Vocal dose measures: quantifying accumulated vibration exposure in vocal fold tissues

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Vocal Fold Vibratory Dose and Perceived Exertion Responses to the Fluid Interval Test for Voice (FIT-V): A Novel Vocal Loading Task Platform

INTRODUCTION

Vocal loading tasks are often used to study how specific variables influence downstream vocal effort or fatigue. The current study introduces a novel vocal loading task, the Fluid Interval Test for Voice (FIT-V) that combines laryngeal diadochokinesis, intervallic rest and exercise, and fluid back pressure. To assess the differences between this novel task and existing vocal loading tasks, we measured vocal fold vibratory dose and perceived phonatory exertion across three 30-minute task conditions: a control loud oral reading task (LOR), a back pressure-resisted Fluid Interval Test for Voice (FIT-V5), and an unresisted Fluid Interval Test for Voice (FIT-V0).

METHODS

Following a training session, 30 participants completed the three tasks (LOR, FIT-V0, and FIT-V5) in counterbalanced order on different days. Vocal fold cycle (Aim 1A) and distance doses (Aim 1B) were collected continuously using a dosimeter. The overall perceived phonatory exertion (Aim 2A) was rated once per minute, while anatomically localized cognitive, laryngeal, thoracic, abdominal, and articulatory exertion (Aim 2B) were rated once at the end of each task. Statistical analyses examined the effects of task and task× time interactions on the dependent variables.

RESULTS

The FIT-V0 and FIT-V5 tasks imposed smaller vocal fold cycle doses (P < 0.001; Aim 1A) and distance doses (P < 0.001; Aim 1B) than the LOR task while eliciting comparable or greater magnitudes of overall perceived phonatory exertion (P = 0.003; Aim 2A). However, anatomically localized perceived exertion was greater in the abdomen and thorax (P < 0.05) and lesser in the anterior neck (P < 0.05) in the two FIT-V tasks relative to the LOR task (Aim 2B). Absolute forced vital capacity was a significant predictor of most forms of anatomically localized perceived exertion.

DISCUSSION

The unresisted FIT-V0 and the back pressure-resisted FIT-V5 tasks yielded similar profiles of overall perceived phonatory exertion, despite vocal fold vibratory doses roughly half that of the LOR task. However, the anatomically localized perceived exertion data underscored subtle across-task differences not apparent in the overall ratings, suggesting potentially distinct physiological and perceptual niches for the three task protocols.

Glottal Imaging Study Comparing Vowel Phonation with Semioccluded Vocal Tract Exercises (SOVTEs) Produced Loudly

OBJECTIVES

This study aimed to estimate vocal loading in loud phonation of a vowel and two widely used semiocclusion voice exercises (SOVTEs). Impact stress (IS) was estimated from glottal closing speed, inertial forces from the second derivative of glottal opening and closing.

STUDY DESIGN

Experimental study in vivo.

METHODS

A vocally healthy male sustained the [o:] vowel with habitual loudness and loudly: (1) without a tube, (2) into a silicone "Lax Vox" type tube (35 cm in length, 10 mm in diameter) outer end submerged 10 cm in water, and (3) into a straw (length 12.6 cm, diameter 2.5 mm) the outer end in air. He tried to use equal effort in all loud samples. High-speed video-laryngo-endoscopy was performed with a rigid scope. Oral air pressure (Poral) was registered in a mouthpiece through which the endoscope was inserted into the larynx and to which the tubes were attached air-tightly.

RESULTS

Compared with vowel phonation at habitual loudness, mean of maximal glottal width (max GW) increased by 44.1% for loud tube phonation and decreased by 1.8% for loud straw phonation, and mean absolute value of minimum GW time derivative dmin increased by 57.1% for tube and by 29.5% for straw suggesting faster glottal closing. Compared with loud vowel phonation, max GW increased by 22.6% for loud tube phonation, while it decreased by 16.6% for loud straw phonation. For the tube, dmindecreased by 7.6% and for the straw by 23.8%. Maximal acceleration (ACC) and deceleration (DC) values were larger for the tube and smaller for the straw than the values for both vowel phonations.

CONCLUSIONS

IS, deduced from dmin, increased in loud SOVTEs compared to vowel phonation at a conversational loudness, but remained lower in loud SOVTEs than in loud vowel phonation, particularly with a narrow straw, which also reduced inertial forces, as suggested by the reduced ACC and DC.

Consistency of the Signature of Phonotraumatic Vocal Hyperfunction Across Different Ambulatory Voice Measures

PURPOSE

Although different factors and voice measures have been associated with phonotraumatic vocal hyperfunction (PVH), it is unclear what percentage of individuals with PVH exhibit such differences during their daily lives. This study used a machine learning approach to quantify the consistency with which PVH manifests according to ambulatory voice measures. Analyses included acoustic parameters of phonation as well as temporal aspects of phonation and rest, with the goal of determining optimally consistent signatures of PVH.

METHOD

Ambulatory neck-surface acceleration signals were recorded over 1 week from 116 female participants diagnosed with PVH and age-, sex-, and occupation-matched vocally healthy controls. The consistency of the manifestation of PVH was defined as the percentage of participants in each group that exhibited an atypical signature based on a target voice measure. Evaluation of each machine learning model used nested 10-fold cross-validation to improve the generalizability of findings. In Experiment 1, we trained separate logistic regression models based on the distributional characteristics of 14 voice measures and durations of voicing and resting segments. In Experiments 2 and 3, features of voicing and resting duration augmented the existing distributional characteristics to examine whether more consistent signatures would result.

RESULTS

Experiment 1 showed that the difference in the magnitude of the first two harmonics (H1-H2) exhibited the most consistent signature (69.4% of participants with PVH and 20.4% of controls had an atypical H1-H2 signature), followed by spectral tilt over eight harmonics (73.6% participants with PVH and 32.1% of controls had an atypical spectral tilt signature) and estimated sound pressure level (SPL; 66.9% participants with PVH and 27.6% of controls had an atypical SPL signature). Additionally, 77.6% of participants with PVH had atypical resting duration, with 68.9% exhibiting atypical voicing duration. Experiments 2 and 3 showed that augmenting the best-performing voice measures with univariate features of voicing or resting durations yielded only incremental improvement in the classifier's performance.

CONCLUSIONS

Females with PVH were more likely to use more abrupt vocal fold closure (lower H1-H2), phonate louder (higher SPL), and take shorter vocal rests. They were also less likely to use higher fundamental frequency during their daily activities. The difference in the voicing duration signature between participants with PVH and controls had a large effect size, providing strong empirical evidence regarding the role of voice use in the development of PVH.

A Semiautomated Protocol Towards Quantifying Vocal Effort in Relation to Vocal Performance During a Vocal Loading Task

To increase the reliability and comparability of vocal loading studies, this paper proposes the use of a standardized approach with experiments that are [1] grounded on consistent definitions of terms related to vocal fatigue (vocal effort, vocal demand, and vocal demand response), and [2] designed to reduce uncertainty and increase repeatability. In the approach, a semi-automated vocal loading task that also increases efficiencies in collecting and preparing vocal samples for analysis was used to answer the following research question: To what extent is vocal effort and vocal demand response sensitive to changes in vocal demands (ie, noise only, noise plus duration)? Results indicate that the proposed protocol design consistently induced change in both vocal effort and vocal demand response, indicating vocal fatigue. The efficacy of future vocal loading studies would be improved by adopting a more consistent methodology for quantifying vocal fatigue, thus increasing interstudy comparability of results and conclusions.

Vocal Range Variations Elicited With a Standard Mandarin Reading Passage in Individuals With Voice Disorders

PURPOSE

This study examined whether the "Three Bears Passage" (TB), a standard Mandarin reading passage, could elicit significant vocal range variations in individuals with voice disorders. Relative sensitivity of TB versus another existing standard reading passage, "Passage in Mandarin" (PM), for differentiating between individuals with and without voice disorders was also evaluated.

METHOD

Forty-two individuals with normal voice and 30 individuals with voice disorders participated in the study. Maximum fundamental frequency (f0), minimum f0, mean f0, f0 range, maximum vocal intensity, minimum intensity, mean intensity, and intensity range of all participants reading aloud the two passages were measured with Praat to construct speech range profiles (SRPs).

RESULTS

Significantly larger vocal range was found for TB than for PM in individuals with voice disorders, including significantly higher maximum f0, mean f0, maximum intensity, mean intensity, and significantly larger f0 range and intensity range. Significantly more limited vocal range was observed in individuals with voice disorders than those without, with more obviously restricted SRPs while reading aloud TB compared to PM. Receiver operating characteristic analysis suggested that TB was more sensitive than PM in distinguishing between individuals with and without voice disorders.

CONCLUSIONS

Our findings supported the potential of TB as a standard clinical assessment tool for evaluating pathological changes in vocal range. Future studies should explore if therapeutic approaches based on the passage or variations of it could be developed for overcoming functional limitations and restrictions in vocal range for specific voice disorders.

Vocal Dose and Vocal Demands in Contemporary Musical Theatre

OBJECTIVE

To document and quantify vocal dose and student-singers' self-assessment during rehearsals for a contemporary musical theater production.

METHODS/DESIGN

Six student singers fastened the sensor from the KayPentax APM 3200 dosimeter to the lower neck to capture neck vibration data during their preparation for the musical Wonderland by Frank Wildhorn. Data were collected during 8-hour periods, at four different stages throughout the rehearsal process: beginning (music and choreography learning phase), middle (staging phase), and end (running the entire show/dress rehearsal phase), plus a post-production day once the production had concluded to establish a baseline vocal load. Students concurrently completed the EASE questionnaire1 after each data collection day.

RESULTS

The EASE score (Appendix 1) and demographics/perceptual questionnaire (Appendix 2) revealed that all subjects (three males and three females) found the singing role vocally and physically demanding but only two found the roles to be emotionally challenging. The musical score demanded a higher usage of chest register (judged perceptually) than mixed register from lead singers. All subjects' maximum fundamental frequency range exceeded the pitch range required by the score. The mean daily vibration dose (distance dose, as computed with Kay Pentax Software) of the three individual female singers' during rehearsals, 5,203 meters, was higher than the mean daily dose of the three male singers, 3,766 meters. The subjects' self-ratings on the EASE were not correlated with the distance dose.

CONCLUSIONS

A review of Wonderland's score and perceptual judgment of the singers' performances revealed extensive use of chest register, with belting and mix vocal strategies being the predominant stylistic choices. Students described the singing roles' vocal and physical requirements as more challenging than the character's emotional components. This pilot study provides information on the vocal dose for lead and ensemble singers in rehearsal for a Contemporary Musical Theatre production. Singers and voice professionals may find dosimetry a valuable tool for monitoring the vocal dose during rehearsals and performances.

The Effects of Reading Speed on Acoustic Voice Parameters and Self-reported Vocal Fatigue in Students

INTRODUCTION

Vocal loading tasks (VLTs) help researchers gather acoustic measurements and understand how a healthy speaker adjusts their voice in response to challenges. There is a dearth of evidence measuring the impact of speaking rate in VLTs on acoustic voice parameters and vocal fatigue.

OBJECTIVES

In the present study, the relationships between acoustic voice parameters and self-reported vocal fatigue were examined through an experimental VLT.

METHODS

38 students completed a 45-minute VLT which involved the recording of three randomized reading tasks. The tasks varied by the speed in which the words were presented (slow, medium, fast) on a computer monitor. Vocal fatigue ratings were measured subjectively using a Borg scale and negative adaptations to vocal loading were measured objectively using Sound Pressure Level (SPL, in dBA), fundamental frequency (fo, in semitones), and phonation time (Dt %).

RESULTS

Analysis indicated that vocal fatigue increases with time, and the slope of this relationship is affected by the speaking rate. SPL and fo increased with speaking rate and the standard deviation of SPL and fo decreased with speaking rate. On average, the male participants' phonation time values were 7.8% lower than the female participants. The rate of increase of vocal fatigue with time during the experiment was higher in the fast speaking style compared to the slow and medium ones.

CONCLUSION

The results provide support that the novel VLT altered multiple vocal parameters to induce measurable changes in vocal fatigue.

Quantifying Vocal Repertoire Tessituras Through Real-Time Measures

INTRODUCTION

Voice teachers use anecdotal evidence and experience in determining the appropriateness of repertoire for each student's development. Tessitura is important in that determination, but until recently a straightforward, repeatable, and quantifiable method for determining tessitura has not existed. However, technology exists to provide the means to estimate the tessituras of standard vocal repertoire by measuring sung pitch (fundamental frequency) and vocal dose (amount of phonation) in real-time performance.

PURPOSE

The purpose of this study was to examine the combined use of tessituragrams, Voice Range Profiles (VRPs), a singer's self-perception of a performance, and expert listeners perception of a performance towards the goal of a more systematic way of selecting appropriate voice repertoire for singers. The following research questions guided this investigation: 1) How do Performance Range Profiles (PRPs, performance-based tessituragrams computed from neck skin surface vibration during singing), compare to score-based tessituragrams of the same selection in the same key? 2) How do PRPs of the same vocal score compare when performed in three different keys? 3) How do singer VRPs compare with PRPs of three performances of a score, each sung in a different key? and 4) How do singer and expert panel perceptions of the selection's "fit" in three different keys compare with the alignment of each singer's VRP to their PRPs? Four female singers and five expert voice pedagogues were enlisted to address these questions.

RESULTS

The distribution (histogram) of the score-based tessituragram closely matched the distribution of performance-based tessituragrams (PRP), suggesting that score-based tessituragrams have promise in accurately reflecting the performance-based tessitura of a musical vocal work. Acquired data revealed relationships of practical importance between score-derived tessituragrams, PRPs, acquired VRPs, and singer perceptions of ease in singing. These data suggest that score-based tessituragrams aligned with singer VRPs show promise in repertoire selection. However, there was only a minor relationship between expert panel perceptions of ease in singing and the acquired PRPs or singer perceptions of ease. Creation of a score-based tessituragram database could be combined with singer VRPs to assist in appropriate repertoire selection.

The effect of swelling on vocal fold kinematics and dynamics

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

Quantifying the Occupational Voice Use of Teachers

Purpose

The teaching profession is a high-voice use occupation at elevated risk for developing voice disorders. Continued research on teachers' vocal demands is necessary to advocate for and establish vocal health programs. This study quantified ambulatory vocal dose measures for teachers during both on- and off-work periods, comparing their occupational voice use to that in other studies that have reported percent phonation ranging from 17% to 30%.

Method

Participants included 26 full-time, female school teachers between 23 and 55 years of age across multiple grades and subjects, including individuals with and without a voice disorder. Ambulatory voice data were collected from weeklong voice monitoring that recorded phonatory activity through anterior neck-surface vibration. Three vocal dose measures-time, cycle, and distance doses-were computed for each participant for three time periods: on-work weekdays, off-work weekdays, and off-work weekend days.

Results

The teachers' average percent phonation was 16.2% on-work weekdays, 8.4% off-work weekdays, and 8.0% off-work weekend days. No statistically significant differences for vocal dose measures were found between off-work weekdays and weekend days. Overall, all vocal dose measures were approximately 2 times higher during work relative to off-work time periods.

Conclusions

This study provides values for vocal dose measures for school teachers using ambulatory voice-monitoring technology. The vocal demands of this particular teacher sample and voice activity detection algorithm are potential factors contributing to percent phonation values on the lower end of the range reported in the literature. Future work is needed to continue to understand occupational voice use and its associated risks related to voice health, with the ultimate goal of preventing and managing voice disorders in individuals engaged in high-risk occupations.

Vocal Demands of Musical Theatre Rehearsals: A Dosimetry Study

OBJECTIVE

To investigate singers' vocal load by documenting three types of vocal doses (time, cycle, and distance doses) and sound pressure levels during the four phases of rehearsal and how the vocal doses vary between singers across rehearsals in the musical Nine, written by Maury Yeston.

METHODS/DESIGN

Five student-singers participating in the musical Nine gave informed consent to participate in the study. All five participants were assigned female at birth and female-identifying individuals. They attached a KayPENTAX APM 3300 dosimeter sensor to their lower neck and wore the accelerometer during four three-hour rehearsals throughout the rehearsal process (the music learning phase, the choreography learning phase, the blocking learning phase, and the dress rehearsal) of the musical. The dosimeter records neck vibrations at a rate of 20 samples per second. but it does not record linguistic content.

RESULTS

A dosimetric analysis of five student singers identified variability in voice production throughout the rehearsal process. According to the dosimetry findings, singers employed extensive low-frequency voicing below the first passaggio, with belting and mixed vocal strategies as the predominant stylistic choices when performing in Nine. Additionally, the singers used an occasional head voice effect at specific moments. The roles of Carla, Saraghina, La Fleur, and Ensemble One and Two required specific vocal ranges due to the musical score.

CONCLUSIONS

Researchers have yet to establish a safe baseline vocal dose for singers. The vocal dose is affected by many factors, such as duration of phonation, frequency range, SPL, and styles of vocalism required by the score. Louder and heavier vocalization produces larger distance doses, representing the cumulative load placed on vibrating tissue. The cycle dose, distance dose, and SPL reported in this study varied within and between singers. The phonation density graphs show this variability and the low tessitura required by the score. Time doses ranged from 4% to 7% of rehearsal time; this short dose suggests that the rehearsals provided healthy conditions for the successful rehearsal process with efficient attention to the vocalization of a score that requires heavy vocal styles, including belting. While the rehearsal pace was not alarming, the demands of the score alone may prove to be much greater than the vocal dose reported through the rehearsal. Further studies are needed to establish the overall dose of each Broadway role to serve as parameters for vocal pacing and voice care.

The Effect of Bilingualism on Production and Perception of Vocal Fry

AIMS

(1) Determine the difference in vocal fry phonation in English and Spanish productions among bilingual young adults, (2) Characterize the effect of spoken language and native language on vocal fry production among English-Spanish bilingual speakers, (3) Identify the effect of first and second language knowledge of the listener in the voice perceptual assessment, and (4) Define the effect of the environment of the assessment (in situ vs. online), in the voice perceptual assessment.

METHOD

Exploratory cross-sectional study of 34 bilingual (Spanish-English) speakers and six inexperienced listeners. Participating speakers produced two speech samples (one in English and one in Spanish). Six inexperienced monolingual and bilingual listeners performed the voice perceptual assessment of vocal fry, General grade of hoarseness, and Roughness using a 4-point rating scale.

RESULTS

Bilingual speakers used vocal fry more often when they were speaking in English (around 3%) compared with their production in Spanish (around 2%). Bilingual native English speakers used vocal fry more often during their productions in both languages compared with bilingual native Spanish speakers. Bilingual listeners had the highest agreement when identifying vocal fry in both languages.

CONCLUSIONS

Differences in production of vocal fry between native speakers of American English and native speakers of Spanish may be evidence of transferring of vocal behavior (such as vocal fry) from one language to the second one. In addition, being a bilingual listener may have an important effect on the perceptual identification of voice quality in English and Spanish, as well as vocal fry in English.

Acoustic Screening of the "Wet voice": Proof of Concept in an ex vivo Canine Laryngeal Model

BACKGROUND

Current protocols for bedside swallow evaluation have high rates of false negative results. Though experts are not consistently able to screen for aspiration risk by assessing vocal quality, there is emerging evidence that vocal acoustic parameters are significantly different in patients at risk of aspiration. Herein, we aimed to determine whether the presence of material on the vocal folds in an excised canine laryngeal model may have an impact on acoustic and aerodynamic measures.

METHODS

Two ex vivo canine larynges were tested. Three liquids of different viscosities (1:100 diluted glycerin, pure glycerin, and honey-thick Varibar) were placed on the vocal folds at a constant volume. Acoustic and aerodynamic measures were obtained in both adducted and abducted vocal fold configurations. Intraglottal high-speed imaging was used to approximate the maximum divergence angle of the larynges in the studied conditions and examine its relationship to vocal efficiency (VE) and acoustic measures.

RESULTS

In glottic insufficiency conditions only, we found that several acoustic parameters could predict the presence of material on the vocal folds. Based on the combination of the aerodynamic and acoustic data, we found that decreased spectral energy in the higher harmonics was associated with decreased VE in the presence of material on the vocal folds and/or glottic insufficiency.

CONCLUSION

Decreased spectral energy in the higher harmonics of the voice was found to be a potential biomarker of swallowing dysfunction, as it correlates with decreased vocal efficiency due to material on the vocal folds and/or glottic insufficiency, both of which are known risk factors for aspiration.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2517-2524, 2023.

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.

Voice Acoustics and Vocal Effort in Mask-Wearing Healthcare Professionals: A Comparison Pre- and Post-Workday

OBJECTIVE

We evaluated voice acoustics and self-perceptual ratings in healthcare workers required to wear face masks throughout their workday.

METHODS

Eighteen subjects (11 cisgender female, 7 cisgender male; M = 33.72 years, SD = 8.30) completed self-perceptual ratings and acoustic recordings before and after a typical workday. Chosen measures were specific to vocal effort, dysphonia, and laryngeal tension. Mixed effects models were calculated to determine the impact of session, mask type, sex, and their interactions on the set of perceptual and acoustic measures.

RESULTS

The subjects self-reported a significant increase in vocal effort following the workday. These perceptual changes coincided with an increase in vocal intensity and harmonics-to-noise ratio, but decrease in relative fundamental frequency offset 10. As expected, men and women differed in measures related to fundamental frequency and vocal tract length.

CONCLUSION

Healthcare professionals wearing masks reported greater vocal symptoms post-workday compared to pre-workday. These symptoms coincided with acoustic changes previously related to vocal effort; however, the degree of change was considered mild. Further research is needed to determine whether vocal hygiene strategies may reduce vocal symptoms in mask-wearing workers.

Investigating the Impact of Visual Input on Voice Production in Virtual Reality

OBJECTIVE

This study explored the independent effects of visual input on voice production using virtual reality. Specifically, its effects on acoustic voice parameters and vocal status ratings, with the hypothesis that larger (a virtual lecture hall and theater compared to an office) and more full virtual rooms (75% of the capacity compared to 45%) would result in changes to the voice parameters and vocal status ratings.

METHODS

Voice production from 30 vocally healthy participants was recorded in six virtual reality conditions. After each condition, the participants provided vocal status ratings. The voice recordings were processed to calculate mean and standard deviation of sound pressure level and fundamental frequency, mean pitch strength, time dose, and cepstral peak prominence smoothed. The effects of the virtual reality conditions on these voice acoustic parameters and the vocal status ratings were analyzed.

RESULTS

The full virtual reality rooms resulted in significantly higher vocal fatigue and vocal discomfort ratings. The larger virtual reality rooms were significantly related to increases in mean and the standard deviation of sound pressure level, mean pitch strength, and cepstral peak prominence smoothed.

CONCLUSIONS

This study demonstrated that visual size and visual fullness input during speech tasks have distinct effects on voice production and self-reported vocal status. Visual size is related to voice acoustic outcomes, while visual fullness is related to self-reported outcomes.

Systematic Review of Literature on Vocal Demand Response: Understanding Physiology, Measurements, and Associated Factors

PURPOSE

Considering the conceptual migration from vocal load and vocal loading to vocal demand and vocal demand response, this review of literature aimed to identify physiological explanations, reported measurements, and associated factors (vocal demands) reported in the literature when considering the phonatory response to a vocal demand.

METHODS

A systematic review of literature, following the PRISMA Statement, was conducted using Web of Science, PubMed, Scopus, and ScienceDirect. Data were analyzed and presented in two parts. First, a bibliometric analysis, co-occurrence analysis, and content analysis were performed. Three criteria that got article inclusion were defined: (1) written in English, Spanish, and Portuguese; (2) published between 2009 and 2021; and (3) focused on vocal load and loading, vocal demand response, and voice assessment parameters. A total of 54 publications met the criteria and were included in this review. The second part included a conceptual framework based on the content analysis of three aspects of vocal demand response: (1) physiological explanations, (2) reported measurements, and (3) vocal demands.

RESULTS AND CONCLUSION

As would be expected since vocal demand response is a relatively new term and not yet commonly used in literature when discussing way that the speakers respond to communicative scenarios, most of the studies reviewed (both historical and recent) still use the term of vocal load and vocal loading. Although there is a broad variety of literature discussing a wide range of vocal demands and voice parameters used to characterize the vocal demand response, results show that there is consistency across the studies. While vocal demand response is unique and intrinsic to the talker, associated factors that contribute to this response include both internal talker and external talker factors. Internal factors include muscle stiffness, viscosity in the phonatory system, vocal fold tissue damage, elevated sound pressure levels during occupational voice demands, extended periods of voice use, suboptimal body posture, difficulties in breathing technique, and sleep disturbances. Associated external factors include the working environment (noise, acoustics, temperature, humidity). In conclusion, although vocal demand response is intrinsic to the speaker, the speaker's response is affected by external vocal demands. However, due to the wide methods to evaluate vocal demand response, it has been difficult to establish its contribution to voice disorders in the general population and, specifically, among occupational voice users. This literature review identified commonly reported parameters and factors that may help clinicians and researchers define vocal demand response.

Do-It-Yourself Voice Dosimeter Device: A Tutorial and Performance Results

PURPOSE

Voice dosimeters gather voice production data in the daily lives of individuals with voice disorders. Additionally, voice dosimeters aid in understanding the pathophysiology of voice disorders. Previously, several voice dosimeters were commercially available. However, these devices have been discontinued and are not available to clinicians and researchers alike. In this tutorial, instructions for a low-cost, easy-to-assemble voice dosimeter are provided. This do-it-yourself (DIY) voice dosimeter is further validated based on performance results.

METHOD

Ten vocally healthy participants wore the DIY voice dosimeter. They produced a sustained /a/ vowel and read a text with three different vocal efforts. These tasks were recorded by the DIY voice dosimeter and a reference microphone simultaneously. The expanded uncertainty of the mean error in the estimation of four voice acoustic parameters as measured by the DIY dosimeter was performed by comparing the signals acquired through the reference microphone and the dosimeter.

RESULTS

For measures of sound pressure level, the DIY voice dosimeter had a mean error of -0.68 dB with an uncertainty of 0.56 dB. For fundamental frequency, the mean error was 1.56 Hz for female participants and 1.11 Hz for male participants, with an uncertainty of 0.62 Hz and 0.34 Hz for female and male participants, respectively. Cepstral peak prominence smoothed and L₁ minus L₂ had mean errors (uncertainty) of -0.06 dB (0.27 dB) and 2.20 dB (0.72 dB).

CONCLUSION

The mean error and uncertainties for the DIY voice dosimeter are comparable to those for the most accurate voice dosimeters that were previously on the market.

Examining the influence of epithelium layer modeling approaches on vocal fold kinematics and kinetics

Grouping the thin epithelium and thicker superficial lamina propria layers into a single cover layer has been widely adopted in finite element vocal fold models. Recent silicone vocal fold studies have suggested, however, that inclusion of a distinct epithelial layer leads to more physiologically representative motion. This study systematically explores the ramifications of incorporating an epithelial layer into a cover grouping for finite element vocal fold modeling. A membrane model for the epithelium is introduced to facilitate parametric investigation by reducing the mesh density requirement of the epithelium into a single infinitesimally thin layer. Excluding the epithelium entirely leads to increased energy in higher order modes and larger inferior-superior excursion of the folds. Integrating the epithelium into a cover layer with volume-weighted average stiffness results in similar kinematics to that of a model treating the epithelium as a distinct layer. However, the internal stress/strain and contact pressure during collision are higher, and viscous dissipation is lower, when the epithelium is integrated into the cover. Thus, careful treatment of the epithelium is recommended for finite element studies, particularly when employing the models for estimating measures dependent upon internal stress/strain and/or collision pressure, such as vocal dose.

Closed-loop network of skin-interfaced wireless devices for quantifying vocal fatigue and providing user feedback

Vocal fatigue is a measurable form of performance fatigue resulting from overuse of the voice and is characterized by negative vocal adaptation. Vocal dose refers to cumulative exposure of the vocal fold tissue to vibration. Professionals with high vocal demands, such as singers and teachers, are especially prone to vocal fatigue. Failure to adjust habits can lead to compensatory lapses in vocal technique and an increased risk of vocal fold injury. Quantifying and recording vocal dose to inform individuals about potential overuse is an important step toward mitigating vocal fatigue. Previous work establishes vocal dosimetry methods, that is, processes to quantify vocal fold vibration dose but with bulky, wired devices that are not amenable to continuous use during natural daily activities; these previously reported systems also provide limited mechanisms for real-time user feedback. This study introduces a soft, wireless, skin-conformal technology that gently mounts on the upper chest to capture vibratory responses associated with vocalization in a manner that is immune to ambient noises. Pairing with a separate, wirelessly linked device supports haptic feedback to the user based on quantitative thresholds in vocal usage. A machine learning-based approach enables precise vocal dosimetry from the recorded data, to support personalized, real-time quantitation and feedback. These systems have strong potential to guide healthy behaviors in vocal use.

A User-Centered Design Approach to Developing a Voice Monitoring System for Disorder Prevention

BACKGROUND

Many individuals will experience a voice disorder in their lifetime, especially occupational voice users. While a number of voice monitoring systems have been developed, most were designed with the clinician/researcher as the end user. For a patient to use these systems, they need field experts to help them interpret data from the system to understand its meaning. Most of these systems would have challenges in being used in a preventative context with the occupational voice user as the sole system user.

OBJECTIVE

The current study introduces a novel design approach: user-centered design (UCD) with paper prototypes in the creation of a voice monitoring system for voice disorder prevention (VDP). The goal of this design approach is to design systems that are engaging and intuitive for users so they will be interested in interacting with the system and be able to benefit from the system without the need of external support.

METHODS

The current study was conducted in two phases: an iterative design phase and a test phase. In the iterative design phase, 15 participants gave their opinions on the measures and feedback designs they felt would be the most beneficial to users. In the test phase, the researchers collected real voice data over multiple sessions for 18 additional participants and provided this data using the final feedback displays from the design phase.

RESULTS

By engaging in UCD, the researchers identified key design challenges for VDP: (1) educating the user, (2) balancing contextualization and granularity, and (3) addressing disconnection between user and system goals.

CONCLUSION

UCD holds promise for designing VDP systems that are both engaging and intuitive for occupational voice users.

Menopausal Voice-Related Work Limitation Scale (MenoVWL): Development and Validation

OBJECTIVES

Menopause has been reported to affect the voice of female professional voice users (FPVUs). The present study aims at the development and validation of a scale to measure self-perceived menopausal voice-related limitation to work in FPVUs, henceforth the Menopausal Voice-Related Work Limitation Scale (MenoVWL).

METHODS

Items were drawn from previous studies on impacts of sex steroid hormones on voice, available validated scales, and in-depth interviews with post-menopausal FPVUs. A preliminary version with 16 items was evaluated by a panel of 15 voice experts. The resulting revised version was filled in online, together with questions on current endocrinological reproductive status and related symptoms, history of amenorrhea, professional occupation, and demographic information. Responses concerning only professional voice users were selected and inclusive and exclusive criteria were applied for correct allocation of participants into pre- and post-menopausal stages within a restrict age range;192 responses were subject to factorial analysis for MenoVWL validation. Cronbach's alpha measured internal reliability. The scale was tested by comparing MenoVWL scores between pre- and post-menopausal FPVUs (98 and 94, respectively).

RESULTS

Thirteen items were retained from the expert panel evaluation. Items presented a high Content Validity Index (.94 out of 1) and high Item Acceptance Ratio (86.25 %). Both exploratory and confirmatory factorial analysis rendered one dimension scale with an excellent internal consistency (Cronbach's alpha = .9). The results of a Mann-Whitney test showed a higher MenoVWL score for post- as compared to pre-menopausal FPVUs (Z = - 2.818; P = .005).

CONCLUSIONS

MenoVWL is a comprehensive and validated scale with a known factor structure. It constitutes a health care and safety outcome self-perceived measure of value to the early detection of voice-related limitations to work in FPVUs during menopause.

Voice Biofeedback via Bone Conduction Headphones: Effects on Acoustic Voice Parameters and Self-Reported Vocal Effort in Individuals With Voice Disorders

PURPOSE

This study explores sidetone amplification (amplified playback of one's own voice) provided via bone conduction in participants with voice disorders. The effects of bone conduction feedback on acoustic voice parameters and vocal effort ratings are examined.

METHODS

Speech samples of 47 participants with voice disorders were recorded in three auditory feedback conditions: two with sidetone amplification delivered via bone conduction and one condition with no alteration of the feedback. After each task, the participants rated their vocal effort on a visual analog scale. The voice recordings were evaluated by a speech-language pathologist through the GRBAS scale and processed to calculate the within-participant centered sound pressure level (SPL) values, the mean pitch strength (PS), the time dose (Dt%), and cepstral peak prominence smoothed (CPPS). The effects of the feedback conditions on these acoustic parameters and vocal effort ratings were analyzed.

RESULTS

The high sidetone amplification condition resulted in a statistically significant decrease in the within-participant centered SPL values and mean pitch strength across all participants. The feedback conditions had no statistically significant effects on the vocal effort ratings, time dose (Dt%), or CPPS.

CONCLUSIONS

This study provides an evidence that bone conduction sidetone amplification contributes to a consistent adaptation in the within-participant centered SPL values (ΔSPL) in patients with vocal hyperfunction, glottal insufficiency, and organic/neurological laryngeal pathologies compared to conditions with no feedback.

Ambulatory Monitoring of Subglottal Pressure Estimated from Neck-Surface Vibration in Individuals with and without Voice Disorders

The aerodynamic voice assessment of subglottal air pressure can discriminate between speakers with typical voices from patients with voice disorders, with further evidence validating subglottal pressure as a clinical outcome measure. Although estimating subglottal pressure during phonation is an important component of a standard voice assessment, current methods for estimating subglottal pressure rely on non-natural speech tasks in a clinical or laboratory setting. This study reports on the validation of a method for subglottal pressure estimation in individuals with and without voice disorders that can be translated to connected speech to enable the monitoring of vocal function and behavior in real-world settings. During a laboratory calibration session, a participant-specific multiple regression model was derived to estimate subglottal pressure from a neck-surface vibration signal that can be recorded during natural speech production. The model was derived for vocally typical individuals and patients diagnosed with phonotraumatic vocal fold lesions, primary muscle tension dysphonia, and unilateral vocal fold paralysis. Estimates of subglottal pressure using the developed method exhibited significantly lower error than alternative methods in the literature, with average errors ranging from 1.13 to 2.08 cm H₂O for the participant groups. The model was then applied during activities of daily living, thus yielding ambulatory estimates of subglottal pressure for the first time in these populations. Results point to the feasibility and potential of real-time monitoring of subglottal pressure during an individual's daily life for the prevention, assessment, and treatment of voice disorders.

Introducing a New Dosimeter for the Assessment and Monitoring of Vocal Risk Situations and Voice Disorders

PURPOSE

There are many physiological parameters recorded by devices that are becoming more affordable, precise and accurate. However, the lack of development in the recording of voice parameters from the physiological or medical point of view is striking, given that it is a fundamental tool for the work of many people and given the high incidence and prevalence of voice pathologies that affect people's communication. In this paper we perform a complete literature review on the dosimeters used in voice research and to present a prototype dosimeter with a pilot study to show its capabilities.

METHOD

We conducted a literature review using the keywords [MONITORING], [PHONATION], [ACCUMULATOR], [PORTABLE], [DOSIMETRY], [VOICE] searching in PubMed, Trip Database, HONcode, and SciELO search engines. From our review of dosimeter designs, we created our own prototype consisting of two main components: a Knowles Electronics BU-7135-0000 accelerometer mounted on a neck brace; and the ultra-low power MSP430FR5994 microcontroller. The selected sampling frequency was 2048 Hz. The device calculates the F0 every 250 ms and the amplitude and phonation activity every 31.25 ms. A pilot study was conducted using 2 subjects: one male during 11 days and one female during 14 days.

RESULTS

This work includes devices that have been created during the last 45 years as tools for the diagnosis and monitoring of the treatment of cases of vocal pathology and for the detection of phonatory patterns or risk situations for developing voice disorders or vocal pathologies. We also present recordings with our new device on the pattern of daily talk time, the fundamental frequency and the relative intensity of two subjects on different days.

CONCLUSIONS

Interesting work has been done in the development of voice dosimeters with different approaches. In our experience it is not possible to access them for research and they are not yet in clinical use. It is possible that a joint approach with voice and voice disorders professionals and engineers working closely together could take advantage of current technology to develop a fully portable, useful, and efficient system.

An Electret-Powered Skin-Attachable Auditory Sensor that Functions in Harsh Acoustic Environments

Auditory sensors have shortcomings with respect to not only personalization with wearability and portability but also detecting a human voice clearly in a noisy environment or when a mask covers the mouth. In this work, an electret-powered and hole-patterned polymer diaphragm is exploited into a skin-attachable auditory sensor. The optimized charged electret diaphragm induces a voltage bias of >400 V against the counter electrode, which reduces the necessity of a bulky power source and enables the capacitive sensor to show high sensitivity (2.2 V Pa^-1 ) with incorporation of an elastomer nanodroplet seismic mass. The sophisticated capacitive structure with low mechanical damping enables a flat frequency response (80-3000 Hz) and good linearity (50-80 dB_SPL ). The hole-patterned electret diaphragms help the skin-attachable sensor detect only neck-skin vibration rather than dynamic air pressure, enabling a person's voice to be detected in a harsh acoustic environment. The sensor operates reliably even in the presence of surrounding noise and when the user is wearing a gas mask. Therefore, the sensor shows strong potential of a communication tool for disaster response and quarantine activities, and of diagnosis tool for vocal healthcare applications such as cough monitoring and voice dosimetry.

Prevalence of Work-Related Voice Disorders in Voice Professionals: Systematic Review and Meta-Analysis

OBJECTIVE

To analyze the prevalence of work-related voice disorders (WRVD) among the voice professionals.

METHODS

The study protocol was registered in PROSPERO (CRD42021250121). The search was performed in the Embase, Lilacs, Medline, SCOPUS, and Web of Sciences databases. There were no limitations to the year of publication and the search included observational studies which reported data on the prevalence of dysphonia in voice professionals measured through vocal complaints, vocal self-assessment, the auditory-perceptual judgment of the voice, and laryngoscopy examinations. The critical appraisal instrument for studies reporting prevalence data was used to analyze the risk of bias of the studies. Data analysis was performed using Jamovi and R software with a significance level of 5%.

RESULTS

The initial search identified 561 articles, 73 of which were finally included and analyzed. The total number of participants was 63,126. Dysphonia was diagnosed in 45,996 participants based on a vocal complaint, 12,843 using vocal self-assessment, 1,254 using the auditory-perceptual judgment, and 1,683 using laryngoscopies. The prevalence of total dysphonia was 44.0 (95% CI 38.47; 49.69). The prevalence of vocal complaints was 43.9% (95% CI 37.37; 50.52), 42.5% (95% CI 28.57; 57.08) for self-assessment, 53.0% (95% CI 29.87; 77.19) for auditory-perceptual judgment, and 36.9% (95% CI 18.62; 57.08) for laryngoscopic examination. In the auditory-perceptual judgment, voice professionals in class 3 (moderate quality, high demand) had a higher prevalence of dysphonia than those in class 4 (moderate quality, moderate demand) (P = 0.04). In the auditory-perceptual judgment (P = 0.04), there was a higher prevalence of dysphonia in teachers than among other voice professionals non-teachers, and in the laryngeal evaluation, no differences were found between professionals (P = 0.8).

CONCLUSION

There was a high prevalence of dysphonia in voice professionals, especially in the detection by auditory-perceptual judgment. High vocal demand and being a teacher influenced the increase in the prevalence of WRVD.

Collision Pressure and Dissipated Power Dose in a Self-Oscillating Silicone Vocal Fold Model With a Posterior Glottal Opening

PURPOSE

The goal of this study was to experimentally evaluate how compensating for the adverse acoustic effects of a posterior glottal opening (PGO) by increasing subglottal pressure and changing supraglottal compression, as have been associated with vocal hyperfunction, influences the risk of vocal fold (VF) trauma.

METHOD

A self-oscillating synthetic silicone model of the VFs with an airflow bypass that modeled a PGO was investigated in a hemilaryngeal flow facility. The influence of compensatory mechanisms on collision pressure and dissipated collision power was investigated for different PGO areas and supraglottal compression. Compensatory behaviors were mimicked by increasing the subglottal pressure to achieve a target sound pressure level (SPL).

RESULTS

Increasing the subglottal pressure to compensate for decreased SPL due to a PGO produced higher values for both collision pressure and dissipated collision power. Whereas a 10-mm² PGO area produced a 12% increase in the peak collision pressure, the dissipated collision power increased by 122%, mainly due to an increase in the magnitude of the collision velocity. This suggests that the value of peak collision pressure may not fully capture the mechanisms by which phonotrauma occurs. It was also found that an optimal value of supraglottal compression exists that maximizes the radiated SPL, indicating the potential utility of supraglottal compression as a compensatory mechanism.

CONCLUSIONS

Larger PGO areas are expected to increase the risk of phonotrauma due to the concomitant increase in dissipated collision power associated with maintaining SPL. Furthermore, the risk of VF damage may not be fully characterized by only the peak collision pressure.

Wearable Neck Surface Accelerometers for Occupational Vocal Health Monitoring: Instrument and Analysis Validation Study

BACKGROUND

Neck surface accelerometer (NSA) wearable devices have been developed for voice and upper airway health monitoring. As opposed to acoustic sounds, NSA senses mechanical vibrations propagated from the vocal tract to neck skin, which are indicative of a person's voice and airway conditions. NSA signals do not carry identifiable speech information and a speaker's privacy is thus protected, which is important and necessary for continuous wearable monitoring. Our device was already tested for its durable endurance and signal processing algorithms in controlled laboratory conditions.

OBJECTIVE

This study aims to further evaluate both instrument and analysis validity in a group of occupational vocal users, namely, voice actors, who use their voices extensively at work in an ecologically valid setting.

METHODS

A total of 16 professional voice actors (age range 21-50 years; 11 females and 5 males) participated in this study. All participants were mounted with an NSA on their sternal notches during the voice acting and voice assessment sessions. The voice acting session was 4-hour long, directed by a voice director in a professional sound studio. Voice assessment sessions were conducted before, during, and 48 hours after the acting session. The assessment included phonation tasks of passage reading, sustained vowels, maximum vowel phonation, and pitch glides. Clinical acoustic metrics (eg, fundamental frequency, cepstral measures) and a vocal dose measure (ie, accumulated distance dose from acting) were computed from NSA signals. A commonly used online questionnaire (Self-Administered Voice Rating questionnaire) was also implemented to track participants' perception of vocal fatigue.

RESULTS

The NSA wearables stayed in place for all participants despite active body movements during the acting. The ensued body noise did not interfere with the NSA signal quality. All planned acoustic metrics were successfully derived from NSA signals and their numerical values were comparable with literature data. For a 4-hour long voice acting, the averaged distance dose was about 8354 m with no gender differences. Participants perceived vocal fatigue as early as 2 hours after the start of voice acting, with recovery 24-48 hours after the acting session. Among all acoustic metrics across phonation tasks, cepstral peak prominence and spectral tilt from the passage reading most closely mirrored trends in perceived fatigue.

CONCLUSIONS

The ecological validity of an in-house NSA wearable was vetted in a workplace setting. One key application of this wearable is to prompt occupational voice users when their vocal safety limits are reached for duly protection. Signal processing algorithms can thus be further developed for near real-time estimation of clinically relevant metrics, such as accumulated distance dose, cepstral peak prominence, and spectral tilt. This functionality will enable continuous self-awareness of vocal behavior and protection of vocal safety in occupational voice users.

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.

Daily Phonotrauma Index: An Objective Indicator of Large Differences in Self-Reported Vocal Status in the Daily Life of Females With Phonotraumatic Vocal Hyperfunction

PURPOSE

The purpose of this study is to evaluate if the Daily Phonotrauma Index (DPI) can quantitatively discriminate large differences in overall vocal status in the daily life of patients with phonotraumatic vocal hyperfunction (PVH).

METHOD

For 1-4 weeks, 23 females with PVH wore an ambulatory voice monitor and answered three vocal status questions (i.e., difficulty producing soft, high-pitched phonation; discomfort; and fatigue) at the beginning, at 5-hr intervals, and the end of each day. DPI values were obtained for each patient's time periods of worst and best self-rated vocal status, and data for the group were analyzed for significant changes using a linear mixed-effects regression model.

RESULTS

The DPI was significantly lower during periods self-rated as "best vocal status" compared to during periods self-rated as "worst vocal status" (mean difference in DPI = 0.53) with a medium-to-large effect size (Cohen's d = -0.68).

CONCLUSIONS

In a group of patients with phonotraumatic lesions, the DPI indicated lower potential for phonotrauma during time periods of better vocal status compared to time periods of worse vocal status. Assuming that a large portion of variance in vocal status for patients with PVH is associated with the extent to which voicing is phonotraumatic, these results support the validity of obtaining estimates of DPI for much shorter time periods (i.e., an estimate every 2 min of voicing) than previous studies (i.e., a single estimate for the entire day or week). Future work can investigate the DPI's use for in-clinic assessment/treatment and ambulatory biofeedback and can gain further insights into phonatory mechanisms that underlie DPI via comparisons with other physiologically relevant measures and computational vocal fold modeling.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Automated Relative Fundamental Frequency Algorithms for Use With Neck-Surface Accelerometer Signals

OBJECTIVE

Relative fundamental frequency (RFF) has been suggested as a potential acoustic measure of vocal effort. However, current clinical standards for RFF measures require time-consuming manual markings. Previous semi-automated algorithms have been developed to calculate RFF from microphone signals. The current study aimed to develop fully automated algorithms to calculate RFF from neck-surface accelerometer signals for ecological momentary assessment and ambulatory monitoring of voice.

METHODS

Training a set of 2646 /vowel-fricative-vowel/ utterances from 317 unique speakers, with and without voice disorders, was used to develop automated algorithms to calculate RFF values from neck-surface accelerometer signals. The algorithms first rejected utterances with poor vowel-to-noise ratios, then identified fricative locations, then used signal features to determine voicing boundary cycles, and finally calculated corresponding RFF values. These automated RFF values were compared to the clinical gold-standard of manual RFF calculated from simultaneously collected microphone signals in a novel test set of 639 utterances from 77 unique speakers.

RESULTS

Automated accelerometer-based RFF values resulted in an average mean bias error (MBE) across all cycles of 0.027 ST, with an MBE of 0.152 ST and -0.252 ST in the offset and onset cycles closest to the fricative, respectively.

CONCLUSION

All MBE values were smaller than the expected changes in RFF values following successful voice therapy, suggesting that the current algorithms could be used for ecological momentary assessment and ambulatory monitoring via neck-surface accelerometer signals.

Relationships Among Personality, Daily Speaking Voice Use, and Phonotrauma in Adult Female Singers

PURPOSE

This study sought to determine whether personality traits related to extraversion and impulsivity are more strongly associated with singers with nodules compared to vocally healthy singers and to understand the relationship between personality and the types of daily speaking voice use.

METHOD

Weeklong ambulatory voice recordings and personality inventories were obtained for 47 female singers with nodules and 47 vocally healthy female singers. Paired t tests investigated trait differences between groups. Relationships between traits and weeklong speaking voice measures (vocal dose, sound pressure level [SPL], neck surface acceleration magnitude [NSAM], fundamental frequency, cepstral peak prominence [CPP], and the ratio of the first two harmonic magnitudes [H 1 -H 2]) were examined using pairwise Pearson r coefficients. Multiple regressions were performed to estimate voice parameters that correlated with two or more traits.

RESULTS

Singers with nodules scored higher on the Social Potency scale (reflecting a tendency toward social dominance) and lower on the Control scale (reflecting impulsivity) compared to the vocally healthy singers. In vocally healthy singers, vocal dose measures were positively correlated with a combination of Wellbeing (i.e., happiness) and Social Potency, mean SPL was positively correlated with Wellbeing, SPL variability was positively correlated with Social Potency and negatively with Harm Avoidance, and CPP mean was positively correlated with Wellbeing. Singers with nodules had a negative correlation between NSAM skewness and Social Potency. Both groups had negative correlations between H 1 -H 2 mean and Social Potency and Social Closeness.

CONCLUSIONS

Singers with nodules are more socially dominant and impulsive than vocally healthy singers. Personality traits are related to daily speaking voice use, particularly in vocally healthy singers. Individuals with higher levels of traits related to happiness and social dominance and lower Harm Avoidance tended to speak more, with higher laryngeal forces, with more SPL variability, and with more pressed glottal closure, which could increase risk of phonotrauma.

Estimation of Subglottal Pressure, Vocal Fold Collision Pressure, and Intrinsic Laryngeal Muscle Activation From Neck-Surface Vibration Using a Neural Network Framework and a Voice Production Model

The ambulatory assessment of vocal function can be significantly enhanced by having access to physiologically based features that describe underlying pathophysiological mechanisms in individuals with voice disorders. This type of enhancement can improve methods for the prevention, diagnosis, and treatment of behaviorally based voice disorders. Unfortunately, the direct measurement of important vocal features such as subglottal pressure, vocal fold collision pressure, and laryngeal muscle activation is impractical in laboratory and ambulatory settings. In this study, we introduce a method to estimate these features during phonation from a neck-surface vibration signal through a framework that integrates a physiologically relevant model of voice production and machine learning tools. The signal from a neck-surface accelerometer is first processed using subglottal impedance-based inverse filtering to yield an estimate of the unsteady glottal airflow. Seven aerodynamic and acoustic features are extracted from the neck surface accelerometer and an optional microphone signal. A neural network architecture is selected to provide a mapping between the seven input features and subglottal pressure, vocal fold collision pressure, and cricothyroid and thyroarytenoid muscle activation. This non-linear mapping is trained solely with 13,000 Monte Carlo simulations of a voice production model that utilizes a symmetric triangular body-cover model of the vocal folds. The performance of the method was compared against laboratory data from synchronous recordings of oral airflow, intraoral pressure, microphone, and neck-surface vibration in 79 vocally healthy female participants uttering consecutive /pæ/ syllable strings at comfortable, loud, and soft levels. The mean absolute error and root-mean-square error for estimating the mean subglottal pressure were 191 Pa (1.95 cm H2O) and 243 Pa (2.48 cm H2O), respectively, which are comparable with previous studies but with the key advantage of not requiring subject-specific training and yielding more output measures. The validation of vocal fold collision pressure and laryngeal muscle activation was performed with synthetic values as reference. These initial results provide valuable insight for further vocal fold model refinement and constitute a proof of concept that the proposed machine learning method is a feasible option for providing physiologically relevant measures for laboratory and ambulatory assessment of vocal function.

Voice amplifier: effects on dose and vocal intensity of teachers without dysphonia

PURPOSE

Analyze the interference of using the voice amplifier in vocal dose of non-dysphonic teachers.

METHODS

This is an experimental study comparing people from the same ambience compound for 20 teachers from municipal elementary school in Belo Horizonte/MG. After consent, the participants were requested to answer the vocal symptom scale questionnaire (ESV) and later participated in two different moments of the study, for which they randomly selected. In the first moment, the participants used only the vocal dosimeter and in the second, they used the vocal dosimeter and the voice amplifier. The measurements were recorded by the device for 1h40m, in the classroom that the teachers taught. The time between the two measurements was one week, with the same room, the same time and the same discipline being taught, at both times.

RESULTS

The intensity parameter was the only one that showed difference with the use of the voice amplifier.

CONCLUSION

Use voice amplification while non-dysphonic teachers are teaching doesn't affect the fundamental frequency and vocal dose measure in the acoustics parameters. The vocal intensity is smaller when teacher uses the vocal amplification.

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

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

Vocal fold dynamics in a synthetic self-oscillating model: Intraglottal aerodynamic pressure and energy

Self-sustained oscillations of the vocal folds (VFs) during phonation are the result of the energy exchange between the airflow and VF tissue. Understanding this mechanism requires accurate investigation of the aerodynamic pressures acting on the VF surface during oscillation. A self-oscillating silicone VF model was used in a hemilaryngeal flow facility to measure the time-varying pressure distribution along the inferior-superior thickness of the VF and at four discrete locations in the anterior-posterior direction. It was found that the intraglottal pressures during the opening and closing phases of the glottis are highly dependent on three-dimensional and unsteady flow behaviors. The measured aerodynamic pressures and estimates of the medial surface velocity were used to compute the intraglottal energy transfer from the airflow to the VFs. The energy was greatest at the anterior-posterior midline and decreased significantly toward the anterior/posterior endpoints. The findings provide insight into the dynamics of the VF oscillation and potential causes of some VF disorders.

Vocal fold dynamics in a synthetic self-oscillating model: Contact pressure and dissipated-energy dose

The energy dissipated during vocal fold (VF) contact is a predictor of phonotrauma. Difficulty measuring contact pressure has forced prior energy dissipation estimates to rely upon generalized approximations of the contact dynamics. To address this shortcoming, contact pressure was measured in a self-oscillating synthetic VF model with high spatiotemporal resolution using a hemilaryngeal configuration. The approach yields a temporal resolution of less than 0.26 ms and a spatial resolution of 0.254 mm in the inferior-superior direction. The average contact pressure was found to be 32% of the peak contact pressure, 60% higher than the ratio estimated in prior studies. It was found that 52% of the total power was dissipated due to collision. The power dissipated during contact was an order of magnitude higher than the power dissipated due to internal friction during the non-contact phase of oscillation. Both the contact pressure magnitude and dissipated power were found to be maximums at the mid anterior-posterior position, supporting the idea that collision is responsible for the formation of benign lesions, which normally appear at the middle third of the VF.

Comparison of vocal fatigue and vocal tract discomfort between teachers of normal pupils and teachers of mentally disabled pupils

PURPOSE

This study aims to study the comparison of vocal fatigue and vocal tract discomfort between teachers of normal pupils and teachers of mentally disabled pupils.

STUDY DESIGN

Cross-sectional study METHODS: Participants were 179 teachers (50 male, 129 female) and 30 non-teachers (14 male, 16 female) who participated in the current study. The teachers work in elementary schools. Furthermore, 87 of the teachers work for mentally disabled pupils at special elementary schools. Non-teachers were Ahvaz Jundishapur University of Medical Sciences employees who consider as the control group. They completed the Persian VFI and VTDp questionnaires three times, at the beginning, middle, and end of their office hours for 1 workday.

RESULTS

The current study's findings indicate that the Persian VFI and VTD scores of non-teachers were significantly lower than teachers' scores. Furthermore, teachers of mentally disabled pupils demonstrated higher values from teachers of normal pupils based on the Persian VFI and VTDp scores CONCLUSION: The study results showed that teachers experienced more vocal fatigue and vocal tract discomfort than non-teachers. Furthermore, teachers of mentally disabled pupils indicated more vocal fatigue, the larynx's physical discomfort, and vocal tract discomfort, but this difference was practically small.

Comparative Analysis of CNN and RNN for Voice Pathology Detection

Diagnosis on the basis of a computerized acoustic examination may play an incredibly important role in early diagnosis and in monitoring and even improving effective pathological speech diagnostics. Various acoustic metrics test the health of the voice. The precision of these parameters also has to do with algorithms for the detection of speech noise. The idea is to detect the disease pathology from the voice. First, we apply the feature extraction on the SVD dataset. After the feature extraction, the system input goes into the 27 neuronal layer neural networks that are convolutional and recurrent neural network. We divided the dataset into training and testing, and after 10 k-fold validation, the reported accuracies of CNN and RNN are 87.11% and 86.52%, respectively. A 10-fold cross-validation is used to evaluate the performance of the classifier. On a Linux workstation with one NVidia Titan X GPU, program code was written in Python using the TensorFlow package.

A Mandarin Chinese Reading Passage for Eliciting Significant Vocal Range Variations

Purpose There is a lack of standardized Mandarin reading text material that could potentially elicit significant variations in fundamental frequency (F0) and in vocal intensity for clinical voice evaluation. In this study, a phonetically balanced "Three Bears Passage" was developed based on the classical "Goldilocks" story for this purpose. The hypothesis was that the vocal range (F0 range and Intensity range) elicited while reading aloud the passage could be similar to that of the voice range profile (VRP) obtained with sustained vowel production and significantly different from that while reading an existing standard Mandarin passage. Method One hundred twenty young adults (60 men and 60 women, aged 25.22 ± 3.74 years) without vocal pathologies and vocal training participated in the study. Vocal range data, including F0-related measures and intensity-related measures, were obtained with Praat in order to construct VRPs for the sustained /a/ and to construct speech range profiles for passage reading. Results F0 range and intensity range for the new passage were significantly larger than those for the existing Mandarin passage for both male and female participants. In particular, the F0 range for the passage was not significantly different from that of the VRP for male participants. Conclusions These findings suggested that the new passage could allow individuals without vocal training to demonstrate a large vocal range in both F0 and vocal intensity, in a passage reading setting in a relatively short time. Further studies should be pursued with the passage to investigate the vocal range and vocal potential of individuals with voice disorders.

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.

Differences Between Female Singers With Phonotrauma and Vocally Healthy Matched Controls in Singing and Speaking Voice Use During 1 Week of Ambulatory Monitoring

Purpose Previous ambulatory voice monitoring studies have included many singers and have combined speech and singing in the analyses. This study applied a singing classifier to the ambulatory recordings of singers with phonotrauma and healthy controls to determine if analyzing speech and singing separately would reveal voice use differences that could provide new insights into the etiology and pathophysiology of phonotrauma in this at-risk population. Method Forty-two female singers with phonotrauma (vocal fold nodules or polyps) and 42 healthy matched controls were monitored using an ambulatory voice monitor. Weeklong statistics (average, standard deviation, skewness, kurtosis) for sound pressure level (SPL), fundamental frequency, cepstral peak prominence, the magnitude ratio of the first two harmonics (H₁-H₂ ), and three vocal dose measures were computed from the neck surface acceleration signal and separated into singing and speech using a singing classifier. Results Mixed analysis of variance models found expected differences between singing and speech in each voice parameter, except SPL kurtosis. SPL skewness, SPL kurtosis, and all H₁-H₂ distributional parameters differentiated patients and controls when singing and speech were combined. Interaction effects were found in H₁-H₂ kurtosis and all vocal dose measures. Patients had significantly higher vocal doses in speech compared to controls. Conclusions Consistent with prior work, the pathophysiology of phonotrauma in singers is characterized by more abrupt/complete glottal closure (decreased mean and variation for H₁-H₂ ) and increased laryngeal forces (negatively skewed SPL distribution) during phonation. Application of a singing classifier to weeklong data revealed that singers with phonotrauma spent more time speaking on a weekly basis, but not more time singing, compared to controls. Results are used as a basis for hypothesizing about the role of speaking voice in the etiology of phonotraumatic vocal hyperfunction in singers.