Vocal exercise may attenuate acute vocal fold inflammation

Mechanotransduction in the Vocal Fold Microenvironment: A Narrative Review

PURPOSE

The vocal fold tissues undergo nearly continuous and repeated cycles of injury and repair throughout the course of an individual's lifetime. It is well established that certain individuals are at greater risk of lesion development based on personality and behavioral classification. However, these characteristics alone do not wholly predict or explain lesion development or severity. In this review, we discuss current knowledge of mechanotransduction proteins and their potential relevance to tissue homeostasis in the vocal folds.

METHOD

A review of literature surrounding mechanotransduction and tissue homeostasis as it relates to the vocal folds was conducted. Review of the literature included searches of PubMed, Google Scholar, and other various online peer-reviewed sources. Search terms pertained to mechanosensation, mechanotransduction, mechanically activated channels, mechanical cellular regulation, and other associated concepts and terms. Additional literature was identified through the reference lists of identified papers. Findings of this literature review were then applied to known physiology and pathophysiology of the vocal folds in order to speculate on the contribution of mechanically mediated mechanisms within the vocal fold.

DISCUSSION AND CONCLUSION

Because the vocal folds are such mechanically active structures, withstanding nearly constant external forces, there is strong support for the idea that mechanically sensitive molecular pathways within the vocal fold tissue play a major role in tissue homeostasis in the presence of these considerable forces. As such, mechanotransduction within the vocal fold should be considered and targeted in future biological studies of vocal fold physiology.

Early Initiation of Voice Therapy After Microlaryngeal Surgery - A Randomized Control Study

OBJECTIVE

A prospective single blinded randomized control trial was conducted to study if early initiation of voice therapy after microlaryngeal produces a better voice outcome in patients with benign vocal fold lesions.

METHODS

In this Patients undergoing microlaryngeal surgery for benign vocal fold lesions were recruited for the study and underwent voice evaluation and videostroboscopy preoperatively. Participants were randomised into two groups depending on the duration of voice rest-A (2 days voice rest) and B (5 days voice rest). Following the period of voice rest, voice therapy (tube phonation) was carried out for a month. Postoperative evaluation was done at 6 weeks (over telephone) and 3 months (in person visit) follow up. Outcome measures included the VHI-10, auditory-perceptual voice ratings, acoustic analysis and videostroboscopic vibratory ratings.

RESULTS

Of the 50 subjects, 35 completed the follow up evaluation. The overall compliance to absolute voice rest was 43%. Among the various parameters used for voice evaluation, there was no statistically significant difference between the two groups except for jitter, where the improvement in 5 day voice rest group compared to the 2 day voice rest group was statistically significant.

CONCLUSION

Prolonged voice rest after microlaryngeal surgery is difficult to comply with. As there was no significant difference between the two study groups, clinicians may prescribe a shorter duration of voice rest followed by early initiation of voice therapy after microlaryngeal surgery.

Hypertonic Aerosols Hydrate Airways Longer and Reduce Acidification Risk with Nonpermeating Cation and Permeating Anion Salts

Background: Hyperosmolar aerosols appear to promote or suppress upper airway dysfunction caused by dehydration in a composition-dependent manner. We sought to explore this composition dependence experimentally, in an interventional human clinical study, and theoretically, by numerical analysis of upper airway ion and water transport. Methods: In a double-blinded, placebo-controlled clinical study, phonation threshold pressure (PTP) was measured prenasal and postnasal inhalation of hypertonic aerosols of NaCl, KCl, CaCl2, and MgCl2 in seven human subjects. Numerical analysis of water and solute exchanges in the upper airways following deposition of these same aerosols was performed using a mathematical model previously described in the literature. Results: PTP decreased by 9%-22% relative to baseline (p < 0.05) for all salts within the first 30 minutes postadministration, indicating effective laryngeal hydration. Only MgCl2 reduced PTP beyond 90 minutes (21% below baseline at 2 hours postadministration). By numerical analysis, we determined that, while airway water volume up to 15 minutes postdeposition is dictated by osmolarity, after 30 minutes, divalent cation salts, such as MgCl2, better retain airway surface liquid (ASL) volume by slow paracellular clearance of the divalent cation. Fall of CFTR chloride flux with rise in ASL height, a promoter of airway acidification, appears to be a signature of permeating cation (NaCl) and nonpermeating anion (mannitol) aerosol deposition. For hypertonic aerosols that lack permeating cation and include permeating anion (CaCl2 and MgCl2), this acid-trigger signature does not exist. Conclusions: Nonpermeating cation and permeating anion hypertonic aerosols appear to hydrate upper airways longer and, rather than provoke, may reduce laryngeal dysfunction such as cough and bronchoconstriction.

Acoustic Effects of Vocal Warm-Up: A 7-Week Longitudinal Case Study

OBJECTIVE

A case study was used to determine which acoustic parameters would be sensitive to a SOVT-based vocal warm-up over the duration of a standard voice treatment.

METHODS

The longitudinal research design consisted of repeated voice measures during 7 weeks from a single subject, a 48-year-old male occupational voice user with a history of voice disorders. A steady phonation and running speech tasks were performed before and after an intensive 1-minute water-resistance voice exercise (WRT). Acoustic assessment of the pre-and postrecordings from each session was obtained with freely accessible software (e.g., Audacity, PRAAT) and acoustic measures (e.g., fundamental frequency, jitter, shimmer, alpha ratio, NHR, HNR, L1L0, Cepstral Peak Prominence smoothed).

RESULTS

After WRT, the analysis indicated that jitter, shimmer, and NHR had a small but statistically significant decrease, while alpha ratio, CPPS, and HNR had a statistically significant increase. For the days where there were six repetitions, there was a larger effect in the later repetitions in the day for some metrics (i.e., alpha ratio, shimmer, NHR, CPPS), while others had the biggest effect in the first two repetitions in a day (i.e., jitter, HNR).

CONCLUSIONS

A short vocal water-resistance voice task had a positive effect on the short-term acoustic voice metrics after each repetition of the exercise, independent of the number of repetitions throughout the day. When five repetitions of this exercise routine occurred, there was a more substantial influence on the proportion of acoustic voice changes.

An eclectic Voice Therapy Program for the Treatment of Hyperfunctional Voice Disorders (HFVD)

PURPOSE

An eclectic voice therapy program includes sequenced and structured set of exercises combining direct and indirect intervention methods. Tailor-made exercise prescription with specific cultural adaptations are needed to provide a holistic change to voice quality.1 This study detailed the construction of an exercise prescription for participants with hyperfunctional voice disorder [HFVD] in the Indian context.

METHOD

The exercise program was developed based on literature related to vocal therapy approaches and delivery methods. Adaptations were introduced to a selected set of exercises. Five voice experts verified the exercises and their prescription for content and feasibility of use in the Indian context. Modification suggested by the experts were included for framing the final version of the exercise program. This structured therapy program was planned for 6 weeks (30 minutes duration/session offered individually twice per week, with a gap of two days between sessions in a week) with the goals to improve voice quality, flexibility, and endurance while speaking. Five participants with HFVD partook in the study for pilot testing. Stroboscopy, perceptual voice analysis, Dysphonia Severity Index (DSI) and Vocal Fatigue Index in Tamil (VFI-T) were used to report the therapy outcomes. Participants' report on the learning process and generalization of the program were documented. Wilcoxon-signed rank test was used to test the pre-post outcome measures.

RESULTS

An eclectic voice therapy program, i.e., Comprehensive Voice Habilitation Program [CVHP] was constructed and it included vocal hygiene instructions, warm-up & cool-down, easy onset, resonant voice, and carry over exercises. Participants completed the program in 14-18 sessions (over 7 to 9 weeks of therapy). All participants showed significant changes in vocal fold movement patterns, reduction in ventricular hyperadduction, overall grade of voice quality, DSI and VFI-T. Participants reported that pictorial illustrations, feedback, and monitoring sheets were useful in learning the exercises.

CONCLUSION

CVHP showed significant change in the voice-related outcome measures and was a viable program for treating HFVD.

The influence of source-filter interaction on the voice source in a three-dimensional computational model of voice production

The goal of this computational study is to quantify global effects of vocal tract constriction at various locations (false vocal folds, aryepiglottic folds, pharynx, oral cavity, and lips) on the voice source across a large range of vocal fold conditions. The results showed that while inclusion of a uniform vocal tract had notable effects on the voice source, further constricting the vocal tract only had small effects except for conditions of extreme constriction, at which constrictions at any location along the vocal tract decreased the mean and peak-to-peak amplitude of the glottal flow waveform. Although narrowing in the epilarynx increased the normalized maximum flow declination rate, vocal tract constriction in general slightly reduced the source strength and high-frequency harmonic production at the glottis, except for a limited set of vocal fold conditions (e.g., soft, long vocal folds subject to relatively high pressure). This suggests that simultaneous laryngeal and vocal tract adjustments are required to maximize source-filter interaction. While vocal tract adjustments are often assumed to improve voice production, our results indicate that such improvements are mainly due to changes in vocal tract acoustic response rather than improved voice production at the glottis.

A Review of Factors Associated with Voice Problems in the Fitness Instructor Population

There is a high prevalence of reported dysphonia symptomology in the fitness instructor population. This is concerning as these reported symptoms of dysphonia, aphonia, and vocal fatigue can significantly compromise quality of life. The purpose of this review is to explore key factors that may contribute to voice problems in the fitness instructor population. Voicing with concurrent phonation and exercise may be influenced by (1) the increased cardiovascular requirement during exercise, (2) the increased cognitive load associated with dual tasking, (3) the altered hydration state associated with prolonged exercise, and (4) the phonatory dose associated with continued voicing with loud background music. This manuscript will explore the literature on these key factors (ie, phonatory dose, dehydration, metabolic bioenergetics, cognitive load, and psychosocial stress) as they pertain to fitness instructors.

Amateur choir singers - Does good vocal health matter?

BACKGROUND

Many amateur singers enjoy singing in choirs. They are likely to lack the training and expertise of professional singers and this may have an impact on their vocal health.

AIMS

To assess the experiences of amateur singers, their use of warm-up and cool-down sessions, their vocal health, their sources of help and advice and their reactions to receiving a diagnosis and treatment.

METHODS AND PROCEDURES

A questionnaire was sent to amateur choir singers. Quantitative data on their use of warm-up and cool-down activities were collected and the singers rated how frequently they experienced adverse voice symptoms after singing. Qualitative data were collected from singers who had sought advice about their voice and from those who had received a diagnosis and treatment.

OUTCOME AND RESULTS

Most choirs used warm-up sessions but few used cool-down. Singers who participated in choir warm-ups experienced significantly less vocal symptoms. Individual warm-ups were ineffective. Singers who had previously had a diagnosis continued to have significantly higher symptom scores. A quarter of the singers who had neither sought help nor had a diagnosis had high scores. Singers appeared uncertain about who to consult for help. Those who saw a speech and language therapist were much more likely to receive a diagnosis and treatment either by the therapist or by referral to an ear, nose and throat specialist. Those receiving treatment were mainly positive about it and likely to complete a course of therapy.

CONCLUSIONS AND IMPLICATIONS

Warm-up sessions performed by choirs are helpful in avoiding voice symptoms and are recommended. The presence of singers who are unaware of potential damage to their voices is a concern. A simple rating system, as used in this research, may act to alert them to the dangers. Choir leaders could be more active in advising singers and refer them to professionals where necessary. Speech and language therapists appear more sensitive to their problems and could be a first point of contact.

WHAT THIS PAPER ADDS

What is already known on this subject Poor vocal health may occur in amateur singers and lead to voice disorders which will reduce the demonstrated benefits of regular singing. They may be less aware than professional singers of potential hazards and may not know how to sing in a way that ensures good vocal health. There has been less research on the extent of voice problems in amateurs or of the actions they may take to resolve the vocal difficulties they encounter. What this paper adds to the existing knowledge This survey demonstrates that choir warm-ups were effective in helping to avoid common symptoms associated with voice problems. A large minority of singers who had not sought help for voice problems had high symptom scores on our assessment. Singers frequently turned to a singing teacher for help. Those who consulted a speech and language therapist were much more likely to be referred for further investigation and treatment. What are the potential or actual clinical implications of this work? We present a simple subjective measure of symptom severity which succeeds in distinguishing between singers who warm up their voices and those who do not and between singers who have received a past diagnosis and those who have not. There are a number of indications in this research that amateur singers are unsure if they need help and are uncertain who can offer it. In these circumstances the use of a simple measure of the severity of vocal abuse may be useful.

Variability in Voice Characteristics of Female Speakers With Phonotraumatic Vocal Fold Lesions

OBJECTIVE

To examine the variability of lesion characteristics and vocal function in female speakers with phonotraumatic vocal fold lesions (PVFLs).

STUDY DESIGN

Prospective Cohort Study METHODS: Thirty adult female speakers with PVFL who were participating in voice therapy were recruited to complete a multidimensional voice analysis at four time points across 1 month. Analysis comprised self-ratings of effort and vocal function, expert ratings of videostroboscopy and audio recordings, and instrumental evaluation by selected aerodynamic and acoustic parameters. The degree of variability across time for each individual was assessed against a minimal clinically important difference threshold.

RESULTS

A high degree of variability across time was observed for participant self-ratings of perceived effort and vocal function, and for instrumental parameters. The greatest degree of variability was observed in aerodynamic measures of airflow and pressure, and the acoustic parameter semitone range. Comparatively less variability was observed in perceptual evaluation of speech, and lesion characteristics via stroboscopy still images. Findings suggest that individuals with all PVFL types and sizes present with variability in function across time, with the greatest degree of variability in function observed in participants with large lesions and vocal fold polyps.

CONCLUSION

Variability is observed in voice characteristics of female speakers with PVFLs across 1 month despite general stability in lesion presentation, suggesting vocal function can change despite the presence of laryngeal pathology. This study highlights the need to explore individual functional and lesion responses across time to determine potential for change and improvement in both aspects when selecting treatment options.

Pre- and Postoperative Voice Therapy for Benign Vocal Fold Lesions: An International Electronic Delphi Consensus Study

INTRODUCTION

Voice therapy management of benign vocal fold lesions (BVFLs) is variable and there are currently no clinical guidelines. Poor descriptions of voice therapy interventions lead to unwarranted variation in treatment. Triangulation of the current evidence identifies a number of potential best practice elements, but also a number of outstanding questions to be explored. The aim of this study was to refine and gain global consensus on "best practice" for a pre- and postoperative voice therapy intervention for adults with BVFLs.

METHODS

An international sample of expert voice therapists (n = 42) were recruited to take part in this three-round electronic modified Delphi study. Participants were presented with statements concerning a pre- and postoperative voice therapy intervention. Statements were developed from previous research and based on the TIDieR checklist (eg, why, when, what, how?) Participants rated the extent to which they agreed or disagreed with a statement and gave comments to support their response. Consensus was defined as >75% of participants agreeing or strongly agreeing with a given statement. If consensus was not reached, participant comments were used to generate new statements and were rated in the next round. Stability of consensus between rounds was assessed.

RESULTS

The 42 international experts achieved consensus on 33 statements relating to components of a best practice pre- and postoperative voice therapy intervention for patients with BVFLs. Consensus on statements ranged from 81% to 100%. These statements were explicitly mapped to the TIDieR checklist to ensure that all aspects of the intervention were considered and the questions of "why, what, how, when and individual tailoring" were addressed.

CONCLUSIONS

This study has significantly enhanced our understanding of what should be in a best practice pre- and postoperative voice therapy intervention. It is important to now test these findings for acceptability and feasibility, prior to considering effectiveness research.

Pre- and post-operative voice therapy (PaPOV): Development of an intervention for patients with benign vocal fold lesions

BACKGROUND

Pre- and post-operative voice therapy may improve voice and quality-of-life outcomes for patients undergoing phonosurgery to remove benign vocal fold lesions (BVFLs). However, what constitutes voice therapy in this population is poorly described, resulting in a poor evidence base, lack of clinical guidelines and unwarranted variation in management. In order to develop the evidence base, a robust, iterative process of intervention development work should precede feasibility testing and effectiveness studies.

METHODS & PROCEDURES

Guidance for developing complex interventions, drawing on evidence, theory and modelling, was used to inform the development of a pre- and post-operative voice therapy intervention entitled 'PaPOV'. Data from four sources of evidence were synthesized using a published triangulation protocol. Data from a systematic review, national survey of current practice, expert interview study, and patient and public involvement conversations were used to populate a triangulation matrix, outlining components of a PaPOV. Data were coded to reflect areas of agreement, dissonance and silence with each component of the intervention. Based on this evidence, an assessment of convergence for each intervention component could be made.

OUTCOMES & RESULTS

In total, 61 components of the PaPOV intervention were explored. Of these, 27 were categorized as having stability of consensus according to a priori criteria. A total of 34 failed to meet the criteria. This was more frequently due to silence (27) rather than dissonance (seven) in the data. By evidencing areas of agreement and stability of consensus across data sources, the validity of individual findings has been enhanced. Furthermore, the study has exposed specific areas of the intervention that lack consensus and require exploration through further intervention development studies.

CONCLUSIONS & IMPLICATIONS

This systematic triangulation process has contributed to the development of a PaPOV intervention for patients with BVFLs. Exploration of specific components relating to the intervention will allow outstanding questions to be answered in preparation for feasibility testing.

WHAT THIS PAPER ADDS

What is already known on the subject BVFLs cause dysphonia by preventing vocal fold closure, impacting on vibratory characteristics and increasing compensatory muscle tension. Management for these patients is variable with them being offered phonosurgery, voice therapy, pharmacological management or a combined approach. Pre- and post-operative voice therapy may improve both voice and quality-of-life outcomes. This patient group has unique complexities when considering voice therapy, including surgical preparation, wound healing and epithelial mobilization. What this paper adds to existing knowledge This study uses a robust triangulation process to synthesize current evidence and patient experiences in order to inform the development of a PaPOV. It outlines some of the key components and considerations when delivering pre- and post-operative voice therapy to adults with BVFLs. Furthermore, it serves as a methodological example for intervention development in complex interventions, highlighting key guidance and recommended processes for developing and evaluating complex interventions. What are the potential or actual clinical implications of this work? The 61 components discussed as potential 'ingredients' for a PaPOV enable clinicians to reflect on key considerations when planning and delivering voice therapy to adults with BVFLs. This study highlights the pitfalls both clinically and in research of failing to describe interventions adequately and the benefits of using accurate, specific and agreed terminology in clinical practice, such as that outlined in the Rehabilitation Treatment Specification System (TRSS).

Acoustic Description of Bhramari Pranayama

The study's aim was (1) To describe the acoustic characteristics of Bhramari pranayama, and (2) to compare the acoustic features of nasal consonant /m/ and the sound of Bhramari pranayama produced by yoga trainers. Cross-sectional study design. Thirty-three adult male yoga trainers performed five repeats of nasal consonant /m/ and Bhramari pranayama. These samples were recorded into Computerized Speech Lab, Kay Pentax model 4500b using a microphone (SM48). Formant frequencies (f F1, f F2, f F3, & f F4), formant bandwidths (BF1, BF2, BF3, & BF4), anti-formant, alpha and beta ratio were analyzed. Nasal consonant /m/ had higher f F2 and anti-formant compared to Bhramari pranayama. Statistical significant differences were noted in f F2, BF3, and anti-formants. Bhramari pranayama revealed a low alpha ratio and a higher beta ratio than /m/. However, these differences were not statistically significant. Findings are discussed from acoustic and physiological perspectives. Bhramari pranayama was assumed to be produced with a larger pharyngeal cavity and narrower velar passage when compared to nasal consonant /m/. Verification at the level of the glottis and with aerodynamic parameters may ascertain the above propositions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-021-03054-1.

Office-Based Structural Autologous Fat Injection Laryngoplasty for Unilateral Vocal Fold Paralysis

Unilateral vocal fold paralysis (UVFP) is a common cause of incomplete glottic closure, leading to significant somatic and social disabilities. Office-based autologous fat injection laryngoplasty (AFIL) has been proposed as an effective treatment for glottic insufficiency but has not been well-studied for UVFP. We enrolled 23 patients who underwent office-based structural AFIL due to unilateral vocal paralysis at our institution between February 2021 and January 2022. In the procedure, autologous fat was harvested and injected into the vocal fold under the guidance of flexible digital endoscopy for structural fat grafting. The voice handicap index-10 (VHI-10) score and perceptual voice measurements were collected before the operation, 2 weeks postoperatively, and 3 months postoperatively. Twenty-two patients were followed-up for at least 3 months. The VHI-10 score improved significantly from 29.65 ± 8.52 preoperatively to 11.74 ± 7.42 at 2 weeks (p < 0.0001) and 5.36 ± 6.67 at 3 months (p < 0.0001). Significant improvements in grades of dysphonia (p < 0.0001), breathiness (p < 0.0001), and asthenia (p = 0.004) were also noted at 3 months postoperatively when perceptual measurements were investigated. Office-based structural AFIL is an effective treatment for improving voice-related disability for UVFP patients.

Diagnostic Accuracy of Liquid Biomarkers in Airway Diseases: Toward Point-of-Care Applications

Background

Liquid biomarkers have shown increasing utility in the clinical management of airway diseases. Salivary and blood samples are particularly amenable to point-of-care (POC) testing due to simple specimen collection and processing. However, very few POC tests have successfully progressed to clinical application due to the uncertainty and unpredictability surrounding their diagnostic accuracy.

Objective

To review liquid biomarkers of airway diseases with well-established diagnostic accuracies and discuss their prospects for future POC applications.

Methodology

A literature review of publications indexed in Medline or Embase was performed to evaluate the diagnostic accuracy of liquid biomarkers for chronic obstructive pulmonary disease (COPD), asthma, laryngopharyngeal reflux (LPR), and COVID-19.

Results

Of 3,628 studies, 71 fulfilled the inclusion criteria. Sputum and blood eosinophils were the most frequently investigated biomarkers for the management of asthma and COPD. Salivary pepsin was the only biomarker with a well-documented accuracy for the diagnosis of LPR. Inflammatory blood biomarkers (e.g., CRP, D-dimers, ferritin) were found to be useful to predict the severity, complications, and mortality related to COVID-19 infection.

Conclusion

Multiple liquid biomarkers have well-established diagnostic accuracies and are thus amenable to POC testing in clinical settings.

The Efficacy of Functional Endoscopic Sinus Surgery Combined With Triamcinolone Acetonide Aqueous Nasal Spray for the Treatment of Chronic Rhinosinusitis

Objective

We aimed to investigate the efficacy of functional endoscopic sinus surgery (FESS) combined with triamcinolone acetonide aqueous nasal spray (TAA AQ) for the treatment of chronic rhinosinusitis.

Methods

From December 2019 to June 2021, 109 patients with chronic rhinosinusitis were classified into a control group (n = 50) and an experimental group (n = 59) according to the method of treatment. Subjects in the control group were treated with FESS while those in the experimental group were treated with FESS + TAA AQ. We then compared clinical indices, total effective rate, and the clinical symptoms of patients between the two groups. The pre- and postoperative serum levels of inflammatory cytokines were also determined. Before and 12 months after surgery, we analyzed the recovery of the nasal mucosa, olfactory function, and mucociliary transport rate of each patient. Postoperative complications were observed and recorded and the quality-of-life 12 months after surgery was ascertained.

Results

Clinical indices and total effective rate were higher in the experimental group. After treatment, the VAS score and serum levels of inflammatory cytokines in the two groups both decreased, although the experimental group had lower VAS scores and inflammatory cytokine levels. Six months after treatment, olfactory function, and the recovery of nasal mucosa were improved, MTR had increased, and the total incidence of complications had reduced in the experimental group when compared with the control group. No significant difference was found between the two groups in terms of quality-of-life (P > 0.05).

Conclusion

The combination of FESS and TAA AQ exerted a certain therapeutic effect on chronic rhinosinusitis.

The effects of vocal exertion on lung volume measurements and acoustics in speakers reporting high and low vocal fatigue

Purpose

Vocal exertion is common and often results in reduced respiratory and laryngeal efficiency. It is unknown, however, whether the respiratory kinematic and acoustic adjustments employed during vocal exertion differ between speakers reporting vocal fatigue and those who do not. This study compared respiratory kinematics and acoustic measures in individuals reporting low and high levels of vocal fatigue during a vocal exertion task.

Methods

Individuals reporting low (N = 20) and high (N = 10) vocal fatigue participated in a repeated measures design study over 2 days. On each day, participants completed a 10-minute vocal exertion task consisting of repeated, loud vowel productions at elevated F0 sustained for maximum phonation time. Respiratory kinematic and acoustic measures were analyzed on the 1^st vowel production (T0), and the vowels produced 2 minutes (T2), 5 minutes (T5), 7 minutes (T7), and 10 minutes (T10) into the vocal exertion task. Vowel durations were also measured at each time point.

Results

No differences in respiratory kinematics were observed between low and high vocal fatigue groups at T0. As the vocal exertion task progressed (T2-T10), individuals reporting high vocal fatigue initiated phonation at lower lung volumes while individuals with low vocal fatigue initiated phonation at higher lung volumes. As the exertion task progressed, total lung volume excursion decreased in both groups. Differences in acoustic measures were observed, as individuals reporting high vocal fatigue produced softer, shorter vowels from T0 through T10.

Conclusions

Individuals reporting high vocal fatigue employed less efficient respiratory strategies during periods of increased vocal demand when compared with individuals reporting low vocal fatigue. Individuals reporting high vocal fatigue had shorter maximum phonation time on loud vowels. Further study should examine the potential screening value of loud maximum phonation time, as well as the clinical implications of the observed respiratory patterns for managing vocal fatigue.

H2O2 Concentration in Exhaled Breath Condensate Increases After Phonotrauma: A Promise of Noninvasive Monitoring?

PURPOSE

The present study was designed to observe the concentration of hydrogen peroxide (H2O2) in exhaled breath condensate (EBC) after induced phonotrauma.

METHODS

Thirty-five participants were randomly assigned to one of two conditions (1) Vocal demand and (2) Control. Participants in the experimental group (vocal demand) were asked to read aloud some texts during 1 hour, at 85-90 dB. Inflammation (H2O2 from exhaled breath condensate), acoustic, aerodynamic, and subjective measures were obtained at four time points: before vocal demand (baseline), immediately after baseline, 4-hour after baseline, and 24 hours after baseline. The same acquisition process was implemented for subjects in control group, except that they were not asked to engage in any vocal demand tasks at all.

RESULTS

As for biological samples, a significant effect for group was observed. Higher values were found for participants in experimental condition. Significant differences were observed for within contrasts in the experimental group, namely 4 hours against baseline, 4 hours against immediately post, and 24 hours against 4 hours. Instrumental outcomes did not show significant differences across the different conditions at any time points. Self-reported measures (vocal fatigue and sensation of muscle tension) showed a significant main effect for group and main effect for condition.

CONCLUSIONS

Intense vocal demand causes an increase in the concentration of H2O2 obtained from EBC at four hours after baseline, which is compatible with the generation of an inflammatory process in the vocal folds (phonotrauma). Moreover, the increase in the sensation of vocal fatigue and muscle tension after demand tasks seems to be an immediate reaction that did not match in time with the increment of H2O2 concentration.

The Immediate Impact of Targeted Exercises on Voice Characteristics in Female Speakers With Phonotraumatic Vocal Fold Lesions

OBJECTIVE

To examine the immediate impact of 30 minutes of targeted voice exercises on measures of vocal function and lesion characteristics in female speakers with phonotraumatic vocal fold lesions (PVFLs).

STUDY DESIGN

Prospective cohort study.

METHOD

Twenty-nine (n = 29) female subjects with PVFLs completed a 30 minutes targeted voice exercise protocol and a multidimensional voice analysis was conducted immediately pre and post-exercise. Analysis included expert perceptual evaluation of connected speech and stroboscopy recordings, instrumental analysis by selected aerodynamic and acoustic parameters, and self-ratings of effort and vocal function by participants. The direction and magnitude of the change from pre- to post-exercise for each individual across parameters was assessed against a Minimal Clinically Important Difference criteria.

RESULTS

Variability was observed among participants in their response to exercise and across parameters. Multidirectional change in function was demonstrated across instrumental parameters, with observations of both improvement and decline. The most consistent change observed was a reduced PTP post-exercises for 38% of participants (n = 11), and the greatest magnitude of change was observed in aerodynamic measures of airflow and pressure, and the acoustic parameter semitone range. Variability in the direction of change across instrumental measures was observed for 24% of participants (n = 7), while consistent improved function was seen for 45% (n = 13), declined function for 17% (n = 5) and no change for 14% (n = 4). Participant's self-reported effort and function post-exercise was also multidirectional, with the greatest number reporting improvement. Comparatively little change was observed in perceptual evaluation of speech and stroboscopy recordings. Findings suggest that individuals with all lesion types, sizes and liabilities have the potential to improve vocal function immediately post-exercises according to instrumental measures, with the greatest magnitude of change observed in participants with large lesions. Although participants' characteristics did not differentiate, those with nodules or polyps tended to report improvement in function and reduced effort post-exercise, whereas those with a diagnosis of pseudocyst/s or a unilateral lesion appeared to report no change or declined function.

CONCLUSION

Change in measures of vocal function was observed in female speakers with PVFLs immediately following a 30 minutes targeted exercises protocol. Many demonstrated improvement but a high degree of variability was observed in the way speakers respond, and it is likely an individual's response is influenced by a range of factors. Self-rating scales, along with key instrumental parameters sensitive to the presence of PVFLs, may prove most useful in tracking initial change in the immediate and short-term duration in this population, and in assessing stimulability and candidacy for therapy. Further exploration is warranted of stimulability for immediate and cumulative change to achieve sustained improvement in function and efficiency across time.

Bioreactors for Vocal Fold Tissue Engineering

It is estimated that almost one-third of the United States population will be affected by a vocal fold (VF) disorder during their lifespan. Promising therapies to treat VF injury and scarring are mostly centered on VF tissue engineering strategies such as the injection of engineered biomaterials and cell therapy. VF tissue engineering, however, is a challenging field as the biomechanical properties, structure, and composition of the VF tissue change upon exposure to mechanical stimulation. As a result, the development of long-term VF treatment strategies relies on the characterization of engineered tissues under a controlled mechanical environment. In this review, we highlight the importance of bioreactors as a powerful tool for VF tissue engineering with a focus on the current state of the art of bioreactors designed to mimic phonation in vitro. We discuss the influence of the phonatory environment on the development, function, injury, and healing of the VF tissue and its importance for the development of efficient therapeutic strategies. A concise and comprehensive overview of bioreactor designs, principles, operating parameters, and scalability are presented. An in-depth analysis of VF bioreactor data to date reveals that mechanical stimulation significantly influences cell viability and the expression of proinflammatory and profibrotic genes in vitro. Although the precision and accuracy of bioreactors contribute to generating reliable results, diverse gene expression profiles across the literature suggest that future efforts should focus on the standardization of bioreactor parameters to enable direct comparisons between studies. Impact statement We present a comprehensive review of bioreactors for vocal fold (VF) tissue engineering with a focus on the influence of the phonatory environment on the development, function, injury, and healing of the VFs and the importance of mimicking phonation on engineered VF tissues in vitro. Furthermore, we put forward a strong argument for the continued development of bioreactors in this area with an emphasis on the standardization of bioreactor designs, principles, operating parameters, and oscillatory regimes to enable comparisons between studies.

The Impact of Fish Oil Supplementation on Self-Perception of the Voice in Vocal Performers: A Randomized, Single-Blind, Placebo-Controlled Study

PURPOSE

Physically active adults have experienced training benefits from fish oil-derived omega-3 fatty acid (FO n3), which may also be of benefit to singers. The purpose of this research study was to determine if self-reported vocal adaptations and body composition changes occur in singers following FO n3 supplementation in conjunction with a singer's normal training regimen.

METHOD

Twenty college students, currently enrolled in vocal lessons at a university, were randomized to receive either 3.0 g of FO n3 or placebo, which they took during a 10-week study period. Participants were blinded to group assignment. Participants completed the Reflux Symptom Index (RSI), Singing Voice Handicap Index-10 (SVHI-10), and the Evaluation of Ability to Sing Easily (EASE) and submitted to body composition measures (weight, skeletal mass, and body fat mass) before and after the study period.

RESULTS

Sixteen participants completed all parts of the study protocol. Mean compliance for the placebo group (83.9%) and the supplement group (75.2%) was similar. There were no significant differences in body composition measures, RSI scores, and EASE scores between groups. Scores on the SVHI-10 decreased significantly over time for all participants.

CONCLUSIONS

Improvements seen in the SVHI-10 were not meaningfully different between the supplement and placebo group, pointing to the benefit of weekly lessons. The lack of changes in the questionnaire scores in the supplement group are partially attributed to the low compliance rate and low sample size, which is supported by the lack of change in the body composition measures.

Distribution and Appearance of Ki-67, IL-1α, IL-10, and PGP 9.5 in Reinke's Oedema-Affected Larynx Tissue Compared with Control Tissue

Smoking, laryngopharyngeal reflux, and vocal fold abuse can promote the development of Reinke’s oedema, leading to vocal fold dysfunction and injury. The aim of the work was to investigate the appearance and distribution of proliferation marker Ki-67 (Ki-67), interleukin 10 (IL-10), interleukin 1 alpha (IL-1α), and protein gene peptide 9.5 (PGP 9.5) in Reinke’s oedema-affected larynx tissue. Methods: A routine histological and immunohistochemical Reinke’s oedema and control group patient analysis was conducted. We used the biotin–streptavidin biochemical method to detect Ki-67, IL-10, IL-1α, and PGP 9.5 The semiquantitative grading method was used to evaluate immunoreactive cells’ appearance and local distribution. A Mann–Whitney U test and Spearman’s rank coefficient were performed. Results: A low positive correlation between IL-1α epithelial and subepithelial immunoreactive cells in the patient group was found. Mann–Whitney U tests revealed significant patient and control group immunoreactive marker differences. All examined markers showed a higher number of immunoreactive structures in the patient group. Conclusions: Intensive proliferation of the surface epithelium was observed in patient tissues. The notable increase in IL-10 positive structures indicates the dominant anti-inflammatory tissue response. An increased number of IL-1α structures in the larynx epithelium and subepithelium in the patient group is linked to inflammation, proliferation, and tissue remodelling. The PGP 9.5 expression increase is involved in the morphopathogenesis of Reinke’s oedema.

Mitigating the Effects of Acute Vocal Exertion in Individuals With Vocal Fatigue

OBJECTIVES/HYPOTHESIS

To investigate the effects of acute vocal exertion on individuals with vocal fatigue and to determine whether semi-occluded vocal tract exercises (SOVTEs) are more effective than vocal rest in mitigating acute effects.

STUDY DESIGN

Prospective, repeated-measures design.

METHODS

On consecutive days, 10 individuals (6 males, 4 females) with scores indicating vocal fatigue on the Vocal Fatigue Index completed two 10-minute vocal exertion tasks. Vocal rest or SOVTEs were interspersed in counterbalanced order between exertion tasks. Respiratory kinematic, acoustic, aerodynamic, and self-perceptual measures were collected at baseline, following vocal exertion, following SOVTE/vocal rest, and following the second exertion task.

RESULTS

Acute vocal exertion worsened phonation threshold pressure (P < .001) and vocal effort (P < .001) and reduced maximum fundamental frequency (P < .001). Speech was terminated at lower lung volumes following vocal exertion (decreased lung volume termination [LVT], P < .001). Exertion-induced changes in vocal effort and LVT were significantly reversed by both vocal rest and SOVTE. Detrimental changes in voice measures reoccurred following the second vocal exertion task. SOVTE and vocal rest protected against changes in respiratory kinematics when vocal exertion was resumed.

CONCLUSIONS

Vocal exertion impacted laryngeal, respiratory, and self-perceptual measures in individuals with vocal fatigue. Both SOVTE and vocal rest partially mitigated changes in voice measures and prompted more efficient respiratory strategies that were maintained when vocal exertion resumed. These data increase our understanding of how individuals with vocal fatigue respond to vocal exertion tasks and offer preliminary guidance for optimal clinical recommendations.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:2732-2739, 2021.

Terapia de voz en el contexto de la pandemia covid-19; recomendaciones para la práctica clínica

INTRODUCTION

Since the beginning of the new pandemic, COVID-19 health services have had to face a new scenario. Voice therapy faces a double challenge, interventions using telepractice, and delivering rehabilitation services to a growing population of patients at risk of functional impairment related to the COVID-19 disease. Moreover, as COVID-19 is transmitted through droplets, it is critical to understand how to mitigate these risks during assessment and treatment.

OBJECTIVE

To promote safety, and effective clinical practice to voice assessment and rehabilitation in the pandemic COVID-19 context for speech-language pathologists.

METHODS

A group of 11 experts in voice and swallowing disorders from 5 different countries conducted a consensus recommendation following the American Academy of Otolaryngology-Head and Neck Surgery rules building a clinical guide for speech-language pathologists during this pandemic context.

RESULTS

The clinical guide provides 79 recommendations for clinicians in the management of voice disorders during the pandemic and includes advice from assessment, direct treatment, telepractice, and teamwork. The consensus was reached 95% for all topics.

CONCLUSION

This guideline should be taken only as recommendations; each clinician must attempt to mitigate the risk of infection and achieve the best therapeutic results taking into account the patient's particular reality.

Terapia Vocal No Contexto Da Pandemia Do Covid-19; Orientações Para A Prática Clínica

INTRODUCTION

Since the beginning of the new pandemic, Corona Virus Disease 2019 (COVID-19) health services have had to face a new scenario. Voice therapy faces a double challenge, interventions using telepractice, and delivering rehabilitation services to a growing population of patients at risk of functional impairment related to the COVID-19 disease. Moreover, as COVID-19 is transmitted through droplets, it is critical to understand how to mitigate these risks during assessment and treatment.

OBJECTIVE

To promote safety, and effective clinical practice to voice assessment and rehabilitation in the pandemic COVID-19 context for speech-language pathologists.

METHODS

A group of 11 experts in voice and swallowing disorders from five different countries conducted a consensus recommendation following the American Academy of Otolaryngology-Head and Neck Surgery rules building a clinical guide for speech-language pathologists during this pandemic context.

RESULT

The clinical guide provides 79 recommendations for clinicians in the management of voice disorders during the pandemic and includes advice from assessment, direct treatment, telepractice, and teamwork. The consensus was reached 95% for all topics.

CONCLUSION

This guideline should be taken only as recommendation; each clinician must attempt to mitigate the risk of infection and achieve the best therapeutic results taking into account the patient's particular reality.

Voice Therapy in the Context of the COVID-19 Pandemic: Guidelines for Clinical Practice

INTRODUCTION

Since the beginning of the new pandemic, COVID-19 health services have had to face a new scenario. Voice therapy faces a double challenge, interventions using telepractice, and delivering rehabilitation services to a growing population of patients at risk of functional impairment related to the COVID-19 disease. Moreover, as COVID-19 is transmitted through droplets, it is critical to understand how to mitigate these risks during assessment and treatment.

OBJECTIVE

To promote safety, and effective clinical practice to voice assessment and rehabilitation in the pandemic COVID-19 context for speech-language pathologists.

METHODS

A group of 11 experts in voice and swallowing disorders from five different countries conducted a consensus recommendation following the American Academy of Otolaryngology-Head and Neck Surgery rules building a clinical guide for speech-language pathologists during this pandemic context.

RESULTS

The clinical guide provides 65 recommendations for clinicians in the management of voice disorders during the pandemic and includes advice from assessment, direct treatment, telepractice, and teamwork. The consensus was reached 95% for all topics.

CONCLUSION

This guideline should be taken only as recommendation; each clinician must attempt to mitigate the risk of infection and achieve the best therapeutic results taking into account the patient's particular reality.

Restoration Strategies Following Short-Term Vocal Exertion in Healthy Young Adults

Purpose This study aims to investigate the effects of a 10-min vocal exertion task on voice and respiratory measures, to determine whether restorative strategies can mitigate these effects after cessation of exertion, and to assess whether these strategies continue to reduce these detrimental effects when vocal exertion is resumed. Method A prospective, repeated-measures design was used. On consecutive days, 20 participants (equal men and women) completed two vocal exertion tasks separated by 10 min of restoration strategies: vocal rest or controlled phonation (low-level tissue mobilization using straw phonation). Voice and respiratory data were collected at baseline, following the first exertion task, after restoration strategies, and after the second exertion task. Outcome measures included (a) vocal effort, (b) phonation threshold pressure, (c) maximum and minimum fundamental frequencies, (d) cepstral peak prominence of connected speech, (e) lung volume initiation and termination, (f) percent vital capacity expended per syllable, and (g) number of syllables per breath group. Results A worsening of phonation threshold pressure (p < .001), vocal effort (p < .001), and increase of minimum fundamental frequency (p = .007) were observed after vocal exertion. Lung volume initiation (p < .001) and lung volume termination (p < .001) increased. These changes were largely reversed by restoration strategies, but only controlled phonation prevented exertion-induced changes in respiratory kinematic measures on a subsequent vocal exertion task. Conclusions Exertion-induced voice changes occur rapidly and may be mitigated by either controlled phonation or vocal rest. Controlled phonation is recommended as a superior strategy due to evidence of a protective effect on a successive vocal exertion task.

[Molecular laryngology : A new chapter in the understanding of laryngeal diseases]

BACKGROUND

Despite considerable advances in laryngological research, there is still a plethora of (benign) vocal fold pathologies that cannot be treated causally. This is due to the limited accessibility and sensitive microarchitecture of the vocal folds, which cannot be investigated at a cellular level. Consequently, current pathophysiological knowledge is frequently based on macroscopic findings. The impact of interventions is mainly evaluated endoscopically or via indirect diagnostic methods.

OBJECTIVE

The aim of this article is to discuss state-of-the-art biotechnological methods used in laryngological research, illustrated by practical examples.

RESULTS

In recent years, animal and in vitro experiments have significantly contributed to a continuous expansion of knowledge in this field, particularly regarding vocal fold inflammation and scar formation. Vocal fold fibroblasts, the most important cellular component of the lamina propria, can be accredited a central role in these processes.

CONCLUSION

Our knowledge regarding macroanatomy and macropathophysiology of several pathologies has increased considerably in recent years. In vitro trials have shown, e.g., that vocal fold fibroblasts in an inflammatory setting secrete less profibrotic and proinflammatory cytokines when exposed to vibration. Early vocal exercises after surgical interventions on the vocal folds may therefore promote better wound healing and consequently improved phonation. Research in molecular laryngology should create a solid basis of knowledge for subsequent clinical studies.

Vocalization with semi-occluded airways is favorable for optimizing sound production

Vocalization in mammals, birds, reptiles, and amphibians occurs with airways that have wide openings to free-space for efficient sound radiation, but sound is also produced with occluded or semi-occluded airways that have small openings to free-space. It is hypothesized that pressures produced inside the airway with semi-occluded vocalizations have an overall widening effect on the airway. This overall widening then provides more opportunity to produce wide-narrow contrasts along the airway for variation in sound quality and loudness. For human vocalization described here, special emphasis is placed on the epilaryngeal airway, which can be adjusted for optimal aerodynamic power transfer and for optimal acoustic source-airway interaction. The methodology is three-fold, (1) geometric measurement of airway dimensions from CT scans, (2) aerodynamic and acoustic impedance calculation of the airways, and (3) simulation of acoustic signals with a self-oscillating computational model of the sound source and wave propagation.

Phonogenic Voice Problems among Speech-Language Pathologists in Synchronous Telepractice: An Overview and Recommendations

Many speech-language pathologists (SLPs) recently adopted a live, synchronous online distribution of clinical services due to physical distancing measures aimed at bringing the coronavirus disease 2019 (COVID-19) outbreak under control. Few SLPs had received training in telepractice to prepare them for changes from an in-person service delivery model to synchronous telepractice. The new telepractice environment may alter vocal behaviors and communication interactions in such a way that negatively impacts voice production. Thus, delivering synchronous online clinical services may require that SLPs adopt novel prevention strategies for avoiding phonogenic voice problems. Guided by two complementary injury frameworks, the Haddon Matrix and the Haddon Countermeasures, this article provides an overview of potential factors associated with phonogenic voice problems among SLPs in telepractice and proposes possible prevention strategies to maintain optimal vocal health and function with synchronous modes of online clinical practice.

In vitro mechanical vibration down-regulates pro-inflammatory and pro-fibrotic signaling in human vocal fold fibroblasts

INTRODUCTION

Voice rest following phonotrauma or phonosurgery has a considerable clinical impact, but clinical recommendations are inconsistent due to inconclusive data. As biopsies of the vocal folds (VF) for molecular biology studies in humans are unethical, we established a new in vitro model to explore the effects of vibration on human vocal fold fibroblasts (hVFF) in an inflammatory and normal state, which is based on previously published models.

METHODS

By using a phonomimetic bioreactor we were able to apply predefined vibrational stress patterns on hVFF cultured under inflammatory or normal conditions. Inflammatory and pro-fibrotic stimuli were induced by interleukin (IL)1β and transforming growth factor (TGF)β1, respectively. Mechanical stimulation was applied four hours daily, over a period of 72 hours. Outcome measurements comprised assessment of extracellular matrix (ECM)-related components, angiogenic factors, and inflammatory and fibrogenic markers on gene expression and protein levels.

RESULTS

Under inflammatory conditions, the inflammatory cytokine IL11, as well as the myofibroblast marker alpha smooth muscle actin (α-SMA) were significantly reduced when additional vibration was applied. The desirable anti-fibrotic ECM component hyaluronic acid was increased following cytokine treatment, but was not diminished following vibration.

CONCLUSION

Our experiments revealed the effect of vibrational stress on hVFF in an inflammatory state. Elevated levels of certain pro-inflammatory/pro-fibrotic factors could be mitigated by additional vibrational excitation in an in vitro setting. These findings corroborate clinical studies which recommend early voice activation following an acute event.

Are Indoor Cycling Instructors Riding Their Way to Vocal Injury? Acute Effects of a Single Class on Measures of Voice Production

OBJECTIVE/HYPOTHESIS

There is an increased need for vocal education programs in group fitness instructors due to the reported risk of phonotraumatic injury in this population. Most research has focused on aerobics class instructors with limited research detailing the vocal demand response of cycling instruction, specifically. We hypothesized that instruction of a single indoor cycling class would produce evidence of acute vocal fold edema manifested by worsening of acoustic and self-perceptual voice measures and changes in ratings of laryngeal appearance.

STUDY DESIGN

Prospective Cohort study.

METHODS

Acoustic and self-perceptual voice measures that were potentially sensitive to laryngeal edema were collected from ten cycling instructors (Mean age: 31 ± 6.14 years, 3M and 7F) before and after instruction of a typical 45-minute cycling class. Two laryngologists then rated pairs of laryngeal exams from five instructors (Mean age: 30 ± 6.22 years, 1M and 4F) on the measure of vocal fold edema using a 10-inch Visual Analogue Scale. Paired t-test comparisons were completed on normalized data to compare pre- and postinstruction.

RESULTS

Majority of acoustic and self-perceptual measures significantly worsened following cycling instruction but the magnitude of change in these measures were small. In terms of laryngeal appearance, no measurable change in vocal fold edema was observed at both time points.

CONCLUSION

The vocal demand response to a single cycling class may be insufficient to cause significant vocal fold edema in our cycling instructors. Future research is required to determine the effects of repeated cycling instruction.

Continuous Rate Infusion of Ketamine Hydrochloride and Dexmedetomidine for Maintenance of Anesthesia during Laryngotracheal Surgery in New Zealand White Rabbits (Oryctolagus cuniculus)

New Zealand white rabbits (Oryctolagus cuniculus) are an established in vivo model for the study of structural and functional consequences of vocal-fold vibration. Research design requires invasive laryngotracheal procedures, and the presence of laryngospasms or pain responses (or both) hinder phonation-related data collection. Published anesthesia regimens report respiratory depression and muscle tone changes and have been unsuccessful in mitigating autonomic laryngeal responses in our protocol. Infusion of ketamine hydrochloride and dexmedetomidine hydrochloride in pediatric medicine provides effective analgesia and sedation for laryngotracheal procedures including intubation and bronchoscopy; however, data evaluating the use of ketamine-dexmedetomidine infusion in rabbits are unavailable. This study reports a new infusion regimen, which was used in 58 male New Zealand white rabbits that underwent a nonsurvival laryngotracheal procedure to induce phonotraumatic vocal-fold injury. Animals were sedated by using ketamine hydrochloride (20 mg/kg IM) and dexmedetomidine (0.125 mg/kg IM). Maintenance anesthesia was provided by using continuous rate intravenous infusion of ketamine hydrochloride (343 μg/kg/min) and dexmedetomidine (1.60 μg/kg/min). A stable plane of anesthesia with no autonomic laryngeal response (laryngospasm) was achieved in 32 of the 58 rabbits (55%). Laryngospasms occurred in 25 of 58 animals (43%) and were controlled in 20 cases (80%) by providing 0.33 mL 2% topical lidocaine, incremental increase in infusion rate, or both. Continuous rate infusion of ketamine hydrochloride-dexmedetomidine with prophylactic topical lidocaine provides a predictable and adjustable surgical plane of anesthesia, with minimal confounding respiratory and autonomic laryngeal responses, during extended-duration laryngotracheal surgery in rabbits. This regimen should be considered as an alternative to injection maintenance for prolonged, invasive procedures.

The Therapeutic Effects of Straw Phonation on Vocal Fatigue

OBJECTIVES

Straw phonation has been investigated for its vocal warm-up effects on healthy populations and therapeutic effects on voice patients. The purpose of this article was to determine whether it is beneficial for vocal fatigue.

STUDY DESIGN

Prospective cohort study METHODS: Twenty-five healthy participants were recruited into 1-hour vocal loading tasks followed by 10-minute vocal rest or straw phonation on 2 different days. Various parameters including phonation threshold pressure (PTP), mean airflow, closed quotient (CQ), current speaking effort level (EFFT), and laryngeal discomfort (DISC) were acquired at baseline, after vocal load, and after the intervention.

RESULTS

Increased PTP, EFFT, and DISC were observed after vocal load. Decreased PTP, EFFT, and DISC were then acquired after both vocal rest or straw phonation. More significant improvements were obtained in straw phonation when compared with vocal rest. Additionally, significantly increased mean flow and decreased CQ were obtained after straw phonation when compared to vocal rest.

CONCLUSIONS

Straw phonation has the potential to adjust aerodynamics within the vocal tract leading to improved vocal efficiency, optimized vibration mode, and attenuated vocal fatigue. This study provided a promising treatment for vocal fatigue that could have wide clinical relevance to voice users with high voice demands.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:E674-E679, 2020.

Development and validation of a novel phonomimetic bioreactor

Vocal fold fibroblasts (VFF) constitute the main cell type of the vocal fold’s lamina propria, produce the extracellular matrix and thereby determine the tissue characteristics. To study VFF behavior under in vitro conditions it is important to mimic the dynamic environment of the in vivo state. The aim of our study was to develop and validate a novel phonomimetic bioreactor system mainly based on commercially available components. The use of cell culture dishes with flexible silicone bottoms in combination with a suitable loudspeaker made it possible to expose the cells to various kinds of phonatory stimuli. The fundamental vibration characteristics of silicone membranes were investigated with and without cell culture medium by laser Doppler vibrometry. Human VFF were seeded in flexible-bottomed plates and placed in a custom-made housing containing a loudspeaker. After the cells were exposed to a predefined audio stimulation protocol, cell viability was assessed and gene as well as protein expression levels were compared to static controls. Laser Doppler vibrometry revealed that addition of cell culture medium changed the resonance frequencies of vibrating membranes. Gene expression of hyaluronan synthase 2, collagen III, fibronectin and TGFβ-1 was significantly upregulated in VFF exposed to vibration, compared to static control. Vibration also significantly upregulated collagen I gene and protein expression. We present a new type of phonomimetic bioreactor. Compared to previous models, our device is easy to assemble and cost-effective, yet can provide a wide spectrum of phonatory stimuli based on the entire dynamic range of the human voice. Gene expression data of VFF cultured in our phonomimetic bioreactor show a significant effect of vibration on ECM metabolism, which illustrates the efficacy of our device.

Mechanotransduction of vocal fold fibroblasts and mesenchymal stromal cells in the context of the vocal fold mechanome

The design of cell-based therapies for vocal fold tissue engineering requires an understanding of how cells adapt to the dynamic mechanical forces found in the larynx. Our objective was to compare mechanotransductive processes in therapeutic cell candidates (mesenchymal stromal cells from adipose tissue and bone marrow, AT-MSC and BM-MSC) to native cells (vocal fold fibroblasts-VFF) in the context of vibratory strain. A bioreactor was used to expose VFF, AT-MSC, and BM-MSC to axial tensile strain and vibration at human physiological levels. Microarray, an empirical Bayes statistical approach, and geneset enrichment analysis were used to identify significant mechanotransductive pathways associated with the three cell types and three mechanical conditions. Two databases (Gene Ontology, Kyoto Encyclopedia of Genes and Genomes) were used for enrichment analyses. VFF shared more mechanotransductive pathways with BM-MSC than with AT-MSC. Gene expression that appeared to distinguish the vibratory strain condition from polystyrene condition for these two cells types related to integrin activation, focal adhesions, and lamellipodia activity, suggesting that vibratory strain may be associated with cytoarchitectural rearrangement, cell reorientation, and extracellular matrix remodeling. In response to vibration and tensile stress, BM-MSC better mimicked VFF mechanotransduction than AT-MSC, providing support for the consideration of BM-MSC as a cell therapy for vocal fold tissue engineering. Future research is needed to better understand the sorts of physical adaptations that are afforded to vocal fold tissue as a result of focal adhesions, integrins, and lamellipodia, and how these adaptations could be exploited for tissue engineering.

Absolute or relative voice rest after phonosurgery: a blind randomized prospective clinical trial

OBJECTIVES

The first aim, was to compare participant compliance with postoperative voice rest advice in two groups. The second aim was to compare vocal function and recovery in the short-term, seven days post-surgery and in the long-term, 3-6 months post-surgery.

DESIGN

Preliminary randomized prospective blind clinical trial.

METHODS

Twenty patients scheduled for surgery for benign vocal fold lesions were randomized into seven days of absolute or relative voice rest. Compliance with voice rest advice was monitored with a voice accumulator for seven days following surgery. Vocal recovery was tracked through (a) self-perceived vocal function, (b) perceptual assessments of voice recordings and (c) visual assessment of high resolution and high speed digital imaging (d) vocal stamina and reaction to vocal loading, explored with a vocal loading task.

RESULTS

The absolute voice rest group phonated significantly less than the relative voice rest group during seven days post-surgery, but they were not silent. The absolute voice rest group self-reported more difficulty with compliance than the relative voice rest group. The relative voice rest group coped with significantly more vocal loading at long-term check-up. In the short-term the absolute voice rest group improved morphological recovery to a significant degree, however relative voice rest renders superior long-term recovery.

CONCLUSIONS

Absolute voice rest is difficult to comply with. Neither short-term, nor long-term vocal recovery differed significantly between groups. Within-group comparisons showed significant improvements in vocal stamina, immediate recovery from vocal loading and self-assessments of voice problems only for the group with recommended relative voice rest.

High-Performance Agent-Based Modeling Applied to Vocal Fold Inflammation and Repair

Fast and accurate computational biology models offer the prospect of accelerating the development of personalized medicine. A tool capable of estimating treatment success can help prevent unnecessary and costly treatments and potential harmful side effects. A novel high-performance Agent-Based Model (ABM) was adopted to simulate and visualize multi-scale complex biological processes arising in vocal fold inflammation and repair. The computational scheme was designed to organize the 3D ABM sub-tasks to fully utilize the resources available on current heterogeneous platforms consisting of multi-core CPUs and many-core GPUs. Subtasks are further parallelized and convolution-based diffusion is used to enhance the performance of the ABM simulation. The scheme was implemented using a client-server protocol allowing the results of each iteration to be analyzed and visualized on the server (i.e., in-situ) while the simulation is running on the same server. The resulting simulation and visualization software enables users to interact with and steer the course of the simulation in real-time as needed. This high-resolution 3D ABM framework was used for a case study of surgical vocal fold injury and repair. The new framework is capable of completing the simulation, visualization and remote result delivery in under 7 s per iteration, where each iteration of the simulation represents 30 min in the real world. The case study model was simulated at the physiological scale of a human vocal fold. This simulation tracks 17 million biological cells as well as a total of 1.7 billion signaling chemical and structural protein data points. The visualization component processes and renders all simulated biological cells and 154 million signaling chemical data points. The proposed high-performance 3D ABM was verified through comparisons with empirical vocal fold data. Representative trends of biomarker predictions in surgically injured vocal folds were observed.

The 2016 G. Paul Moore Lecture: Lessons in Voice Rehabilitation: Journal of Voice and Clinical Practice

This Paul Moore Lecture honors the contributions made by authors to the Journal of Voice during a period of 30 years, from 1987. Fifty articles were selected and included under the following five topics: (1) normalcy of the larynx and voice; (2) the clinical speech-language pathologist's evaluation; (3) the patient's perspective; (4) the core of vocal rehabilitation; and (5) behavioral versus organic dysphonias. The analysis reflects a vivid landscape of the specific area and significant advances in knowledge. It also shows the valuable interdependence between science and clinical practice. The topics highlight the following information: (1) The physical appearance of a healthy larynx varies across individuals with normal voices. (2) The voice is not a binary descriptor (normal versus abnormal) but a variable measure, with many cultural influences on the perceptual auditory analysis of a voice. (3) The clinical speech-language pathologist assessment is multidimensional and multiparametric, with both subjective and objective analyses. The patients' opinion about the impact of a voice problem on his or her quality of life is significant when proposing a treatment. Therefore, it is also included in the initial assessment. (4) Vocal rehabilitation is a nonlinear process that combines direct and indirect approaches. Evidence of the positive effect of voice therapy is now well established. (5) Behavioral dysphonias may be linked to self-regulation of the use of voice and this needs to be taken into consideration. Although organic dysphonias are not necessarily the result of harmful vocal behaviors, they too can benefit from vocal rehabilitation.

Short-Term Effect of Two Semi-Occluded Vocal Tract Training Programs on the Vocal Quality of Future Occupational Voice Users: "Resonant Voice Training Using Nasal Consonants" Versus "Straw Phonation"

PURPOSE

The purpose of this study was to determine the short-term effect of 2 semi-occluded vocal tract training programs, "resonant voice training using nasal consonants" versus "straw phonation," on the vocal quality of vocally healthy future occupational voice users.

METHOD

A multigroup pretest-posttest randomized control group design was used. Thirty healthy speech-language pathology students with a mean age of 19 years (range: 17-22 years) were randomly assigned into a resonant voice training group (practicing resonant exercises across 6 weeks, n = 10), a straw phonation group (practicing straw phonation across 6 weeks, n = 10), or a control group (receiving no voice training, n = 10). A voice assessment protocol consisting of both subjective (questionnaire, participant's self-report, auditory-perceptual evaluation) and objective (maximum performance task, aerodynamic assessment, voice range profile, acoustic analysis, acoustic voice quality index, dysphonia severity index) measurements and determinations was used to evaluate the participants' voice pre- and posttraining. Groups were compared over time using linear mixed models and generalized linear mixed models. Within-group effects of time were determined using post hoc pairwise comparisons.

RESULTS

No significant time × group interactions were found for any of the outcome measures, indicating no differences in evolution over time among the 3 groups. Within-group effects of time showed a significant improvement in dysphonia severity index in the resonant voice training group, and a significant improvement in the intensity range in the straw phonation group.

CONCLUSIONS

Results suggest that the semi-occluded vocal tract training programs using resonant voice training and straw phonation may have a positive impact on the vocal quality and vocal capacities of future occupational voice users. The resonant voice training caused an improved dysphonia severity index, and the straw phonation training caused an expansion of the intensity range in this population.

Voice rest after laryngeal surgery: what's the evidence?

PURPOSE OF REVIEW

This article aims to review previous research reports and to summarize current strategies for the optimal duration of voice rest and the effect of phonatory stimulation after phonomicrosurgery.

RECENT FINDINGS

Voice rest is commonly recommended after laryngeal surgery to prevent worsening of vocal fold injuries. However, there are no established standard protocol for voice rest, and the type and duration of voice rest vary among clinicians. The most effective duration of voice rest is unknown. Recently, early vocal stimulation was recommended as a means to improve wound healing, on the basis of the basic and clinical researches.

SUMMARY

It seems that early vocal stimulation may enhance the wound healing process in the vocal fold. More basic and clinical researches are warranted to investigate appropriate timing of initiation of stimulation, as well as the type and amount of stimulation that are available for human.

Elementary School Teachers' Vocal Dose: Muscle Bioenergetics and Training Implications

PURPOSE

Translating exercise-science methodology for determination of muscle bioenergetics, we hypothesized that the temporal voice-use patterns for classroom and music teachers would indicate a reliance on the immediate energy system for laryngeal skeletal-muscle metabolism. It was hypothesized that the music-teacher group would produce longer voiced segments than the classroom teachers.

METHOD

Using a between- and within-group multivariate analysis-of-variance design (5 classroom teachers; 7 music teachers), we analyzed fundamental-frequency data-collected via an ambulatory phonation monitor-for length (seconds) of voiced and nonvoiced intervals. Data were collected for 7.5 hr during the workday, over the course of several workdays for each teacher.

RESULTS

Descriptive analyses of voiced and nonvoiced intervals indicated that over 99% of voiced segments for both groups were no longer than 3.15 s, supporting the hypothesis of reliance on the immediate energy system for muscle bioenergetics. Significant differences were identified between and within the classroom- and music-teacher groups, with the music-teacher group producing longer voiced segments overall.

CONCLUSIONS

Knowledge of probable intrinsic laryngeal skeletal-muscle bioenergetics requirements could inform new interdisciplinary considerations for voice habilitation and rehabilitation.

Muscle Bioenergetic Considerations for Intrinsic Laryngeal Skeletal Muscle Physiology

PURPOSE

Intrinsic laryngeal skeletal muscle bioenergetics, the means by which muscles produce fuel for muscle metabolism, is an understudied aspect of laryngeal physiology with direct implications for voice habilitation and rehabilitation. The purpose of this review is to describe bioenergetic pathways identified in limb skeletal muscle and introduce bioenergetic physiology as a necessary parameter for theoretical models of laryngeal skeletal muscle function.

METHOD

A comprehensive review of the human intrinsic laryngeal skeletal muscle physiology literature was conducted. Findings regarding intrinsic laryngeal muscle fiber complement and muscle metabolism in human models are summarized and exercise physiology methodology is applied to identify probable bioenergetic pathways used for voice function.

RESULTS

Intrinsic laryngeal skeletal muscle fibers described in human models support the fast, high-intensity physiological requirements of these muscles for biological functions of airway protection. Inclusion of muscle bioenergetic constructs in theoretical modeling of voice training, detraining, fatigue, and voice loading have been limited.

CONCLUSIONS

Muscle bioenergetics, a key component for muscle training, detraining, and fatigue models in exercise science, is a little-considered aspect of intrinsic laryngeal skeletal muscle physiology. Partnered with knowledge of occupation-specific voice requirements, application of bioenergetics may inform novel considerations for voice habilitation and rehabilitation.

A systematic review of resonant voice therapy

PURPOSE

The purpose of this study is to systematically review the literature on resonant voice therapy and to evaluate the level of evidence on the effectiveness of using resonant voice therapy in treating dysphonia.

METHOD

Refereed journal papers from 1974 to 2014 were retrieved and reviewed by two independent reviewers using the keywords "Humming, Resonance, Resonant Voice, Semi-occluded or closed tube phonation" using available database systems. Quality of evidence was evaluated by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULT

Thirteen papers met the search criteria. Nine papers were selected by the two reviewers. Two of the papers were randomised-controlled studies and the other seven were observational studies. At least four types of resonant voice therapies were described. They included the Lessac-Madsen Resonant Voice Therapy, Y-Buzz, Resonance Therapy and Humming. The overall level of quality of evidence was graded as "moderate".

CONCLUSION

There were limited studies that investigated the effectiveness of resonant voice therapy. Most studies were small-scale uncontrolled observational studies with the inclusion of only small samples or specific populations. There is clearly a need for more large-scale randomised controlled studies with a wider range of populations to provide further evidence on the effectiveness of resonant voice training for different populations.

Real-Time Agent-Based Modeling Simulation with in-situ Visualization of Complex Biological Systems: A Case Study on Vocal Fold Inflammation and Healing

We present an efficient and scalable scheme for implementing agent-based modeling (ABM) simulation with In Situ visualization of large complex systems on heterogeneous computing platforms. The scheme is designed to make optimal use of the resources available on a heterogeneous platform consisting of a multicore CPU and a GPU, resulting in minimal to no resource idle time. Furthermore, the scheme was implemented under a client-server paradigm that enables remote users to visualize and analyze simulation data as it is being generated at each time step of the model. Performance of a simulation case study of vocal fold inflammation and wound healing with 3.8 million agents shows 35× and 7× speedup in execution time over single-core and multi-core CPU respectively. Each iteration of the model took less than 200 ms to simulate, visualize and send the results to the client. This enables users to monitor the simulation in real-time and modify its course as needed.

Factors Associated With Attrition in Randomized Controlled Trials of Vocal Rehabilitation: Systematic Review and Meta-Analysis

OBJECTIVES/HYPOTHESIS

This study aimed to determine the dropout rates and the reasons for dropout in randomized clinical trials of vocal rehabilitation.

STUDY DESIGN

This study used systematic review and meta-analysis (CRD42013003807).

METHODS

We included randomized controlled trials for voice disorders. In June 2015, we searched the following databases: MEDLINE, EMBASE, Cochrane, Clinical Trials, and AJSLP. The titles and abstracts or full texts of articles were independently analyzed by two reviewers. Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) scale. Our initial research base included more than 8491 articles.

RESULTS

A total of 51 articles were obtained using our eligibility criteria. The low-quality studies evaluated had higher dropout rates (odds ratio: 3.3, 95% confidence interval: 1.04-12.9). Studies with healthy patients (45%) or vocal training versus no training (25%) also had higher dropout rates. Methodological issues seemed to have a greater influence on the dropout rates of the studies included in the co-occurrence matrix.

CONCLUSIONS

Dropout rates of approximately 15% occur in randomized clinical trials of speech therapy when assessed by the Grading of Recommendations Assessment, Development and Evaluation. Studies with lower methodological quality had higher patient loss rates. Methodological and clinical reasons accounted for the highest dropout rates in the studies included in this meta-analysis.

Terapia vocal e sons nasais: efeitos sobre disfonias hiperfuncionais

RESUMO Buscou-se verificar os efeitos de um programa fonoterapêutico que incluiu orientação vocal e postural, adequação da função respiratória e a técnica de sons nasais em disfonias hiperfuncionais. Foi realizado um estudo de casos clínicos, observacional, longitudinal, não controlado, de caráter quantitativo que analisou três sujeitos do sexo feminino com idade média de 31,33 anos que apresentavam disfonias hiperfuncionais. Os sujeitos foram submetidos a: videolaringoscopia, avaliação vocal perceptivoauditiva e acústica, coleta de tempos máximos de fonação, triagem postural e determinação do tipo respiratório durante a fala, antes e após um programa terapêutico composto por orientação, conscientização e treinamento vocal com sons nasais durante 16 sessões de fonoterapia, uma vez na semana com treinamento em domicílio. Os dados foram analisados por meio dos testes não-paramétricos Mann-Whitney e Qui-quadrado, com nível de significância de 5%. Pós-terapia, observou-se que a postura corporal passou de desalinhada para alinhada e o tipo respiratório de superior para costodiafragmático abdominal; houve diminuição das medidas acústicas em relação ao grau e número de subharmônicos na maioria significante dos sujeitos, além de melhoras teciduais e diminuição do edema na mucosa das pregas vocais e na região aritenoide, e melhora da coaptação glótica. Após a execução de um programa fonoterapêutico com orientação vocal e postural, adequação da função respiratória e uso da técnica de sons nasais em disfonias hiperfuncionais, observou-se melhora significante da postura corporal, do tipo respiratório, das medidas acústicas sugestivas de ruído à emissão vocal, e efeitos positivos sobre o tecido e o fechamento das pregas vocais.