The Effect of Hydration on Voice Quality in Adults: A Systematic Review

Vocal Hygiene: What Are Professional Voice Users Saying About It on YouTube?

PURPOSE

Health content has been presented and accessed freely on social networks and can generate misinformation; hence, this study aimed to analyze the voice guidance in videos available on YouTube.

METHOD

This observational cross-sectional research selected the 45 most-viewed videos on YouTube in 2022, produced by professional voice users with guidance on vocal hygiene and well-being. The content was described and compared with the scientific literature on the topic, analyzing which category of professional voice users produced the most scientifically based content.

RESULTS

Altogether, 38 topics were found in the videos, distributed in nine blocks, identified from A to I. Block A (foods with a positive effect on the voice) was the only one that had no citations in scientific articles, whereas block D (negative habits for the voice) had the highest mean number of articles in relation to the others. The most publicized guidelines were mainly related to actions and/or behaviors and resources considered positive for the voice. Eight professional categories were found who produced these videos. Singing teachers who also worked as singers produced the most scientifically based content.

CONCLUSION

The study showed that not all the information in the videos was scientifically based, which means that people with voice problems have easy access to information that could even harm them if used in their professions.

Toward Sham Interventions for Behavioral Voice Treatment Outcome Research in Female Students Without Dysphonia

OBJECTIVES/HYPOTHESIS

To develop sham voice treatment techniques to be used in voice treatment outcome research, and to investigate their effectiveness as sham. This entails that the techniques induce no changes in voice or voice physiology, yet still lead to a perception of efficacy.

STUDY DESIGN

Prospective randomized blinded controlled study.

METHODS

Three distinct sham intervention protocols (SIPs) were conceptualized as placebic comparators for three common voice treatment approaches with focus on vocalization (SIP1), respiration (SIP2), and manipulation (SIP3). Forty-eight female students participated in the study. Each participant attended ten 30-minute sessions over 5weeks, including a baseline evaluation, three sessions of one SIP, an inter-SIP voice assessment, three sessions of a second SIP, and a final post-SIP assessment. Auditory-perceptual and instrumental voice evaluations were used as voice treatment outcome measures. The participants' perception of voice-related quality of life was evaluated using the French Voice Handicap Index (VHIFR). Frequentist as well as Bayesian statistical methods were applied for group comparisons. The effects of combining two SIPs, the potential influence of SIP order, and experimenter/clinician effects, were also investigated.

RESULTS

The respiration-based SIP2 showed changes only in sound intensity level on a sustained vowel across the three sham intervention sessions. In contrast, the vocalization-based SIP1 impacted sound intensity level on a sustained vowel, sound intensity level on read text, and maximum phonation time. The manipulation-based SIP3 affected smoothed cepstral peak prominence on read text, Acoustic Voice Quality Index, and Dysphonia Severity Index. SIP2 thus demonstrated the highest alignment with the study's objectives, followed by SIP1 and SIP3. GRBASI ratings revealed no statistical differences for any SIP. VHIFr decreased significantly after all three SIPs. Combining the SIPs generally replicated the effects observed when each SIP was used individually. There was no order effect or experimenter/clinician effect on the results.

CONCLUSIONS

This study demonstrated significant changes in participants' perceived voice quality (measured with VHIFr) across various SIPs, despite minimal impact on objective voice function measures. Further investigation is necessary to establish one or more protocols as genuinely sham interventions.

Water Versus Electrolyte Rehydration on Vocal Fold Osmotic and Oxidative Stress Gene Expression

OBJECTIVES

Systemic dehydration may induce osmotic and oxidative stress in the vocal folds, but our knowledge of the biology and mitigation with rehydration is limited. The purpose of this experiment was to evaluate whether systemic dehydration induces vocal fold oxidative and osmotic stress and to compare the impact of rehydration by water intake versus electrolyte intake on osmotic and oxidative stress-related gene expression.

METHODS

Four-month-old male Sprague-Dawley rats (N = 32) underwent water restriction. Rehydration was achieved with ad libitum access to water or electrolytes for 24 hours. Rats were divided into four groups: euhydration control, dehydration-only, dehydration followed by either water or electrolyte rehydration (n = 8/group). Gene expression was assessed via RT2 Gene Expression Profiler arrays.

RESULTS

With respect to oxidative stress, 10 genes were upregulated and 2 were downregulated after vocal fold dehydration compared with the euhydrated control. Concerning osmotic stress, six genes were upregulated with dehydration only, six genes were upregulated following rehydration with water, whereas a single gene was upregulated with electrolyte rehydration. All genes with significantly different expression between the rehydration groups showed lower expression with electrolytes compared with water.

CONCLUSIONS

The results support a potential role of oxidative and osmotic stresses in vocal folds related to systemic dehydration. The differences in stress-related gene expression in vocal fold tissue between rehydration with electrolytes or water, albeit modest, suggest that both rehydration options offer clinical utility to subjects experiencing vocal fold dehydration with preliminary evidence that electrolytes may be more effective than water in resolving osmotic stress.

LEVELS OF EVIDENCE

NA (prospective animal study) Laryngoscope, 2024.

Self-reported voice difficulties in educational professionals during COVID-19 in Quebec: a cross-sectional mixed-methods study

Background: The health measures imposed by COVID-19 on workplaces created adverse communication settings. Our cross-sectional study aimed to document the nature and severity of the vocal difficulties experienced by educational professionals a few weeks after the implementation of health measures in schools and early childhood settings in Quebec, Canada while teaching in class.Methods: To this end, we conducted a self-report survey containing nine close-ended questions and one open-ended question regarding self-reported vocal difficulties and the implementation of health measures. The survey was answered by 194 educational professionals in October 2020.Results: Since the introduction of the health measures, respondents reported often or always: having difficulty making themselves heard (66.5%), needing to strain their voice (68.1%), having throat pain after work (38.1%), and being concerned about their vocal health (25.2%). 35.6% perceived that their voice changed moderately or a lot and 75.3% did not feel equipped to take care of their vocal health. Fisher's exact tests revealed the difficulties overall were more present in women (p < 0.05).Discussion: The qualitative analysis of open-ended question answers shows a circular process at play, where the vocal responses to the COVID-19-induced communication barriers contribute to creating more problematic communication settings, thus increasing the challenges for vocal health. Better equipping the professionals to take care of their vocal health by developing resources in their professional settings to help them face vocal challenges in both every day as well as extreme situations, should be a priority.

Developing Educational Health Modules to Improve Vocal Wellness in Mask-Wearing Occupational Voice Users

OBJECTIVE

To develop educational modules to improve vocal wellness and optimize communication in mask-wearing occupational voice users.

METHODS

Module development focused on identifying accurate, understandable, and actionable steps to improve vocal wellness in the workplace. We i) interviewed eight voice-specialized speech-language pathologists and researchers on current speech and voice recommendations for mask-wearers, ii) developed educational content using the standardized Patient Education Materials Assessment Tool (PEMAT), iii) assessed the ability of nine mask-wearing community members to learn educational content, and iv) compared behavioral, acoustical, and perceptual changes in four mask-wearing healthcare professionals following educational training.

RESULTS

We created three educational modules that described key vocal health and communication strategies, including microphone amplification, postural alignment, clear speech, hydration, vocal naps, and vocal warm-ups. PEMAT scores were 96% and 93% on understandability and actionability, respectively. Mask-wearing healthcare professionals increased use of 4 out of the 6 strategies following educational training and were able to retain information at rates >90% at 1-week follow-up.

CONCLUSIONS

We developed a set of free-to-use educational modules to promote vocal wellness among mask-wearing occupational voice users (see VSMechLab.com). Future work should examine the impact of these strategies on voice measures in a larger group of mask-wearing community members.

Vocal Health Care amongst Hindustani Classical Singers- A Mixed Methods, Cross-Sectional Survey

OBJECTIVES

The objective of the present survey was to profile the knowledge, attitude, and practices towards vocal health care amongst Hindustani classical singers.

STUDY DESIGN

Mixed-methods, cross-sectional questionnaire-based study.

METHODS

A self-reported questionnaire was developed and used to gather data on the knowledge, attitude, and practices of Hindustani classical singers towards vocal health care. An online survey link was generated, and responses were collected from self-identified trained Hindustani classical singers. Descriptive statistics was carried out for the closed-ended questions and inductive approach was used to analyse the responses of open-ended questions.

RESULTS

Ninety-four self-identified trained Hindustani classical singers participated in the study. The responses indicate good knowledge towards vocal health measures and positive attitudes towards vocal health care. The open-ended responses were analysed using an inductive approach. Although, 70% were aware about role of a speech language pathologist, only 9.7% reported of consulting one in the event of voice problem. Further, 70% singers reported of following precautions to avoid voice problems while 85.1% considered voice rest as necessary before a performance. The singers reported of using home remedies, vocal and non-vocal measures as a part of vocal health measures.

CONCLUSIONS

The present study helps to profile the knowledge, attitude, and practices towards vocal health care amongst Hindustani classical singers. It also helps to provide a basis for further studies to establish an empirical basis for the reported practices towards vocal health care.

Computational Study of the Impact of Dehydration-Induced Vocal Fold Stiffness Changes on Voice Production

OBJECTIVE

Systemic vocal fold dehydration is known to increase vocal fold stiffness, which has been hypothesized to have important effect on voice production. However, it remains unclear whether the dehydration-induced vocal fold stiffness changes can have a noticeable impact on phonation, particularly in normal phonation conditions. The goal of this study was to investigate the impact of vocal fold stiffness changes due to vocal fold systemic dehydration and its significance in daily communication.

METHODS

Parametric computational simulation using a three-dimensional vocal fold model, in which the vocal fold stiffness was varied as a function of systemic dehydration levels based on previously-reported experimental data.

RESULTS

The results showed that systemic dehydration had significant effects on voice production only at high levels of dehydration, at which dehydration increased the phonation threshold pressure and fundamental frequency, and decreased glottal opening area, vocal intensity and glottal efficiency. The effect depended mainly on the overall dehydration level but was also slightly affected by the dehydration distribution and muscular control. However, for dehydration levels typical of normal phonation conditions, the effect was negligible.

CONCLUSIONS

The results indicated that dehydration-induced vocal fold stiffness change likely is not an important mechanism through which vocal fold systemic dehydration affects voice production. Nevertheless, a large decrease in glottal efficiency implies a possible perceived increase of vocal effort under a realistic dehydration condition.

Effect of Nebulization on Laryngeal Parameters: Analysis Using High-Speed Digital Videolaryngoscopy

INTRODUCTION

Superficial laryngeal hydration, obtained through nebulization, is related to the moisture level on the epithelial surfaces of the vocal folds, modifying their biomechanical and aerodynamic properties. Through high-speed videolaryngoscopy it is possible to obtain objective data for laryngeal analysis after nebulization and a better understanding of this phenomenon OBJECTIVE: To verify the effects of nebulization with saline solution on laryngeal parameters of digital videokymography obtained by high-speed videolaryngoscopy examination in women and men with and without laryngeal alterations METHOD: This is a clinical, comparative intra-subject study. Fifty-nine adults were selected, with and without laryngeal alterations, 30 females and 29 males. Digital videokymographs in the anterior, middle and posterior thirds of the vocal folds of the participants were analyzed before and after nebulization with 0.9% saline solution.

RESULTS

Women without laryngeal alterations showed more parameters changes after nebulization, in which there was a decrease in maximum and medium opening, amplitude of opening of the left and right vocal fold in the anterior glottal third, and an increase of the percentage of closure of the vocal folds. These results indicate a minor extent of lateral excursion of the vocal folds during phonation. In women with laryngeal alterations, the parameters that changed after nebulization were the increased frequency of opening of the left and right vocal folds in the topography of the posterior third. In men, nebulization did not change the variables studied, except for the amplitude of the right vocal fold in men with laryngeal alterations, in the analysis of the posterior glottic third.

CONCLUSION

The results suggest that surface hydration modifies laryngeal dynamics differently between genders. After nebulization with saline solution, women without laryngeal alterations showed a decrease in the lateralization of the vocal folds during phonation, suggesting a better phonatory efficiency.

Effectiveness of Thymepearls After Vocal Loading in Professional Voice Users: A Randomized Placebo-Controlled Double-Blind Clinical Trial

OBJECTIVES

Professional voice users depend on their voice for optimal performance of their profession. The aim of this study was to find out to what extent sucking a placebo and thyme represent an improvement of the voice in professional voice users after vocal loading.

METHODS

A randomized placebo-controlled clinical double-blind study was conducted with four measurement moments: a premeasurement, immediately after the vocal loading, after the subsequent ingestion of the "thymepearl" (TP) in the experimental group and in the control group the placebo, and after a half-hour break. Finally, 18 subjects were considered, 9 participants in each group.

RESULTS

No significant differences in the objective measurements of both groups could be observed. However, significant improvements in subjective measures (perceptions of dry mouth and feeling of hoarseness) could be observed after vocal loading by sucking the thymepearls in direct comparison to the placebo.

CONCLUSIONS

Sucking the TP can improve subjective sensation after vocal loading compared with placebo, but no differences are seen on objective vocal measures.

Nil per os in the management of oropharyngeal dysphagia-exploring the unintended consequences

Nil per os (NPO), also referred to as Nil by Mouth (NBM), is a health-related intervention of withholding food and fluids. When implemented in the context of a person with dysphagia, NPO aims to mitigate risks of aspiration. However, evidence demonstrating that NPO is beneficial as an intervention for people with dysphagia is lacking. This paper explores the theoretical and empirical evidence relating to the potential benefits and adverse effects of NPO and asserts that NPO is not a benign intervention. This paper argues for applying an ethics framework when making decisions relating to the use of NPO as an intervention for dysphagia, in particular addressing informed consent and a person's right to self-determination.

Prevalence of Complementary and Alternative Medicine Use in Professional Voice Users

Objectives To determine the prevalence and specific modalities of complementary and alternative medicine (CAM) by professional voice users (PVUs) for vocal ailments and to examine the PVU's health care utilization. Methods A Canadian national cross-sectional survey was conducted. Surveys were distributed electronically to members of the Alliance of Canadian Cinema, Television, and Radio Artists; the National Association of Teachers of Singing; the Canadian Actors Equity Association; and the Department of Vocal Performance at Western University. Participants were asked about the products/therapies they use to improve vocal health. Frequency of use, health care utilization, and general influencers in treatment choice were also collected. Results Two hundred eighty-eight participants completed the survey. 86% of participants claimed to have taken at least one form of CAM when experiencing voice loss or a negative voice change. Of the respondents, 18% claimed to use products/therapies for vocal health routinely in the absence of vocal ailments. The most common CAMs used were hot drinks with honey and/or lemon, lozenges, and inhaling steam. When vocally ill, PVUs were significantly more likely to use CAMs than any other treatment method. Voice teachers and medical doctors most commonly influenced the choice of the treatment. Conclusion This study illustrated the substantial prevalence of CAMs in the PVU community. Understanding the utilization of CAMs can help clinicians navigate treatment strategies for this patient population.

Noninvasive Management of Voice Disorders: An Umbrella Review

OBJECTIVES

The aim of this study was to assess published systematic reviews that discussed noninvasive management of voice disorders. An umbrella review was conducted to collect, organize, and summarize narratively all available pharmacologic and voice therapy interventions.

STUDY DESIGN

Umbrella review of systematic reviews.

METHODS

Pertinent systematic reviews were identified by searching Pubmed/Medline and Embase. A primary screen identified studies related to voice. The second round of screening focused on studies that involved noninvasive management of voice disorders such as pharmacologic or voice therapy interventions. Variables of interest included study design, number of studies included in the review, target population, method of intervention, and outcomes.

RESULTS

Forty-three systematic reviews were eligible and included in the umbrella review. Ten studies focused on pharmacologic interventions, and 33 studies focused on voice therapy. Individual studies included in the systematic reviews ranged from 2-47, with a total of 601 studies overall.

CONCLUSIONS

This study provides a detailed review of all available systematic reviews on noninvasive management of voice disorders. Explored medications included proton pump inhibitors, calcium channel blockers, tricyclic antidepressants, antibiotics, corticosteroids, and hormone replacement. Explored voice therapy techniques included hydration, vocal function exercises, laryngeal manual therapy, respiratory exercise, biofeedback, phonation, coping strategies, and others. This may be utilized to guide therapeutic decision-making and identify current gaps in the literature that may warrant future investigation.

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.

Validating the efficacy and value proposition of mental fitness vocal biomarkers in a psychiatric population: prospective cohort study

Background

The utility of vocal biomarkers for mental health assessment has gained increasing attention. This study aims to further this line of research by introducing a novel vocal scoring system designed to provide mental fitness tracking insights to users in real-world settings.

Methods

A prospective cohort study with 104 outpatient psychiatric participants was conducted to validate the "Mental Fitness Vocal Biomarker" (MFVB) score. The MFVB score was derived from eight vocal features, selected based on literature review. Participants' mental health symptom severity was assessed using the M3 Checklist, which serves as a transdiagnostic tool for measuring depression, anxiety, post-traumatic stress disorder, and bipolar symptoms.

Results

The MFVB demonstrated an ability to stratify individuals by their risk of elevated mental health symptom severity. Continuous observation enhanced the MFVB's efficacy, with risk ratios improving from 1.53 (1.09-2.14, p=0.0138) for single 30-second voice samples to 2.00 (1.21-3.30, p=0.0068) for data aggregated over two weeks. A higher risk ratio of 8.50 (2.31-31.25, p=0.0013) was observed in participants who used the MFVB 5-6 times per week, underscoring the utility of frequent and continuous observation. Participant feedback confirmed the user-friendliness of the application and its perceived benefits.

Conclusions

The MFVB is a promising tool for objective mental health tracking in real-world conditions, with potential to be a cost-effective, scalable, and privacy-preserving adjunct to traditional psychiatric assessments. User feedback suggests that vocal biomarkers can offer personalized insights and support clinical therapy and other beneficial activities that are associated with improved mental health risks and outcomes.

Behind the Headset: Predictive Accuracy of Patient-Reported Outcome Measures for Voice Symptoms in Call Centers

Objective

This study examines factors predicting self-reported voice symptoms in call center workers.

Methods

Multivariate analysis and predictive modeling assess personal, work-related, acoustic, and behavioral factors. Generalized Linear Models (GLMs) and Receiver Operating Characteristic (ROC) curves are employed.

Results

Age and sleep patterns impacted voice quality and effort, while workplace factors influenced symptom perception. Unhealthy vocal behaviors related to tense voice and increased effort, while hydration was protective. Voice acoustics showed diagnostic potential, supported by ROC data. These findings emphasize voice symptom complexity in call center professionals, necessitating comprehensive assessment.

Limitations

This study recognizes its limitations, including a moderate-sized convenience sample and reliance on PROM metrics. Future research should incorporate more objective measures in addition to self-reports and acoustic analysis.

Value

This research provides novel insights into the interplay of personal, occupational, and voice-related factors in developing voice symptoms among call center workers. Predictive modeling enhances risk assessment and understanding of individual susceptibility to voice disorders.

Conclusion

Results show associations between various factors and self-reported voice symptoms. Protective factors include sleeping more than six hours and consistent hydration, whereas risk factors include working conditions, such as location and behaviors like smoking. Diagnostic models indicate good accuracy for some voice symptom PROMs, emphasizing the need for comprehensive models considering work factors, vocal behaviors, and acoustic parameters to understand voice issues complexity.

The Efficacy of the NHS Waterpipe in Superficial Hydration for People With Healthy Voices: Effects on Acoustic Voice Quality, Phonation Threshold Pressure and Subjective Sensations

OBJECTIVES

This study examined the efficacy of the NHS waterpipe as a superficial hydration treatment in voice production in healthy young women.

STUDY DESIGN

This is a prospective, single-blind, within- and between-subject experimental design.

METHODS

Thirty six female university students (mean age 24.6 years, range 19-45 years) were recruited to the study. Participants were randomized to two experimental groups (E1 and E2) and a control group. E1 underwent hydration treatment with the NHS waterpipe filled with 0.9% saline that was immersed in a cup of heated water. E2 underwent a similar treatment but without heated immersion. The control group received no treatment. Acoustic Voice Quality Index (AVQI v03.01) and its subparameters, phonation threshold pressure, self-perceived phonatory effort and sensation of throat dryness was measured at three time points (before the intervention and immediately and 15 minutes after it).

RESULTS

The Tilt of the AVQI's subparameters increased significantly in the E1 (P = 0.027) and E2 groups (P = 0.027) after the intervention. Furthermore, the E1 group had significantly lower harmonics-to-noise-ratio values at the third measurement point compared to the E2 group (P = 0.023). These findings may result from fluid transported to the vocal fold level. The sensations of throat dryness decreased in the E1 (P = 0.001) and E2 groups (P < 0.0005) after the intervention. Perceived phonatory effort decreased statistically significantly at the final measurement point in the E1 (P = 0.002) and E2 (P = 0.031) groups. No variables changed in the control group.

CONCLUSIONS

The waterpipe seems to be efficient in hydrating vocal folds on single use. It seems to be more efficient when employed with a hot water bath, albeit slightly impairing some acoustic values in the short term. Without the heated fluid, it still seems to decrease sensations of throat dryness and affect acoustic voice quality. The waterpipe does not seem to have an effect on phonation threshold pressure, and it seems to lower self-perceived effort just as efficiently whether the waterpipe is employed using a hot water bath or not. Further research is needed to prove the efficacy of long-term usage and usage with voice patients.

Impact of Rehydration Following Systemic Dehydration on Vocal Fold Gene Expression

OBJECTIVE

Biological data on the beneficial effects of vocal fold rehydration are lacking. This study aimed to examine the effects of acute systemic dehydration on vocal fold gene expression and determine whether rehydration would reverse these changes.

METHODS

Male New Zealand White rabbits (N = 24, n = 8/group) provided the animal model. Systemic dehydration was induced by 5 days of water volume restriction. Rehydration was provided by ad-lib water for 3 days following dehydration. Euhydrated rabbits were used as the control group. Vocal fold tissue was dissected. Seventeen genes were selected based on physiological function and role in supporting vocal fold structure, oxidative stress, hemodynamics, and extracellular matrix turnover. Relative gene expression was assessed by RT-qPCR.

RESULTS

Rehydration following systemic dehydration can modulate gene expression, with expression patterns suggesting that rehydration reverses dehydration-induced changes in over half of the tested genes. CLIC5 (chloride intracellular channel 5) and EFEMP1 (EGF containing fibulin extracellular matrix protein 1) genes were significantly upregulated in the dehydration group compared with the euhydrated control. A1BG (alpha-1B-glycoprotein) and IL1RAP (interleukin 1 receptor accessory protein) were downregulated by rehydration compared with the dehydration group.

CONCLUSION

This study provides molecular evidence for a transcriptional response to rehydration following acute systemic dehydration in the vocal folds. These data are the first to study gene expression following realistic dehydration and rehydration paradigms and provide biological data to support clinical recommendations to increase water intake after acute dehydration.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:3499-3505, 2023.

Effects of vocal fold adduction on the particle deposition in the glottis: A numerical analysis and in vitro assessment

BACKGROUND

The efficacy of inhalation therapy depends on the drug deposition in the human respiratory tract. This study investigates the effects of vocal fold adduction on the particle deposition in the glottis.

METHODS

A realistic mouth-throat (MT) geometry was built based on CT images of a healthy adult (MT-A). Mild (MT-B) and great (MT-C) vocal fold (VF) adduction were incorporated in the original model. Monodisperse particles range in size from 3 to 12 μm were simulated at inspiration flow rates of 15, 30 and 45 L per minute (LPM). The regional deposition of drug aerosols was performed in 3D-printed models and quantified using high-performance liquid chromatography.

RESULTS

Both the numerical analysis and in vitro experiments show that most particles are deposited in the mouth, pharynx and supraglottis, while few are deposited in the glottis and subglottis. For most cases in MT-A, the particle quantity in glottis is lower than 0.02 N/mm2 at 15 and 30 LPM while they increase dramatically at 45 LPM. It peaked at 0.347 N/mm2 for 5-μm particles at 45 LPM in MT-B and 2.324 N/mm2 for 6-μm particles at 30 LPM in MT-C. The lowest drug mass faction in the glottis in vitro were found at 15 LPM for MT-A and MT-C, and at 30 LPM for MT-B, whereas it peaked at 45 LPM for all MT models, 0.71% in MT-A, 1.16% in MT-B, and 2.53% in MT-C, respectively.

CONCLUSION

Based on the results of this study, larger particles are more likely to be deposited in the oral cavity, oropharynx, and supraglottis than in the glottis. However, particle deposition in the glottis generally increases with VF adduction and greater inspiratory flow rates.

Nasal Breathing Through a Damp Gauze Enhances Surface Hydration of the Vocal Folds and Optimizes Vocal Function

OBJECTIVE

The present study proposes a direct surface hydration system based on nasal breathing through a damp gauze. The goal is to observe whether such direct hydration procedure positively modifies vocal fold functionality by improving voice quality and enhancing the mobility and pliability of the vocal fold mucosa.

METHODS

Sixty-one young adults without voice problems were enrolled and were randomly divided into three double-blinded treatment groups. In the first group (the gauze group), participants breathed through the nose wrapped in a damp gauze for 10 minutes while doing vocal warm-up exercises to facilitate water penetration into the mucosal layers of the vocal folds. The second group (the exercise group) performed the same warm-up exercises as the gauze group for 10 minutes without hydration procedures. The third group (the control group) talked using their normal speaking voice for 10 minutes. The participants were evaluated before and after the treatment tasks with three tests: a laryngostroboscopic examination (ie, the glottic closure, the amplitude of the mucosal wave, and the maximum opening of the glottic space); voice acoustic analysis (multidimensional voice program); and a perceptual voice evaluation (GRBAS scale).

RESULTS

Results showed that after the use of a damp gauze, glottic closure, the amplitude of the mucosal wave, the maximum opening of the glottic space, the shimmer, and the B of GRBAS all improved.

CONCLUSION

Findings showed significantly better vocal results for the participants of the gauze group, suggesting the damp gauze procedure to be an effective, fast, and economical procedure to improve and optimize vocal fold functionality. It can be hypothesized that the obtained results are related to an improvement in vocal folds surface hydration and viscoelasticity.

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.

An Evaluation of Voice Hygiene in High School Choir Singers

BACKGROUND/OBJECTIVES

Voice hygiene, including proper hydration and limiting phonotraumatic behaviors and refluxogenic foods when appropriate, is essential to voice care for singers. The purpose of this study was to evaluate voice care practices, knowledge, and factors correlating with improved voice hygiene and knowledge in adolescents, an understudied demographic within the singing population.

METHODS

214 high school choir singers, ages 14 through 18, responded to a voice health questionnaire, which included questions about phonotraumatic behaviors and other lifestyle measures regarding voice care, perceived knowledge of the voice, and potential correlational factors such as past singing experience, having a friend or family member when is a professional voice user or possesses an in-depth knowledge of the voice, use of the Internet to sing better or improve understanding of the voice, and other factors. These data were analyzed using descriptive statistics and multivariable linear regressions.

RESULTS

Results showed poor voice hygiene. Phonotraumatic behaviors were frequent and the mean daily water intake was only 5.24 cups. However, 94.4% of the respondents warmed up their voices before rehearsals or performances. The mean total knowledge score, from 0 to 6, was only 2.09. In addition, feeling that one took care of his/her voice well, and use of Internet to sing better or advance knowledge of the voice, were correlated with improved knowledge or measures of voice health.

CONCLUSION

Data suggest that improved instruction regarding voice health in the high school setting is necessary and that the Internet or social media may be valuable resources for reaching adolescent singers.

Reducing Vocal Fatigue While Preserving Realism During Video Game Voice-Overs Using the Vocal Combat Technique: A Randomized Controlled Trial

OBJECTIVE

Vocal Combat Technique (VCT) teaches indirect and direct behavioral voice techniques to voice-over artists performing in violent video games. Although previous work on VCT has shown promise for mitigating dysphonia symptoms, a randomized clinical trial has yet to be undertaken. Therefore, we completed a randomized, controlled trial between a group of experienced video game voice-over actors receiving VCT and a control group comparison.

METHODS

A total of 24 video game voice-over actors completed this study. Participants were randomly assigned to receive VCT or indirect vocal hygiene training prior to completing an intensive 1-hour video game voice recording session. The primary outcome was a change in Voice Handicap Index-10 (VHI-10) preperformance/postperformance. Secondary measures included a modified version of the Evaluation of the Ability to Sing Easily (m-EASE), the Vocal Tract Discomfort Scale (VTDS), and questions regarding return to work. Participants were also rated on the realism of their vocal performance by a blinded video game director.

RESULTS

The VCT group showed a significantly smaller change in VHI-10 and m-EASE scores postperformance, and a higher increased likelihood to return to work compared to the control group. There were no group differences for VTDS or realism ratings. Four participants from the control group exhibited outlier behavior with more pronounced phonotraumatic symptoms following performance than all other participants.

CONCLUSIONS

VCT shows evidence of mitigating symptoms of dysphonia while preserving the realism of the vocal performance. More work is needed to understand performers at risk for more severe vocal symptoms following extreme voice-over work, so as to target them for preventative techniques and voice preservation.

Evidence on Vocal Interventions in Adults: A Scoping Review

OBJECTIVE

To map the evidence on vocal intervention in people over 18 years old.

METHODS

A literature search was conducted using the following electronic databases: Cochrane Library, EMBASE, Latin American and Caribbean Literature on Health Sciences (LILACS), LIVIVO, Pubmed/Medline, Scopus, SpeechBITE, and Web of Science. Gray literature was also used as an information source through searches on Google Scholar, Open Grey, ProQuest Dissertation and Thesis, and the Brazilian digital library of theses and dissertations. Systematic reviews (SR) with a population of individuals over 18 years old were included. The included reviews addressed speech-language pathology interventions in the vocal area with reports of their respective outcome. The methodological quality of the included systematic reviews was analyzed using the AMSTAR II tool. Quantitative analysis was performed by frequency distribution, and qualitative research was analyzed through narrative synthesis.

RESULTS

A total of 2,443 references were retrieved, among which 20 studies met the inclusion criteria. The included studies had critically low quality, lacking the use of population, intervention, comparison, and outcome (PICO) components. Among the included SRs, 40% were made in Brazil, 45% were published in the Journal of Voice, and 75% analyzed dysphonic patients. The most frequent intervention was voice therapy (direct therapy associated with indirect therapy approaches). Positive results were observed in most of the outcomes for all studies.

CONCLUSION

Voice therapy was described as inducing positive effects for voice rehabilitation. However, due to the critically low quality of studies, the literature did not enable us to understand the best results for each intervention. Well-designed studies are necessary to clarify the relationship between the intervention goal and how the intervention was evaluated.

Hydration State and Hyaluronidase Treatment Significantly Affect Porcine Vocal Fold Biomechanics

OBJECTIVES

The understanding of vocal fold hydration state, including dehydrated, euhydrated, rehydrated tissue, and how hydration affects vocal fold biomechanical properties is still evolving. Although clinical observations support the benefits of increasing vocal fold hydration after dehydrating events, more mechanistic information on the effects of vocal fold dehydration and the beneficial effects of rehydration are needed. Alterations to hyaluronic acid (HA), an important component of the vocal fold extracellular matrix, are likely to influence the biomechanical properties of vocal folds. In this study, we investigated the influence of hydration state and HA on vocal fold tissue stiffness via biomechanical testing.

STUDY DESIGN

Prospective, ex vivo study design.

METHODS

Fresh porcine vocal folds (N = 18) were examined following sequential immersion in hypertonic (dehydration) and isotonic solutions (rehydration). In a separate experiment, vocal folds were incubated in hyaluronidase (Hyal) to remove HA. Control tissues were not exposed to any challenges. A custom micromechanical system with a microforce sensing probe was used to measure the force-displacement response. Optical strain was calculated, and ultrasound imaging was used to measure tissue cross-sectional area to obtain stress-strain curves.

RESULTS

Significant increases (P ≤ 0.05) were found in tangent moduli between dehydrated and rehydrated vocal folds at strains of ε = 0.15. The tangent moduli of Hyal-digested tissues significantly increased at both ε = 0.15 and 0.3 (P ≤ 0.05).

CONCLUSION

Vocal fold dehydration increased tissue stiffness and rehydration reduced the stiffness. Loss of HA increased vocal fold stiffness, suggesting a potential mechanical role for HA in euhydrated vocal folds.

Cough desensitization treatment for patients with refractory chronic cough: results of a second pilot randomized control trial

OBJECTIVE

The purpose of this study was to collect pilot efficacy data on a novel treatment for refractory chronic cough (RCC), which we call cough desensitization treatment (CDT).

DESIGN AND METHODS

In this parallel cohort, sham-controlled, randomized controlled trial, 21 adults with RCC were randomly assigned to 12 sessions of either CDT (progressive doses of aerosolized capsaicin while behaviorally suppressing cough; n = 11) or a sham treatment (repeated exposure to aerosolized saline; n = 9). The Leicester Cough Questionnaire (LCQ) was the primary outcome measure. Perceived cough severity with a visual analogue scale and cough challenge testing (for measuring cough-reflex sensitivity) were secondary outcome measures. Data were analyzed with mixed effects linear regression and follow-up contrasts.

RESULTS

Results on all measures favored CDT. Excluding one sham participant, whose baseline LCQ scores were deemed unreliable, mean change in LCQ at 3-weeks post treatment was 6.35 and 2.17 in the CDT and sham groups, respectively. There was moderate to strong evidence of a greater improvement in the CDT group in total LCQ score (p = .058) and LCQ Psychological domain (p = .026) and Physical domain (p = .045) scores. Strong evidence was found for a greater reduction in urge-to-cough during CCT in the CDT group (p = .037) and marginal for a reduction in the capsaicin cough-reflex sensitivity (p = .094). There was weak evidence of a greater reduction in cough severity in the CDT group (p = .103).

DISCUSSION

Although the study is limited due to the small sample size, the data provide additional evidence supporting further research on CDT. CDT resulted in a greater change in the primary efficacy measure (LCQ) than both pharmaceutical and behavioral treatments currently found in the literature.

TRIAL REGISTRATION

This trial (NCT05226299) was registered on Clinicaltrials.gov on 07/02/2022.

Independence of Vocal Load From Vocal Pathology Across Singing Genres

OBJECTIVE

To investigate the extent to which vocal load is associated with previous diagnosis of a vocal pathology among four major genres of singers (primarily classical, primarily musical theatre (MT), classical and MT combined, and contemporary commercial music only).

STUDY DESIGN

Cross sectional survey.

METHODS/DESIGN

An anonymous online survey was sent out to about 1000 professional singers through convenience sampling to touring companies, opera companies, MT companies, agents, directors and musical directors. Social media and email were used to solicit participation in the study. We utilized means and standard deviations for continuous characteristics and frequencies and percentages for categorical characteristics and calculated P values to assess whether differences were statistically significant.

RESULTS

A total of 396 professional singers completed the survey, yielding a 40% response rate. Nonprofessional singers, incomplete surveys, and respondents <18 years old were excluded, resulting in a total of 238 responses. Among the 238 participants, 32% were performing in the classical style primarily, 33% in the MTstyle primarily, 15% in both classical and MT, and 20% in other contemporary styles only. Mean age was highest among CV + MT and lowest among primarily MT. Combined classical/MT singers were most likely to have a career outside of vocal performance and continue to work in that career followed by other contemporary styles, classical and MT (P = 0.02). Participants in the combined classical/MT group were most likely to have a reported history of vocal pathology followed by classical, other contemporary styles and MT (not statistically significant). However, participants in the contemporary styles were most likely to have a history of more than one type of vocal pathology. Mean vocal load was highest for the MT group. Other nonsinging factors proved significant such as allergy, hydration and acid reflux. Symptoms of allergies were found to be significant across singing genres. A possible reverse causality association was identified in regards to water intake. Participants with acid reflux were three times more likely to have ever reported vocal pathology.

CONCLUSION

Vocal load was not significantly associated with vocal pathology across singing genres; however other nonsinging factors such as allergy, reflux and water intake were significantly associated with vocal pathology.

Acoustic Voice and Speech Biomarkers of Treatment Status during Hospitalization for Acute Decompensated Heart Failure

This study investigates acoustic voice and speech features as biomarkers for acute decompensated heart failure (ADHF), a serious escalation of heart failure symptoms including breathlessness and fatigue. ADHF-related systemic fluid accumulation in the lungs and laryngeal tissues is hypothesized to affect phonation and respiration for speech. A set of daily spoken recordings from 52 patients undergoing inpatient ADHF treatment was analyzed to identify voice and speech biomarkers for ADHF and to examine the trajectory of biomarkers during treatment. Results indicated that speakers produce more stable phonation, a more creaky voice, faster speech rates, and longer phrases after ADHF treatment compared to their pre-treatment voices. This project builds on work to develop a method of monitoring ADHF using speech biomarkers and presents a more detailed understanding of relevant voice and speech features.

Effects of Virtual Teaching on Swedish Teachers' Voices During the COVID-19 Pandemic

PURPOSE

Since the beginning of 2020, teachers all over the world have had to switch over to virtual teaching because of the COVID-19 pandemic. This change of teaching mode has unknown consequences on the vocal health of teachers who already experience voice disorders at a rate nearly double that of the general population. Therefore, the purpose of this study is to investigate teachers' self-reported voice problems during virtual teaching compared to face-to-face teaching and how they are associated to perceived risk factors in the work environment.

METHOD

Participants included 141 teachers (49 males, 92 females) in high schools and higher education in Sweden who responded to an internet-based survey. Information was collected about participants' self-reported voice handicap using a translated version of the Voice Handicap Index-10 (VHI-10). Information about self-reported VTD (Vocal Tract Discomfort) symptoms and dysphonia was collected in regard to both modes of teaching (virtual vs face-to- face). The survey also included questions on risk factors related to vocal health.

RESULTS

Self-reported voice handicap and VTD symptoms were slightly lower during periods of virtual teaching compared to periods of face-to-face teaching. There was a lower frequency of dysphonia symptoms during virtual teaching compared to face-to- face teaching, however the difference was not statistically significant. In addition, 34% of teachers reported experiencing more voice problems when teaching face-to-face while 15% reported more voice problems when teaching virtually. The most reported VTD symptoms during both virtual and face-to-face teaching were having a dry and a tight throat. The dysphonia symptoms with the highest reported frequency were a tense voice and hoarseness in both modes of teaching. Risk factors associated with higher prevalence of voice symptoms and/or higher levels of voice handicap during virtual teaching were air quality and straining the voice while teaching face-to-face. In addition, those teachers who reported more voice problems while teaching virtually also reported feeling more stressed.

CONCLUSION

The results showed a slight decrease in voice symptoms and voice handicap during virtual teaching compared to face-to-face teaching. Although multifactorial, results suggest that a potential positive effect may be attributed to better air quality in the work environment and more favorable acoustic conditions preventing teachers from straining their voice.

Synthetic mucus for an ex vivo phonation setup: Creation, application, and effect on excised porcine larynges

Laryngeal mucus hydrates and lubricates the deformable tissue of the vocal folds and acts as a boundary layer with the airflow from the lungs. However, the effects of the mucus' viscoelasticity on phonation remain widely unknown and mucus has not yet been established in experimental procedures of voice research. In this study, four synthetic mucus samples were created on the basis of xanthan with focus on physiological frequency-dependent viscoelastic properties, which cover viscosities and elasticities over 2 orders of magnitude. An established ex vivo experimental setup was expanded by a reproducible and controllable application method of synthetic mucus. The application method and the suitability of the synthetic mucus samples were successfully verified by fluorescence evidence on the vocal folds even after oscillation experiments. Subsequently, the impact of mucus viscoelasticity on the oscillatory dynamics of the vocal folds, the subglottal pressure, and acoustic signal was investigated with 24 porcine larynges (2304 datasets). Despite the large differences of viscoelasticity, the phonatory characteristics remained stable with only minor statistically significant differences. Overall, this study increased the level of realism in the experimental setup for replication of the phonatory process enabling further research on pathological mucus and exploration of therapeutic options.

Proteomic analysis reveals that aging rabbit vocal folds are more vulnerable to changes caused by systemic dehydration

BACKGROUND

Older adults are more prone to develop systemic dehydration. Systemic dehydration has implications for vocal fold biology by affecting gene and protein expression. The objective of this study was to quantify vocal fold protein changes between two age groups and hydration status, and to investigate the interaction of age and hydration status on protein expression, which has not been investigated in the context of vocal folds before. Comparative proteomics was used to analyze the vocal fold proteome of 6.5-month-old and > 3-year-old rabbits subjected to water ad libitum or water volume restriction protocol.

RESULTS

Young and older adult rabbits (n = 22) were either euhydrated (water ad libitum) or dehydrated by water volume restriction. Dehydration was confirmed by body weight loss of - 5.4% and - 4.6% in young and older groups, respectively, and a 1.7-fold increase of kidney renin gene expression in the young rabbits. LC-MS/MS identified 2286 proteins in the rabbit vocal folds of young and older adult rabbits combined. Of these, 177, 169, and 81 proteins were significantly (p ≤ 0.05) affected by age, hydration status, or the interaction of both factors, respectively. Analysis of the interaction effect revealed 32 proteins with opposite change patterns after dehydration between older and young rabbit vocal folds, while 31 proteins were differentially regulated only in the older adult rabbits and ten only in the young rabbits in response to systemic dehydration. The magnitude of changes for either up or downregulated proteins was higher in the older rabbits. These proteins are predominantly related to structural components of the extracellular matrix and muscle layer, suggesting a disturbance in the viscoelastic properties of aging vocal fold tissue, especially when subjected to systemic dehydration.

CONCLUSIONS

Water restriction is a laboratory protocol to assess systemic dehydration-related changes in the vocal fold tissue that is translatable to human subjects. Our findings showed a higher number of proteins differentially regulated with a greater magnitude of change in the vocal folds of older adult rabbits in the presence of systemic dehydration compared to younger rabbits. The association of these proteins with vocal fold structure and biomechanical properties suggests that older human subjects may be more vulnerable to the effects of systemic dehydration on vocal function. The clinical implications of these protein changes warrant more investigation, but age should be taken into consideration when evaluating vocal treatment recommendations that interfere with body fluid balance.

Voice Problems Among School Teachers employing the Tele-teaching Modality

OBJECTIVES

To assess the prevalence of voice problems among teachers in Riyadh during tele-teaching and examine the relationship between the Voice Handicap Index 10 (VHI10) scores and a variety of risk factors believed to be related to voice problems. We also assessed awareness of voice hygiene and therapy among teachers.

STUDY DESIGN

An observational cross-sectional study conducted using a multistage random sampling method among Riyadh school teachers who taught by tele-teaching for a minimum of one year.

METHODS

A self-assessment questionnaire which included demographic information about teachers, factors related to their teaching backgrounds, tele-teaching settings, effects of tele-teaching on the voice, medical and social histories, reports of voice and reflux symptoms, VHI10, and general knowledge about voice hygiene. This was distributed to school teachers using an SMS link through the Ministry of Education's IT department.

RESULTS

A total 495 were included in the study after exclusions. The prevalence of teachers who had significant voice problems during tele-teaching (VHI10>11) was 21.6%. Multiple risk factors significantly increased the risk of voice problems during tele-teaching. These factors included being female, teacher age, the presence of background noise from both teachers and students, loud voices, using an open camera during the teaching, stress and anxiety, allergies, respiratory disease, reflux, hearing problems, and a family history of voice problems. Only 4.6% of respondents were familiar with voice hygiene and voice therapy, but 65% believe that it is important for teachers to be knowledgeable about them.

CONCLUSIONS

Due to the lower prevalence of voice disorders among tele-teaching compared to traditional teaching methods, tele-teaching may be a viable option for teachers who have voice problems. There are still several factors influencing voice problems among tele-teachers. To attenuate potential risks, it is crucial that teachers are aware of the concepts of voice hygiene and voice therapy.

Deep learning and machine learning-based voice analysis for the detection of COVID-19: A proposal and comparison of architectures

Alongside the currently used nasal swab testing, the COVID-19 pandemic situation would gain noticeable advantages from low-cost tests that are available at any-time, anywhere, at a large-scale, and with real time answers. A novel approach for COVID-19 assessment is adopted here, discriminating negative subjects versus positive or recovered subjects. The scope is to identify potential discriminating features, highlight mid and short-term effects of COVID on the voice and compare two custom algorithms. A pool of 310 subjects took part in the study; recordings were collected in a low-noise, controlled setting employing three different vocal tasks. Binary classifications followed, using two different custom algorithms. The first was based on the coupling of boosting and bagging, with an AdaBoost classifier using Random Forest learners. A feature selection process was employed for the training, identifying a subset of features acting as clinically relevant biomarkers. The other approach was centered on two custom CNN architectures applied to mel-Spectrograms, with a custom knowledge-based data augmentation. Performances, evaluated on an independent test set, were comparable: Adaboost and CNN differentiated COVID-19 positive from negative with accuracies of 100% and 95% respectively, and recovered from negative individuals with accuracies of 86.1% and 75% respectively. This study highlights the possibility to identify COVID-19 positive subjects, foreseeing a tool for on-site screening, while also considering recovered subjects and the effects of COVID-19 on the voice. The two proposed novel architectures allow for the identification of biomarkers and demonstrate the ongoing relevance of traditional ML versus deep learning in speech analysis.

COVID-19 symptoms are reduced by targeted hydration of the nose, larynx and trachea

Dehydration of the upper airways increases risks of respiratory diseases from COVID-19 to asthma and COPD. We find in human volunteer studies involving 464 human subjects in Germany, the US, and India that respiratory droplet generation increases by up to 4 orders of magnitude in dehydration-associated states of advanced age (n = 357), elevated BMI-age (n = 148), strenuous exercise (n = 20) and SARS-CoV-2 infection (n = 87), and falls with hydration of the nose, larynx and trachea by calcium-rich hypertonic salts. We also find in a protocol of exercise-induced airway dehydration that hydration of the airways by calcium-rich salts increases oxygenation relative to a non-treatment control (P < 0.05). In a random control study of COVID-19 positive subjects (n = 40), thrice-a-day delivery of the calcium-rich hypertonic salts (active) suppressed respiratory droplet generation by 51% ± 11% and increased oxygen saturation over three days of treatment by 48.08% ± 9.61% (P < 0.001), while no changes were observed in the nasal-saline control group. Self-reported symptoms significantly declined in the active group and did not decline in the control group. Hydration of the upper airways appears promising as a non-drug approach for reducing risks of respiratory diseases such as COVID-19.

Recurring exposure to low humidity induces transcriptional and protein level changes in the vocal folds of rabbits

Voice disorders are an important human health condition. Hydration is a commonly recommended preventive measure for voice disorders though it is unclear how vocal fold dehydration is harmful at the cellular level. Airway surface dehydration can result from exposure to low humidity air. Here we have induced airway surface dehydration in New Zealand White rabbits exposed to a recurring 8-h low humidity environment over 15 days. This model mimics an occupational exposure to a low humidity environment. Exposure to moderate humidity was the control condition. Full thickness soft-tissue samples, including the vocal folds and surrounding laryngeal tissue, were collected for molecular analysis. RT-qPCR demonstrated a significant upregulation of MUC4 (mucin 4) and SCL26A9 (chloride channel) and a large fold-change though statistically non-significant upregulation of SCNNA1 (epithelial sodium channel). Proteomic analysis demonstrated differential regulation of proteins clustering into prospective functional groups of muscle structure and function, oxidative stress response, and protein chaperonin stress response. Together, the data demonstrate that recurring exposure to low humidity is sufficient to induce both transcriptional and translational level changes in laryngeal tissue and suggest that low humidity exposure induces cellular stress at the level of the vocal folds.

Effect of sex hormones on human voice physiology: from childhood to senescence

The aim of the present literature review is to describe the influence of sex hormones on the human voice in physiological conditions. As a secondary sexual organ, the larynx is affected by sex hormones and may change considerably over the lifespan. In the current review, sex hormone-related voice modifications occurring during childhood, puberty, the menstrual cycle, pregnancy and senescence are described. The roles of sex hormones (including gonadotropins, testosterone, estrogen, androstenedione, dehydroepiandrosterone, and dehydroepiandrosterone-sulfate) underlying physiological voice changes are discussed, the main differences between males and females are explained and clinical implications are taken into account.

Analysis of the singing voice handicap index for elderly choristers

PURPOSE

To analyze the singing voice handicap index in elderly choristers and verify its relationship with the profile, habits and health conditions of the participants.

METHODS

110 individuals aged 60 years or older, participating in amateur choirs, were included. Choir singers were interviewed in order to verify data such as age, time in choir singing, vocal classification, and the presence of habits and health conditions adverse to voice production. Subsequently, they answered the questionnaire "Singing Voice Handicap Index (SVHI)", which assesses the individual's self-perception in relation to experiences in the use of the singing voice.

RESULTS

The SVHI score had a median of 25, with a minimum score of 0 and a maximum score of 86. The most scored items were related to physical aspects in the use of singing voice: "I am unable to use my 'high voice'" (Q10) and "My throat is dry when I sing"(Q13). It was found that older adults over 75 years of age had a greater voice handicap when compared to younger ones (p=0.020). Choir singers classified as contralto also had a higher SVHI score (p=0.023), as well as individuals who reported drinking little water (p=0.007).

CONCLUSION

The choristers in this study presented a singing voice handicap index compatible with healthy singing voices. When verifying the relationship of the SVHI score with the characteristics of the participants and with respect to habits and health conditions, it was found that the elderly choir singers over 75 years old, the contralto choir singers, and those who claimed to drink little water had higher scores for the singing voice handicap.

Immediate effect of surface laryngeal hydration associated with tongue trill technique in amateur singers

PURPOSE

To analyze the immediate effect of laryngeal surface hydration associated with the performance of Tongue Trills (TT) on singers.

METHODS

Thirty singers without vocal complaints or laryngeal alterations divided into control (CG) and experimental (EG) groups. The CG performed the TT for five minutes. The EG was submitted a nebulization with 3 ml of saline solution followed by TT for five minutes. Voice self-assessment, acoustic analysis and perceptual assessment were performed at Pre (Pre TT) and post (PTT) moments in CG and pre (Pre TT), post hydration (PH) and post hydration + TT (PHTT) in GE. In the self-assessment were evaluated quality, stability, vocal intensity and hoarseness. There were extract the values of the Fundamental frequency; Jitter%; Shimmer%, Noise-to-harmonic Ratio e Cepstral Peak Prominence-Smoothed (CPPs) in the acoustic analyze. The perceptual evaluation was performed by an experienced speech therapist.

RESULTS

Comparing the results of self-assessment between groups showed improvement in the perception of stability and vocal intensity in the PTT (CG) in relation to PH (EG). Comparison between the EG moments showed a statistical difference in the vocal intensity perception, indicating a better results for PHTT. There was no statistical difference between the groups investigated in the perceptual assessments and acoustic analysis.

CONCLUSION

Surface laryngeal hydration does not potentiate the effect of TT on naturally hydrated singers with 3ml nebulization. For voice professionals with high vocal demand, surface hydration can be introduced during voice use to maintain vocal quality.

The Effects of Caffeine on Voice: A Systematic Review

BACKGROUND

Caffeine is considered a dehydrating agent due to its diuretic effects and influences the body's fluid balance. The relationship between voice and hydration has been widely investigated and it is accepted that inadequate hydration has detrimental effects on phonation. Since dehydration negatively affects the vocal folds and caffeine is considered a dehydrating agent, it can be hypothesized that voice might be negatively affected by caffeine intake. This systematic review aims to summarize and appraise the available evidence regarding the effects of caffeine on voice.

METHODS

Randomized and non-randomized experimental studies of healthy participants were retrieved following an electronic searching of six databases in June 2020. No publication, language or date restrictions were applied. Data extraction of relevant data and risk of bias assessment was conducted independently by two reviewers.

RESULTS

Five non-randomized experimental studies were deemed eligible for inclusion. The format of the administered interventions in the included studies was either liquid (coffee) or solid (caffeine tablets). Reported outcome measures used to examine the effects of caffeine on phonation consisted of acoustic, aerodynamic and (auditory & self-) perceptual. No measures were adversely affected by caffeine consumption.

CONCLUSION

Clinicians commonly advise patients to refrain from caffeine, as caffeine intake increases diuresis with subsequent effects on fluid balance. Such imbalances can potentially induce dehydration which can be detrimental to phonation. This notion cannot be supported empirically, as the evidence is deemed unreliable and no firm conclusions can be elicited to guide clinical practice. The results of this review demonstrate the lack of research in the field and the necessity for future investigations in order to inform evidence-based practice through reliable and valid outcomes.

Health, work performance, and risk of infection in office-like environments: The role of indoor temperature, air humidity, and ventilation

Epidemiological and experimental studies have revealed the effects of the room temperature, indoor air humidity, and ventilation on human health, work and cognitive performance, and risk of infection. In this overview, we integrate the influence of these important microclimatic parameters and assess their influence in offices based on literature searches. The dose-effect curves of the temperature describe a concave shape. Low temperature increases the risk of cardiovascular and respiratory diseases and elevated temperature increases the risk of acute non-specific symptoms, e.g., dry eyes, and respiratory symptoms. Cognitive and work performance is optimal between 22 °C and 24 °C for regions with temperate or cold climate, but both higher and lower temperatures may deteriorate the performances and learning efficiency. Low temperature may favor virus viability, however, depending on the status of the physiological tissue in the airways. Low indoor air humidity causes vulnerable eyes and airways from desiccation and less efficient mucociliary clearance. This causes elevation of the most common mucous membrane-related symptoms, like dry and tired eyes, which deteriorates the work performance. Epidemiological, experimental, and clinical studies support that intervention of dry indoor air conditions by humidification alleviates symptoms of dry eyes and airways, fatigue symptoms, less complaints about perceived dry air, and less compromised work performance. Intervention of dry air conditions by elevation of the indoor air humidity may be a non-pharmaceutical treatment of the risk of infection by reduced viability and transport of influenza virus. Relative humidity between 40 and 60% appears optimal for health, work performance, and lower risk of infection. Ventilation can reduce both acute and chronic health outcomes and improve work performance, because the exposure is reduced by the dilution of the indoor air pollutants (including pathogens, e.g., as virus droplets), and in addition to general emission source control strategies. Personal control of ventilation appears an important factor that influences the satisfaction of the thermal comfort due to its physical and positive psychological impact. However, natural ventilation or mechanical ventilation can become sources of air pollutants, allergens, and pathogens of outdoor or indoor origin and cause an increase in exposure. The "health-based ventilation rate" in a building should meet WHO's air quality guidelines and dilute human bio-effluent emissions to reach an acceptable perceived indoor air quality. Ventilation is a modifying factor that should be integrated with both the indoor air humidity and the room temperature in a strategic joint control to satisfy the perceived indoor air quality, health, working performance, and minimize the risk of infection.

Vocal tract discomfort and voice handicap index in patients undergoing thyroidectomy

PURPOSE

This study aims to investigate the frequency and severity of vocal tract discomfort (VTD) symptoms and to determine the relationship between VTD and type of thyroidectomy, voice problem history, vocal abuse, and misuse behaviors, and the voice handicap index (VHI) in the thyroidectomy patients undergoing thyroidectomy, pre- and post-operatively pre- and post-thyroidectomy.

MATERIALS

The sample comprised 21 thyroidectomy patients undergoing thyroidectomy, including 10 patients with total thyroidectomy and 11 patients with partial thyroidectomy. The participants underwent videolaryngoscopy examination and completed the voice history questionnaire, the VTD scale, and the VHI, before and after the surgery.

RESULTS

Dryness was the most frequently occurring symptom, pre- and post-thyroidectomy. Participants with total thyroidectomy reported significantly higher frequency and severity of tickling than those in the preoperative status (p<.05). The frequency and severity of many VTD symptoms in the participants with voice problems and a vocal abuse and misuse history were higher than those without such a history at both assessment times (p<.05). There was significant correlation between the frequency and severity of VTD and VHI scores, pre-thyroidectomy pre-operatively (r = 0.488-0.575, p<.05).

CONCLUSIONS

An increment in the frequency and severity of tickling was reported by total thyroidectomy patients, post-thyroidectomy post-operatively. The type of thyroidectomy, voice problem history, and vocal abuse and misuse behaviors seem to influence the frequency and severity of VTD. Considering the correlation between VTD and VHI, the VTD scale provides important clinical information and can be used for evaluation and consultation purposes.

RNA sequencing identifies transcriptional changes in the rabbit larynx in response to low humidity challenge

BACKGROUND

Voice disorders are a worldwide problem impacting human health, particularly for occupational voice users. Avoidance of surface dehydration is commonly prescribed as a protective factor against the development of dysphonia. The available literature inconclusively supports this practice and a biological mechanism for how surface dehydration of the laryngeal tissue affects voice has not been described. In this study, we used an in vivo male New Zealand white rabbit model to elucidate biological changes based on gene expression within the vocal folds from surface dehydration. Surface dehydration was induced by exposure to low humidity air (18.6% + 4.3%) for 8 h. Exposure to moderate humidity (43.0% + 4.3%) served as the control condition. Ilumina-based RNA sequencing was performed and used for transcriptome analysis with validation by RT-qPCR.

RESULTS

There were 103 statistically significant differentially expressed genes identified through Cuffdiff with 61 genes meeting significance by both false discovery rate and fold change. Functional annotation enrichment and predicted protein interaction mapping showed enrichment of various loci, including cellular stress and inflammatory response, ciliary function, and keratinocyte development. Eight genes were selected for RT-qPCR validation. Matrix metalloproteinase 12 (MMP12) and macrophage cationic peptide 1 (MCP1) were significantly upregulated and an epithelial chloride channel protein (ECCP) was significantly downregulated after surface dehydration by RNA-Seq and RT-qPCR. Suprabasin (SPBN) and zinc activated cationic channel (ZACN) were marginally, but non-significantly down- and upregulated as evidenced by RT-qPCR, respectively.

CONCLUSIONS

The data together support the notion that surface dehydration induces physiological changes in the vocal folds and justifies targeted analysis to further explore the underlying biology of compensatory fluid/ion flux and inflammatory mediators in response to airway surface dehydration.

Muscle Tension Dysphagia: Contributing Factors and Treatment Efficacy

OBJECTIVE

To determine factors contributing to disease etiology and treatment efficacy.

STUDY DESIGN

Original Report.

SETTING

Tertiary academic center.

METHODS

IRB approved prospective study of 20 patients with reported dysphagia who exhibited normal oropharyngeal and esophageal swallowing function as evidenced by videofluoroscopic swallow study, esophagogastroduodenoscopy, high-resolution esophageal manometry with stationary impedance, and Bravo pH probe off proton pump inhibitor. Patients underwent speech-language pathology intervention.

RESULTS

Atypical laryngeal muscle tension was present in 100% of patients. Forty percent of patients had diagnosed positive gastroesophageal reflux disease. Sixty-five percent of patients showed signs of non-specific laryngeal inflammation and laryngeal hyperresponsiveness during strobolaryngoscopy. All patients reported a mean of 90% recovery by the completion of voice therapy directed toward unloading muscle tension.

CONCLUSION

The study results suggest an association between laryngeal muscle tension and these patients' dysphagia symptoms regardless of associated conditions. Speech-language pathology intervention showed high treatment efficacy.

LEVEL OF EVIDENCE

2c- Outcomes research.

Dysphonia and Vocal Tract Discomfort While Working From Home During COVID-19

Objective

During COVID-19, government measures to prevent disease spread included advice to work from home. In addition to occupational risk factors, the increased use of telecommunication and changed work environment may contribute to voice and vocal tract discomfort (VTD). This study established the prevalence, incidence, characteristics and impact of self-perceived dysphonia and VTD in those working from home during COVID-19.

Methods

A cross-sectional, observational study using an online survey recruited 1575 participants. It captured information about dysphonia and VTD presence, onset, and severity. Those with dysphonia completed the voice-related quality of life to measure impact. Regression analyses identified risk factors for voice and vocal tract problems.

Results

Dysphonia and VTD prevalence rates were 33% and 68%, respectively, incidences were 28% and 50%. Perceived dysphonia severity was mild in 72% of cases. Dry throat was the most common VTD symptom at 66%. Mean voice-related quality of life score was 82.4 (standard deviation ± 13.2). Raising or straining the voice while working predicted new onset dysphonia and VTD. Increasing telecommunication use was associated with worse dysphonia and VTD onset.

Conclusion

Those working from home have seen a rise in dysphonia and VTD, which were associated with communication modality and change in environment. If home offices become the ‘new normal’ post-COVID, workplaces should consider voice training for employees to limit potential difficulties.

Unraveling the molecular pathobiology of vocal fold systemic dehydration using an in vivo rabbit model

Vocal folds are a viscoelastic multilayered structure responsible for voice production. Vocal fold epithelial damage may weaken the protection of deeper layers of lamina propria and thyroarytenoid muscle and impair voice production. Systemic dehydration can adversely affect vocal function by creating suboptimal biomechanical conditions for vocal fold vibration. However, the molecular pathobiology of systemically dehydrated vocal folds is poorly understood. We used an in vivo rabbit model to investigate the complete gene expression profile of systemically dehydrated vocal folds. The RNA-Seq based transcriptome revealed 203 differentially expressed (DE) vocal fold genes due to systemic dehydration. Interestingly, function enrichment analysis showed downregulation of genes involved in cell adhesion, cell junction, inflammation, and upregulation of genes involved in cell proliferation. RT-qPCR validation was performed for a subset of DE genes and confirmed the downregulation of DSG1, CDH3, NECTIN1, SDC1, S100A9, SPINK5, ECM1, IL1A, and IL36A genes. In addition, the upregulation of the transcription factor NR4A3 gene involved in epithelial cell proliferation was validated. Taken together, these results suggest an alteration of the vocal fold epithelial barrier independent of inflammation, which could indicate a disruption and remodeling of the epithelial barrier integrity. This transcriptome provides a first global picture of the molecular changes in vocal fold tissue in response to systemic dehydration. The alterations observed at the transcriptional level help to understand the pathobiology of dehydration in voice function and highlight the benefits of hydration in voice therapy.

Voice-related complaints and vocal and nonvocal habits of Hindustani classical singers: a questionnaire-based study

OBJECTIVE

This study aimed to profile voice-related complaints, as well as vocal and nonvocal habits among Hindustani classical singers.

METHOD

Cross-sectional study design was used to profile voice-related complaints and vocal and nonvocal habits among Hindustani classical singers. Phase I involved developing a questionnaire for exploring vocal and nonvocal habits. Phase II involved the administration of the survey to 61 Hindustani classical singers.

RESULTS

Based on the overall findings, 41% of singers reported of at least three vocal symptoms. The most common vocal symptoms included out of breath while singing, felling tired after singing and experiencing tension or tightness in neck/shoulder. The commonly reported vocal habits included excessive phone use, loud coughing/sneezing, throat clearing and excessive speaking. A high consumption of caffeinated beverages and spicy food were also reported.

CONCLUSION

This study helps to highlight the voice-related complaints and vocal and nonvocal habits of Hindustani classical singers. Further studies, need to explore the prevalence of voice problems incorporating other dimensions of voice evaluation such as acoustic, auditory perceptual, self-reported and laryngeal examination.

Substitution Voice Rehabilitation After Open Partial Horizontal Laryngectomy Through the Proprioceptive Elastic Method (PROEL): A Preliminary Study

OBJECTIVE

The aim was to investigate the efficacy of the Proprioceptive Elastic Method (PROEL) in the rehabilitation of the substitution voice after open partial horizontal laryngectomy (OPHL).

STUDY DESIGN

Prospective outcome study.

METHODS

Fifteen patients surgically treated by OPHL type II or type III for laryngeal cancer were recruited (experimental group). Each patient underwent a specific program of voice rehabilitation based on the PROEL method with the same speech and language pathologist. Acoustic-aerodynamic analysis: maximum phonation time (MPT); spectrographic classification (Titze's modified classification), perceptual analysis (INFVo rating scale) and self-assessments (SECEL questionnaire) were performed before the treatment (T0), after 3 months of rehabilitation (T1), and at the end of the 6-month rehabilitation program (T2). A control sample of other 15 patients who underwent OPHL type II or type III and who underwent a standard perioperative rehabilitation was randomly extracted from an historical database and compared to the experimental group.

RESULTS

Significative voice improvements between T0-T1 and T2 were found for acoustic, aerodynamic, perceptual, and self-assessments analysis in the experimental group. Significative differences were found between the experimental group at T2 and the control sample for aerodynamic, self-assessment, and perceptual analysis.

CONCLUSIONS

The results of the present study support PROEL method as an effective approach for substitution voice rehabilitation after OPHL type II and III. Randomized controlled trials on larger groups of patients are needed in future in order to compare PROEL with other rehabilitative approaches.

Comparison of Reported Vocal Habits of First-Year Undergraduate and Graduate Vocal Performance Majors

OBJECTIVE

Vocal performance students at the collegiate level are faced with rigorous training protocols for which they are required to maintain optimal vocal quality and function. The purpose of this study was to compare the vocal habits and hygiene practices of incoming undergraduate Bachelor of Music (BM), Master of Music (MM), Doctor of Musical Arts (DMA), and Artist Diploma (AD) vocal performance students at a tier I music conservatory. To date, no study has compared the reported vocal habits of undergraduate and graduate vocal performance students within the same music conservatory.

METHODS

Two-hundred and eighty six incoming vocal performance majors including undergraduate (n = 79), graduate master's candidates (n = 171), and graduate doctoral/AD candidates (n = 36) at the University of Cincinnati College-Conservatory of Music over a period of 9 years (2008-2017) completed a questionnaire designed to gain information about their baseline vocal patterns and hygiene practices. The intake form included questions about daily liquid intake, past voice treatment, current adverse voice symptoms, warm-up and cool-down use, average time spent singing daily, and any harmful voice hygiene practices such as phonotraumatic behaviors (ie, yelling, frequent throat clearing). This data was retrospectively analyzed for significant findings within groups and between groups.

RESULTS/CONCLUSIONS

Results from the questionnaires detailing the undergraduate voice performance participants' self-reported current and past vocal symptoms, current vocal health and hygiene practices, reported voice training habits, and other pertinent factors that may lead to potential voice problems in comparison to those same factors presented in the graduate master's and doctoral/artist diploma voice performance participants' questionnaires are provided. Data gained from the voice performance participants revealed that the potential for voice-related problems exists within all groups, as 45.5% of undergraduate students, 38.6% of graduate master's students, and 44.4% of graduate doctoral/artist diploma students stated at least one current voice issue or adverse symptom. The findings indicate that there is no significant difference regarding level of education in relation to percentage of subjects that reported at least one current adverse vocal symptom, current voice problem, and/or reported negative hygiene practice. The information provided in this study may be beneficial for those who are vocal performers as well as those involved in the training of collegiate-level vocal performance students.

Vocal Hygiene in Collegiate Singers-Does Formal Training Relate to Practices?

BACKGROUND

Vocal hygiene is vitally important for protecting vocal quality and promoting vocal longevity. It includes adequate hydration, avoidance of environmental irritants, and refraining from phonotraumatic behaviors such as screaming, excessive talking, and throat clearing. Formal singing training in addition to enhancing singing techniques, is also assumed to promote good vocal hygiene. Consequently, we investigated whether collegiate singers with formal training are more likely to practice good vocal hygiene habits than untrained collegiate singers.

METHODS

We completed a prospective cohort study, where collegiate singers at Stanford University were voluntarily enrolled in an annual vocal health clinic. Full laryngeal exams were performed and demographic information, formal vocal training status, and information on vocal hygiene habits were obtained through questionnaires. The results were then analyzed by grouping singers as "untrained" if less than 1 year of formal training, and "trained" if greater than a year.

RESULTS

A total of 82 singers were included for analysis, with 49 (59.8%) having greater than one year of formal training. Trained singers were more likely to employ a primary musical singing style of classical or operatic singing compared to untrained singers who were more likely to utilize "R&B" (P < 0.001). No significant differences were found between groups for hydration practices (P = 0.20), caffeine consumption (P = 0.73), warm up practices (P = 0.08), and phonotraumatic behaviors. Alcohol consumption, smoking tobacco, marijuana, e-cigarette usage was similar between groups. Overall, 11% of our sample reported intermittent less than daily marijuana use, with one singer reporting daily consumption. None of the singers in this sample used e-cigarettes. These rates are noticeably lower than the agematched United States population. Perceptions of cigarettes, marijuana, electronic cigarettes, alcohol, and caffeine were also the same between groups, with the vast majority of singers perceiving these agents as harmful to the voice (64%-100% depending on the agent). No laryngeal pathology was identified during laryngeal examination of any singers.

CONCLUSIONS

Vocal hygiene habits are similar between trained and untrained collegiate singers. This likely relates to a desire for vocal longevity irrespective of prior training. This may dispel the long-held assumption that formal training was necessary to develop good vocal habits. We do however, present a very homogenous, highly educated sample of collegiate singers from Stanford University, having significantly less at-risk behavior than their aged-matched counterparts in the general US population. A lack of laryngeal pathology despite extensive vocal demands may also be reflective of good vocal hygiene habits.