, under a large but physiological shear strain (46%) in a frequency range of 100-230 Hz. The duration of shear varied from a critical vibration exposure limit of 1,040 s to 4 times the limit (4,160 s). Tissue viscoelastic response was quantified by the elastic shear modulus (G'), viscous shear modulus (G″), and damping ratio (G″/G'). Results Distinct response patterns were observed at different frequencies. G' and G″ generally decreased with vibration exposure at 100 Hz, whereas they generally increased with vibration exposure at 200 and 230 Hz. Statistically significant differences were found for G″ increasing with vibration exposure at 200 Hz and damping ratio decreasing with vibration exposure at 200 Hz. Significant increases with frequency were also found for all viscoelastic functions. Results suggested that the contribution of tissue viscoelastic response to vocal fatigue could be highly frequency dependent. In particular, increases in G″ with vibration exposure could lead to high phonation threshold pressures and difficulty sustaining phonation at higher frequencies following prolonged vocalization. Conclusion These preliminary findings may help us better understand vocal fatigue and recovery and should be corroborated by studies with human vocal fold tissues.

Toward Development of a Vocal Fold Contact Pressure Probe: Bench-Top Validation of a Dual-Sensor Probe Using Excised Human Larynx Models

A critical element in understanding voice production mechanisms is the characterization of vocal fold collision, which is widely considered a primary etiological factor in the development of common phonotraumatic lesions such as nodules and polyps. This paper describes the development of a transoral, dual-sensor intraglottal/subglottal pressure probe for the simultaneous measurement of vocal fold collision and subglottal pressures during phonation using two miniature sensors positioned 7.6 mm apart at the distal end of a rigid cannula. Proof-of-concept testing was performed using excised whole-mount and hemilarynx human tissue aerodynamically driven into self-sustained oscillation, with systematic variation of the superior-inferior positioning of the vocal fold collision sensor. In the hemilarynx experiment, signals from the pressure sensors were synchronized with an acoustic microphone, a tracheal-surface accelerometer, and two high-speed video cameras recording at 4000 frames per second for top-down and en face imaging of the superior and medial vocal fold surfaces, respectively. As expected, the intraglottal pressure signal exhibited an impulse-like peak when vocal fold contact occurred, followed by a broader peak associated with intraglottal pressure build-up during the de-contacting phase. As subglottal pressure was increased, the peak amplitude of the collision pressure increased and typically reached a value below that of the average subglottal pressure. Results provide important baseline vocal fold collision pressure data with which computational models of voice production can be developed and in vivo measurements can be referenced.

Estimating Vocal Fold Contact Pressure from Raw Laryngeal High-Speed Videoendoscopy Using a Hertz Contact Model

The development of trauma-induced lesions of the vocal folds (VFs) has been linked to a high collision pressure on the VF surface. However, there are no direct methods for the clinical assessment of VF collision, thus limiting the objective assessment of these disorders. In this study, we develop a video processing technique to directly quantify the mechanical impact of the VFs using solely laryngeal kinematic data. The technique is based on an edge tracking framework that estimates the kinematic sequence of each VF edge with a Kalman filter approach and a Hertzian impact model to predict the contact force during the collision. The proposed formulation overcomes several limitations of prior efforts since it uses a more relevant VF contact geometry, it does not require calibrated physical dimensions, it is normalized by the tissue properties, and it applies a correction factor for using a superior view only. The proposed approach is validated against numerical models, silicone vocal fold models, and prior studies. A case study with high-speed videoendoscopy recordings provides initial insights between the sound pressure level and contact pressure. Thus, the proposed method has a high potential in clinical practice and could also be adapted to operate with laryngeal stroboscopic systems.

A method to directly estimate the contact pressure of the vocal folds using uncalibrated laryngeal kinematic data is presented. The approach is promising in enhancing the objective assessment of vocal function in clinical settings, especially for studying same-subject variations.

Quantifying Vocal Fatigue Recovery: Dynamic Vocal Recovery Trajectories after a Vocal Loading Exercise

Objectives

We quantified the recovery of voice following a 2-hour vocal loading exercise (oral reading).

Methods

Eighty-six adult participants tracked their voice recovery using short vocal tasks and perceptual ratings after an initial vocal loading exercise and for the following 2 days.

Results

Short-term recovery was apparent, with 90% recovery within 4 to 6 hours and full recovery at 12 to 18 hours. Recovery was shown to be similar to a dermal wound healing trajectory.

Conclusions

The new recovery trajectory highlighted by the vocal loading exercise in the current study is called a vocal recovery trajectory. By comparing vocal fatigue to dermal wound healing, this trajectory is parallel to a chronic wound healing trajectory (as opposed to an acute wound healing trajectory). This parallel suggests that vocal fatigue from the daily use of the voice could be treated as a chronic wound, with the healing and repair mechanisms in a state of constant repair. In addition, there is likely a vocal fatigue threshold at which point the level of tissue damage would shift the chronic healing trajectory to an acute healing trajectory.

Ambulatory Voice Biofeedback: Relative Frequency and Summary Feedback Effects on Performance and Retention of Reduced Vocal Intensity in the Daily Lives of Participants With Normal Voices

Purpose

Ambulatory voice biofeedback has the potential to significantly improve voice therapy effectiveness by targeting carryover of desired behaviors outside the therapy session (i.e., retention). This study applies motor learning concepts (reduced frequency and delayed, summary feedback) that demonstrate increased retention to ambulatory voice monitoring for training nurses to talk softer during work hours.

Method

Forty-eight nurses with normal voices wore the Voice Health Monitor (Mehta, Zañartu, Feng, Cheyne, & Hillman, 2012) for 6 days: 3 baseline days, 1 biofeedback day, 1 short-term retention day, and 1 long-term retention day. Participants were block-randomized into 3 different biofeedback groups: 100%, 25%, and Summary. Performance was measured in terms of compliance time below a participant-specific vocal intensity threshold.

Results

All participants exhibited a significant increase in compliance time (Cohen's d = 4.5) during biofeedback days compared with baseline days. The Summary feedback group exhibited statistically smaller performance reduction during both short-term (d = 1.14) and long-term (d = 1.04) retention days compared with the 100% feedback group.

Conclusions

These findings suggest that modifications in feedback frequency and timing affect retention of a modified vocal behavior in daily life. Future work calls for studying the potential beneficial impact of ambulatory voice biofeedback in participants with behaviorally based voice disorders.

Over-vibration induced blood perfusion and vascular permeability changes may lead to vocal edema

OBJECTIVES/HYPOTHESIS

To observe blood perfusion and vascular permeability changes under varying vibration frequency exposures.

STUDY DESIGN

Animal model.

METHODS

Blood perfusion was measured using laser Doppler flowmetry in eight rabbit auricular vessels (four rabbits) under nonvibration, and 62.5-Hz/1-mm, 125-Hz/1-mm, and 250-Hz/0.5-mm vibration frequency/amplitude exposures. Another 12 rabbits were randomly divided into vibration only and vibration with histamine groups. After 3 hours of continuous 125-Hz, 1-mm amplitude vibration of the auricle, vascular permeability was analyzed by absorbance of Evans blue-albumin complex.

RESULTS

Significantly lower blood perfusion was observed in the vibration group, compared with no vibration exposure controls. Blood perfusion decreased 29 ± 16% as the vibration frequency was increased from 62.5 Hz to 125 Hz with the vibration amplitude constant at 1 mm. When the frequency was increased from 125 Hz to 250 Hz, while the amplitude was decreased from 1 mm to 0.5 mm, blood flow perfusion further decreased 29 ± 29%, and the decline tendency in blood perfusion showed no significant difference (P = .992). Meanwhile, in the vibration with histamine group, vascular permeability of the vibrated ears increased significantly compared to the nonvibrated ears (P = .005).

CONCLUSIONS

Overvibration of the vocal folds due to voice overuse or abuse may significantly reduce blood perfusion, and increase vascular permeability in the vocal fold in inflammatory situations, which may lead to the formation of vocal edema.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:148-152, 2017.

Using Ambulatory Voice Monitoring to Investigate Common Voice Disorders: Research Update

Many common voice disorders are chronic or recurring conditions that are likely to result from inefficient and/or abusive patterns of vocal behavior, referred to as vocal hyperfunction. The clinical management of hyperfunctional voice disorders would be greatly enhanced by the ability to monitor and quantify detrimental vocal behaviors during an individual’s activities of daily life. This paper provides an update on ongoing work that uses a miniature accelerometer on the neck surface below the larynx to collect a large set of ambulatory data on patients with hyperfunctional voice disorders (before and after treatment) and matched-control subjects. Three types of analysis approaches are being employed in an effort to identify the best set of measures for differentiating among hyperfunctional and normal patterns of vocal behavior: (1) ambulatory measures of voice use that include vocal dose and voice quality correlates, (2) aerodynamic measures based on glottal airflow estimates extracted from the accelerometer signal using subject-specific vocal system models, and (3) classification based on machine learning and pattern recognition approaches that have been used successfully in analyzing long-term recordings of other physiological signals. Preliminary results demonstrate the potential for ambulatory voice monitoring to improve the diagnosis and treatment of common hyperfunctional voice disorders.

Average Ambulatory Measures of Sound Pressure Level, Fundamental Frequency, and Vocal Dose Do Not Differ Between Adult Females With Phonotraumatic Lesions and Matched Control Subjects

OBJECTIVES

Clinical management of phonotraumatic vocal fold lesions (nodules, polyps) is based largely on assumptions that abnormalities in habitual levels of sound pressure level (SPL), fundamental frequency (f0), and/or amount of voice use play a major role in lesion development and chronic persistence. This study used ambulatory voice monitoring to evaluate if significant differences in voice use exist between patients with phonotraumatic lesions and normal matched controls.

METHODS

Subjects were 70 adult females: 35 with vocal fold nodules or polyps and 35 age-, sex-, and occupation-matched normal individuals. Weeklong summary statistics of voice use were computed from anterior neck surface acceleration recorded using a smartphone-based ambulatory voice monitor.

RESULTS

Paired t tests and Kolmogorov-Smirnov tests resulted in no statistically significant differences between patients and matched controls regarding average measures of SPL, f0, vocal dose measures, and voicing/voice rest periods. Paired t tests comparing f0 variability between the groups resulted in statistically significant differences with moderate effect sizes.

CONCLUSIONS

Individuals with phonotraumatic lesions did not exhibit differences in average ambulatory measures of vocal behavior when compared with matched controls. More refined characterizations of underlying phonatory mechanisms and other potentially contributing causes are warranted to better understand risk factors associated with phonotraumatic lesions.

Characterizing liquid redistribution in a biphasic vibrating vocal fold using finite element analysis

OBJECTIVES

Vocal fold tissue is biphasic and consists of a solid extracellular matrix skeleton swelled with interstitial fluid. Interactions between the liquid and solid impact the material properties and stress response of the tissue. The objective of this study was to model the movement of liquid during vocal fold vibration and to estimate the volume of liquid accumulation and stress experienced by the tissue near the anterior-posterior midline, where benign lesions are observed to form.

METHODS

A three-dimensional biphasic finite element model of a single vocal fold was built to solve for the liquid velocity, pore pressure, and von Mises stress during and just after vibration using the commercial finite element software COMSOL Multiphysics (Version 4.3a, 2013, Structural Mechanics and Subsurface Flow Modules). Vibration was induced by applying direct load pressures to the subglottal and intraglottal surfaces. Pressure ranges, frequency, and material parameters were chosen based on those reported in the literature. Postprocessing included liquid velocity, pore pressure, and von Mises stress calculations as well as the frequency-stress and amplitude-stress relationships.

RESULTS

Resulting time-averaged velocity vectors during vibration indicated liquid movement toward the midline of the fold, as well as upward movement in the inferior-superior direction. Pore pressure and von Misses stresses were higher in this region just after vibration. A linear relationship was found between the amplitude and pore pressure, whereas a nonlinear relationship was found between the frequency and pore pressure.

CONCLUSIONS

Although this study had certain computational simplifications, it is the first biphasic finite element model to use a realistic geometry and demonstrate the ability to characterize liquid movement due to vibration. Results indicate that there is a significant amount of liquid that accumulates at the midline; however, the role of this accumulation still requires investigation. Further investigation of these mechanical factors may lend insight into the mechanism of benign lesion formation.

Permeability of canine vocal fold lamina propria

OBJECTIVES/HYPOTHESIS

Determine the permeability of excised canine vocal fold lamina propria.

STUDY DESIGN

Basic science.

METHODS

Vocal folds were excised from canine larynges and mounted within a device to measure the flow of 0.9% saline through the tissue over time. The resultant fluid volume displaced over time was then used in a variation of Darcy's law to calculate the permeability of the tissue. Permeability was found through each anatomical plane of the vocal fold, with five samples per plane. Permeability was also found for lamina propria stretched to 10%, 20%, and 30% of its initial length to determine the effects of tensile strain on permeability, with five samples per level of strain.

RESULTS

Permeability was found to be 1.40 × 10(-13) m(3) s/kg through the sagittal plane, 1.00 × 10(-13) m(3) s/kg through the coronal plane, and 4.02 × 10(-13) m(3) s/kg through the axial plane. It was significantly greater through the axial plane than both the sagittal (P = .025) and coronal (P = .009) planes. Permeability under strain through the sagittal plane was found to be 1.94 × 10(-13) m(3) s/kg under 10% strain, 3.35 × 10(-13) m(3) s/kg under 20% strain, and 4.80 × 10(-13) m(3) s/kg under 30% strain. The permeability significantly increased after 20% strain (P < .05).

CONCLUSIONS

Permeability in canine vocal fold lamina propria was found to be increased along the anterior-posterior axis, following the length of the vocal folds. This may influence fluid distribution within the lamina propria during and after vibration. Similarly, permeability increased after 20% strain was imposed on the lamina propria, and may influence vocal fold dynamics during certain phonation tasks.

LEVEL OF EVIDENCE

NA Laryngoscope, 125:941-945, 2015.

Síndrome de tensão musculoesquelética, musculatura laríngea extrínseca e postura corporal: considerações teóricas

O tema deste estudo é a Síndrome de tensão musculoesquelética, musculatura laríngea extrínseca e postura corporal. Tem como objetivo descrever, a partir de revisão de literatura,as características da musculatura extrínseca da laringe; postura corporal; Síndrome de tensão musculoesquelética e suas implicações vocais; avaliação e tratamento fisioterapêutico e fonoaudiológico. Foi realizado levantamento bibliográfico dos últimos 13 anos em que foram incluídos artigos cujo objetivo e/ou corpo do texto estivessem em consonância com os objetivos do estudo. A pesquisa foi realizada nos bancos de dados das bases Literatura Latino-Americana e do Caribe em Ciências da Saúde, Biblioteca Regional de Medicina, PublicMedline, Medical Literature Analysis and Retrieval System on Line, Scientific Electronic Library Online e Google Schoolar. Estabeleceram-se relações importantes do âmbito fisioterapêutico e fonoaudiológico, dentre as quais se destacam as relações musculares, posturais e funcionais na sinergia do aparato vocal. Na fisioterapia para redução da tensão muscular, a literatura aponta uso de eletroterapia transcutânea, laser de baixa intensidade, laser acupuntura, crioterapia, bem como terapia manual com tração, massagens, manipulações e mobilizações cervicais, associadas ou não a exercícios, alongamentos, relaxamento isométrico, mobilização assistida dos tecidos moles, exercícios terapêuticos visando à correção e equilíbrio muscular, reeducação respiratória diafragmática e terapia com flexão craniocervical. Na fonoaudiologia, foram encontrados apenas estudos com a manipulação digital da laringe e exercícios de trato vocal semiocluído.

Perceptual and acoustic parameters of vocal nodules in children

Vocal nodules constitute the major cause of dysphonia during childhood. Auditory-perceptual and acoustic vocal analyses have been used to differentiate vocal nodules from normal voice in children.

PURPOSE

To study the value of auditory-perceptual and acoustic vocal analyses in assessments of children with nodules.

DESIGN

Diagnostic test study.

PATIENTS AND INTERVENTIONS

A comparative study was carried out including 100 children with videolaryngoscopic diagnosis of vocal nodules (nodule group-NG); and 100 children without vocal symptoms and with normal videolaryngoscopic exams (control group-CG). The age range of both groups was between 4 and 11 years. All children underwent auditory-perceptual vocal analyses (GRBASI scale); maximum phonation time and s/z ratio were calculated, and acoustic vocal analysis (MDVP software) were carried out.

RESULTS

There was no difference in the values of maximum phonation time and s/z ratio between groups. Auditory-perceptual analysis indicated greater compromising of voice parameters for NG, compared to CG: G (79 versus 24), R (53 versus 3), B (67 versus 23) and S (35 versus 1). The values of acoustic parameters jitter, PPQ, shimmer, APQ, NHR and SPI were higher for NG for CG. The parameter f0 did not differ between groups.

CONCLUSION

Compromising of auditory-perceptual (G, R, B and S) and acoustic vocal parameters (jitter, PPQ, shimmer, APQ, NHR and SPI) was greater for children with nodules than for those of the control group, which makes them important methods for assessing child dysphonia.

Clinical practice: vocal nodules in dysphonic children

Common among children, vocal symptoms are a cause of concern for parents who seek elucidation of their diagnosis and treatment. Vocal nodules are the major cause of dysphonias in children and are related to vocal abuse. We conducted a literature review considering clinical, physiopathological, epidemiological, and histological aspects of vocal nodules, as well as diagnostic methods, highlighting the main studies addressing this issue. The controversial points of treatments were also discussed.

Jugular vein phlebectasia in paediatric patients with vocal fold nodules

Jugular vein phlebectasia (JVP) may often be overlooked in clinical practice and the management for JVP include surgery and a conservative approach. We have studied the relationship between JVP and vocal fold nodules in paediatric patients as well as the effects of treatment. Twenty-three cases of paediatric vocal fold nodules with JVP were studied. All patients received voice therapy. After 6 months of treatment, hoarseness, neck appearance (subjective evaluation) and the degree of dilation of the jugular vein detected by Doppler ultrasonography were analysed. The follow-up period was 6 to 84 months. The hoarseness disappeared or lessened noticeably after treatment for 1-4 months. The neck masses also lessened (pre vs. post: 2.58 ± 0.40 vs. 1.60 ± 0.19) after treatment for 1-4 months. The visual analogue score of the post-treatment symptoms decreased significantly compared with pre-treatment (p <0.05). The degree of dilation of the post-treatment jugular vein also decreased significantly (p <0.05).

CONCLUSION

Paediatric vocal fold nodules may be related to JVP. Voice changes may also be observed in cases of paediatric JVP. Voice therapy may offer another conservative treatment option for JVP accompanied by vocal fold nodules, and it may offer better results than simple observation of JVP.

Morphological and Histological Changes of Rabbit Vocal Fold after Steroid Injection

Objectives/Hypothesis

The purpose of this study was to investigate the morphological and histological change of vocal folds (VFs) after steroid injection in a rabbit model.

Study Design

Prospective animal study.

Setting

Tertiary academic medical center.

Subjects and Methods

Twenty-four New Zealand white rabbits were used in this study. We randomly classified rabbits into the 3 groups and triamcinolone acetonide suspension was injected to the right VF with different concentrations. Left VF was injected with the same volume of phosphate-buffered saline as control. Endoscopic evaluation was performed to measure morphological changes. The larynges were collected for histological analysis, and the VFs were stained with hematoxylin-eosin for assessing inflammatory response, glandular atrophy, and muscular atrophy and with Masson’s trichrome for assessing collagen deposition.

Results

In morphological assessment, there were no differences in VF mass reduction, mucosal atrophy, and granulation formation between both VFs. Histological assessments showed no significant difference in inflammatory response, glandular atrophy, and collagen deposition between both VFs. However, there was a difference in muscular atrophy and epithelial layer thinning in steroid injected right VFs. Muscular atrophy had been completely recovered over time, but mild epithelial thinning was continued until 12 weeks. The longer exposure time and larger dose did not increase the intensity of muscular atrophy or epithelial thinning.

Conclusion

We demonstrated that the VF steroid injection resulted in no significant changes in morphology and histology of rabbit VF. However, steroid injection may induce several VF histological changes and these results are needed to be considered when treating humans.

Interactions between voice fundamental frequency and cardiovascular parameters. Preliminary results and physiological mechanisms

OBJECTIVES

To determine heart rate influence on voice fundamental frequency under stress conditions.

METHODS

In 14 healthy volunteers, heart rate and blood pressure variables were analyzed during three classical autonomic tasks. Sustained voice samples were obtained to analyze F0.

RESULTS

Cold pressure test increased mean blood pressure, without effect on heart rate; isometric and mental tasks increased heart rate and blood pressure. Voice F0 was only affected by mental and cold ice tasks; it significantly correlated with the heart rate that occurred before and during every vocal emission.

DISCUSSION

Cardiovascular changes showed that subjects were significantly stressed during autonomic tasks. Heartbeat variations had a regular and significant influence on phonatory frequency, and this effect occurred during baseline and stress conditions.

Lesões organofuncionais do tipo nódulos, pólipos e edema de Reinke

TEMA: lesões organofuncionais são formações benignas decorrentes de comportamento vocal alterado e inadequado, sendo as mais comuns: nódulos, pólipos vocais e edema de Reinke. OBJETIVO: realizar um estudo comparativo dos dados descritos na literatura sobre prega vocal normal e afecções organofuncionais do tipo nódulos, pólipos e edema de Reinke. O estudo foi realizado por meio de um levantamento bibliográfico em periódicos indexados no Science Direct, periódicos Capes, LILACS, SciELO, MedLine e Scopus e livros, no período de 1999 a 2010. CONCLUSÃO: a distribuição dos constituintes da matriz extracelular da lâmina própria lw32da mucosa, fibras elásticas, colágenas, ácido hialurônico e fibronectina, encontra-se alterada nas três afecções. Ocorre modificação das características vibratórias de amplitude, propagação da onda de mucosa e simetria do padrão vibratório devido à presença do aumento de massa nas pregas vocais, ao contrário do que se observa nas pregas vocais sem afecção. O sinal perceptivo-auditivo da qualidade vocal encontrado nas três lesões é a rouquidão, seguida da soprosidade e da aspereza (exceção do edema de Reinke), sinalizando a presença de ruído acústico à emissão, estando presente também, no edema de Reinke, o agravamento considerável da frequência fundamental. Quanto à etiologia observou-se a predominância dos usos incorretos, e quanto à incidência, nódulos e edema de Reinke predominam no sexo feminino e pólipos no sexo masculino.

Tempos máximos de fonação de vogais em mulheres adultas com nódulos vocais

TEMA: tempos máximos de fonação (TMF) de vogais em mulheres adultas com presença de nódulos vocais. OBJETIVO: verificar e correlacionar os valores de TMF de vogais em mulheres adultas jovens e de meia-idade com presença de nódulos vocais. MÉTODO: utilizaram-se os registros do Banco de dados de uma clínica-escola de Fonoaudiologia, totalizando um grupo de 38 sujeitos. Critérios de inclusão: adultos do sexo feminino com idades entre 20 e 53 anos e diagnóstico otorrinolaringológico de nódulos vocais. Critérios de exclusão: apresentar outra patologia laríngea além dos nódulos vocais; comprometimento auditivo; respiração oral; histórico de doenças neurológicas, psiquiátricas, endocrinológicas ou gástricas; gripe ou quadros de alergias; hábitos de etilismo e/ou tabagismo; tratamento fonoaudiológico e/ou otorrinolaringológico prévios. Foram coletados os dados de anamnese, o diagnóstico otorrinolaringológico, e as medidas de TMF das vogais /a, i, u/ de cada sujeito da amostra. A avaliação dos TMF se deu pela medida da duração de três emissões de cada vogal em estudo, em tom e intensidade habituais, até o final da expiração, com o paciente em pé, considerando-se o maior valor de cada vogal. Os resultados foram analisados estatisticamente ao nível de significância de 5%. RESULTADOS: faixa de idade representativa; TMF e média menos representativos, abaixo da normalidade e com forte correlação positiva e significativa entre si; correlação moderada, positiva e significativa entre os TMF entre si e sua média. CONCLUSÃO: na presença de nódulos vocais em um grupo de mulheres adultas, os TMF encontraram-se reduzidos e positivamente correlacionados, o TMF da vogal /a/ apresentou menor valor quando comparado às demais vogais.

Vocal fold nodules: morphological and immunohistochemical investigations

The objective of this study was to investigate the morphological and immunohistochemical characteristics of vocal fold nodules. The study design was prospective and retrospective. For the histological study, we reviewed 15 slides from the surgical cases of vocal fold nodules, in which we analyzed epithelium, basal membrane (bm), and lamina propria. For the transmission and scanning electron microscopy (TEM, SEM) studies, five new cases on vocal fold nodules were included. Immunohistochemistry study was carried out in the 15 specimens, using antifibronectin, antilaminin, and anticollagen IV antibodies. The main histological alterations were epithelial hyperplasia (73.33%), basement membrane thickening (86.66%), edema, and fibrosis (93.33%). SEM--reduction in mucous lacing and increase in the desquamating cells, without epithelial erosion. TEM--hyperplasia of the epithelium, enlargement of the intercellular junctions, which was filled by fluid, subepithelial thickening of the lamina reticularis, and break points in the basal membrane. Immunohistochemistry--we identified greater immunoexpression of fibronectin on the basal membrane, on the lamina propria, and around the vessels. Antilaminin and anticollagen IV antibodies showed higher pigmentation on the endothelium of the vessels than that on the basal membrane. In vocal fold nodules, combined assessment using light microscopy, electron microscopy, and immunohistochemistry can reveal important morphological details useful in characterizing these lesions.

Liquid accumulation in vibrating vocal fold tissue: a simplified model based on a fluid-saturated porous solid theory

The human vocal fold is treated as a continuous, transversally isotropic, porous solid saturated with liquid. A set of mathematical equations, based on the theory of fluid-saturated porous solids, is developed to formulate the vibration of the vocal fold tissue. As the fluid-saturated porous tissue model degenerates to the continuous elastic tissue model when the relative movement of liquid in the porous tissue is ignored, it can be considered a more general description of vocal fold tissue than the continuous, elastic model. Using the fluid-saturated porous tissue model, the vibration of a bunch of one-dimensional fibers in the vocal fold is analytically solved based on the small-amplitude assumption. It is found that the vibration of the tissue will lead to the accumulation of excess liquid in the midmembranous vocal fold. The degree of liquid accumulation is positively proportional to the vibratory amplitude and frequency. The correspondence between the liquid distribution predicted by the porous tissue theory and the location of vocal nodules observed in clinical practice, provides theoretical evidence for the liquid accumulation hypothesis of vocal nodule formation (Jiang, Ph.D., dissertation, 1991, University of Iowa).

A fluid-saturated poroelastic model of the vocal folds with hydrated tissue

The purpose of this study is to develop a continuous model to describe the vibration of the vocal fold with hydrated tissue. This model is unique because it is based on the fluid-saturated porous solid theory. Therefore, this new model can be used to study some vocal fold characteristics that would be difficult to predict using previous models. Numerical simulations show that this model can generate self-oscillation and that its phonation threshold pressure (PTP) is 0.555 kPa. The basic outputs of this model, including fundamental frequency, maximum lateral displacement, surface dynamics, and empirical eigenfunctions, agree with previous models and experimental studies, which validates this new model. The ability to simulate the flow of liquid through the tissue is one of the important advantages of this new model. It was found that the liquid in the vocal fold tissue could be accumulated at the anterior-posterior midpoint during phonation, which could cause a pressure increase in the liquid. The liquid pressure increased from 0.033 to 0.150 kPa when the subglottal pressure increased from 0.555 kPa (PTP) to 0.7 kPa. It was believed that the liquid dynamics in the tissue during phonation could be related to the development of some vocal diseases, such as vocal nodules, edema, and so on. Therefore, we expect that this model might not only provide a more appropriate description of the vocal fold vibration, but that it could also have clinical value in investigating certain vocal fold diseases.

Lesões de borda de pregas vocais e tempos máximos de fonação

OBJETIVO: comparar o diagnóstico otorrinolaringológico de lesão de borda de prega vocal e seus Tempos Máximos de Fonação em adultos e crianças de ambos os sexos; verificar a frequência dos tipos de TMF (reduzido, normal ou aumentado) nas patologias de borda de pregas vocais e a frequência dessas patologias em indivíduos com pregas vocais maduras (adultos) e imaturas (crianças), em ambos os sexos. MÉTODOS: resgate no banco de dados de pacientes com queixas de voz, atendidos em um serviço de atendimento fonoaudiológico universitário, com diagnóstico médico de patologia de borda de prega vocal. Entre os 152 registros apresentados pelo banco de dados, 54 passaram pelos critérios de inclusão, sendo oito casos de cisto vocal e 46 de nódulo vocal. RESULTADOS: os nódulos vocais foram as lesões mais frequentes em adultos e crianças, com maior parcela em mulheres adultas e crianças do sexo masculino. Os cistos vocais ocorreram em maior parcela no sexo feminino tanto em crianças como em adultos. Houve redução nos tempos máximos de fonação de crianças de ambos os sexos e de mulheres adultas. CONCLUSÃO: as lesões de borda de pregas vocais, por dificultarem o adequado fechamento glótico, tendem a causar redução nos valores de Tempos Máximos de Fonação.