A Review of Measures of Vocal Effort With a Preliminary Study on the Establishment of a Vocal Effort Measure

Adult Normative Data for the OMNI-Vocal Effort Scale (VES)

PURPOSE

To establish normative values for the OMNI-Vocal Effort Scale (VES) in healthy adults without voice complaints. Secondary objective is to determine if there are differences in perceived vocal effort across age groups and between sexes.

STUDY DESIGN

Prospective data collection across groups.

METHOD

A nine-item survey was administered by speech-language pathologists with specialization in voice to consenting adults 18 years or older. Participants underwent an auditory perceptual evaluation of voice and answered questions regarding age, history of voice problems, history of voice surgery, smoking history and hearing loss. Participants were instructed to rate their perceived vocal effort in conversational speech using the OMNI-VES. Multivariant analysis was conducted.

RESULTS

Two hundred and fifty-one participants were recruited. The majority of adults without voice complaints reported that producing conversational voice was within the "extremely easy" to "easy" range, 0-3 (92.4%).

CONCLUSIONS

This study provides preliminary data for perceived vocal effort. The OMNI-VES may be a useful tool in understanding changes in perceived vocal effort as a result of treatment for voice disorders. Further normative data are needed between sexes, across the gender spectrum, and older adult populations. Future directions include examining the magnitude of difference between numeric values on the scale and use of the scale with other dysphonic populations.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3726-3731, 2024.

Effects of Back Pressure on the Feasibility and Tolerability of Laryngeal Diadochokinetic Exercise: A Pilot Study

BACKGROUND

The term vocal demand response refers to how speakers meet vocal demands. Vocal loading tasks with predetermined demand parameters (duration, pitch, loudness, etc) have been used in research to study the vocal demand response; these have historically consisted of loud sustained vowel and loud speech tasks. Tasks founded on laryngeal diadochokinesis (LDDK) may be viable alternatives, especially if demand parameters such as exercise-rest ratio and fluid back pressure are concurrently modulated.

OBJECTIVES

To explore the effects of four fluid back pressure conditions (0, 5, 10, and 15 cm H2O) on several measures of subjective participant experience, feasibility, and tolerability during intervallic laryngeal diadochokinetic exercise.

METHODS

Participants (n = 12) completed 15-minute trials of LDDK in 30-second rest and exercise intervals against four counterbalanced back pressure conditions: 0, 5, 10, and 15 cm H2O. The effects of back pressure on (1) ratings of perceived vocal exertion, (2) prevalence of adverse effects such as shortness of breath or lightheadedness, (3) subjective difficulty of sustaining LDDK, (4) number of exercise intervals completed, (5) rankings of participant-preferred back pressure levels, and (6) expert ratings of auditory-perceptual diadochokinetic strength were assessed descriptively.

RESULTS

Perceived vocal exertion, lightheadedness, and subjective laryngeal diadochokinetic difficulty increased as back pressure increased. Number of intervals completed, auditory-perceptual diadochokinetic strength, and participant rankings of back pressure conditions, by contrast, decreased as back pressure increased. 0 and 5 cm H2O were the most preferred back pressure conditions overall.

DISCUSSION

Fluid back pressure was feasible and broadly tolerated during 15-minute trials of vocal exercise. However, the transition from 5 → 10 cm H2O appeared to represent an inflection point in our results: a minority of participants did not tolerate exercise at 10 cm H2O, becoming a majority at 15 cm H2O. We conclude that fluid back pressure should be restricted to values between 0 and 10 cm H2O during LDDK.

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.

Effects of an 11-week vibro-tactile stimulation treatment on voice symptoms in laryngeal dystonia

Background

Laryngeal dystonia is a task-specific focal dystonia of laryngeal muscles that impairs speech and voice production. At present, there is no cure for LD. The most common therapeutic option for patients with LD involves Botulinum neurotoxin injections.

Objective

Provide empirical evidence that non-invasive vibro-tactile stimulation (VTS) of the skin over the voice box can provide symptom relief to those affected by LD.

Methods

Single-group 11-week randomized controlled trial with a crossover between two dosages (20 min of VTS once or 3 times per week) self-administered in-home in two 4-week blocks. Acute effects of VTS on voice and speech were assessed in-lab at weeks 1, 6 and 11. Participants were randomized to receive either 40 Hz or 100 Hz VTS.

Main outcome measures

Primary: smoothed cepstral peak prominence (CPPS) of the voice signal to quantify voice and speech abnormalities, and perceived speech effort (PSE) ranked by participants as a measure of voice effort (scale 1-10). Secondary: number of voice breaks during continuous speech, the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) inventory as a measure of overall disease severity and the Voice Handicap Index 30-item self report.

Results

Thirty-nine people with a confirmed diagnosis of adductor-type LD (mean [SD] age, 60.3 [11.3] years; 18 women and 21 men) completed the study. A single application of VTS improved voice quality (median CPPS increase: 0.41 dB, 95% CI [0.20, 0.61]) and/or reduced voice effort (PSE) by at least 30% in up to 57% of participants across the three study visits. Effects lasted from less than 30 min to several days. There was no effect of dosage and no evidence that the acute therapeutic effects of VTS increased or decreased longitudinally over the 11-week study period. Both 100 and 40 Hz VTS induced measurable improvements in voice quality and speech effort. VTS induced an additional benefit to those receiving Botulinum toxin. Participants, not receiving Botulinum treatment also responded to VTS.

Conclusion

This study provides the first systematic empirical evidence that the prolonged use of laryngeal VTS can induce repeatable acute improvements in voice quality and reductions of voice effort in LD.

Clinical trial registration

ClinicalTrials.gov ID: NCT03746509.

Evaluating Anterior and Posterior Oral Tongue Contributions to Pressure Generation: A Comparison Between Regular and Effortful Saliva Swallows

PURPOSE

This study determined the contributions of the anterior and posterior tongue regions in tongue pressure generation during regular saliva swallows (SSs) and effortful swallows (ESs) completed under two different instructions. The association between tongue pressure and perceived effort to swallow was also examined.

METHOD

Forty healthy adults without swallowing disorders participated in this study, divided into two age groups: 20 younger (Mage = 21.95 years, SD = 4.43) and 20 older (Mage = 70.10 years, SD = 4.30). Simultaneous data acquisition involved submental surface electromyography, tongue manometry, and a visual analog scale across swallowing conditions (SS, ES with tongue emphasis, and ES with pharyngeal squeezing). The main outcome measures were tongue pressure during swallowing and perceived effort to swallow.

RESULTS

Overall tongue pressure during ESs with tongue emphasis and with pharyngeal squeezing was greater than that during SSs (R2 = .78, p < .001). Moreover, tongue pressure during the ES with tongue emphasis was greater than that during the ES with pharyngeal squeezing (t = 25.63, p < .001). The posterior tongue region generated more pressure during SSs (R2 = .64, p < .001) and the ES with tongue emphasis (R2 = .55, p < .001) than the anterior tongue. Finally, a positive correlation was found between perceived effort and tongue pressure during swallowing (r = .75, 95% CI [0.72, 0.77]).

CONCLUSIONS

Tongue pressure generation was affected by the type of instruction used to elicit ESs, and the posterior tongue showed relatively greater pressure contributions than the anterior tongue for ESs with tongue emphasis and SSs. Furthermore, age-related declines in pressure generation during swallowing were not evidenced in this study, underscoring the ability of healthy older individuals to appropriately modulate lingual pressure during ESs. Last, our results showed that the visual analog scale is a simple tool for rating swallowing effort during ESs, supporting its potential clinical use to train ESs.

Vocal Effort and Acoustic Analysis of Gargle Phonation Versus Water Swallow in Patients With Muscle Tension Dysphonia: A Clinical Trial

PURPOSE

To determine the effects of gargle phonation (GP) on self-perceived vocal improvement, vocal effort, acoustic parameters, and speech rate in patients with muscle tension dysphonia (MTD). We hypothesized that GP would improve voice, reduce phonatory effort, and alter acoustic and speech measures.

STUDY DESIGN

Prospective randomized, single-blind cross-over clinical trial METHODS: Thirty-four participants (26 females, 8 males; average age 53 years) who were diagnosed with MTD completed the Voice Handicap Index-10 (VHI-10) and were assigned three study conditions: Baseline (B), GP, and Water Swallow (WS; sham), presented in one of two counterbalanced orders B-WS-GP (WS1st) or B-GP-WS (GP1st). Participants recorded stimuli from the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) and rated their perceived vocal effort and vocal improvement. F0, vocal intensity, cepstral peak prominence (CPP), and speaking rate were measured.

RESULTS

Average VHI-10 scores by group were 16 (min/max 2-29) for WS1st and 15 (min/max 3-40) for GP1st. About 73.5% reported more vocal improvement after GP, 17.65% after WS, and 8.8% noted no difference between conditions. Reduced effort was reported after GP, compared to B (P < 0.001) and WS (P = 0.005). Lower effort was also reported after the WS condition, compared to B (P = 0.011). Key acoustic findings included an increase in F0 after GP for sustained /i/ for females. CPP was significantly higher for females reading CAPE-V sentences after GP, when GP preceded WS, compared to B (P = 0.004) and WS (P = 0.003). Speech rate was faster for females after GP versus B (P = 0.029).

CONCLUSIONS

GP may be beneficial in the treatment of MTD. CPP may be a useful marker for vocal improvement after GP for women with mild MTD. Further studies would benefit from having more male participants and those with moderate and severe MTD.

Acoustic, Aerodynamic, Morphometric, and Perceptual Changes During and After Semi-Occluded Vocal Tract Exercise: An Integrative Review

OBJECTIVE

The body of literature discussing the acoustic, aerodynamic, perceptual, and morphometric changes that occur during and after semi-occluded vocal tract exercise (SOVTE) has dramatically expanded within the past 20 years. The current study integrates the literature on SOVTE from the 1990s onward, reviewing the technique's clinically relevant effects in vocally untrained adults both with and without dysphonia. The study aims to give clinicians actionable information on how SOVTEs alter vocal function in both normal and pathological states.

METHODS

The author queried the MEDLINE database for combinations of search terms related to semi-occluded vocal tract exercise. To improve article identification, the author also performed iterative citation webbing in which the reference lists of each article selected for full-text screening were cross-referenced against the articles returned in the initial MEDLINE search. Articles identified by iterative citation webbing that did not appear in the initial MEDLINE search were then screened individually. The second author independently verified adherence to the review's inclusion and exclusion criteria in both the initial search and data extraction phases.

RESULTS

The initial MEDLINE search returned 869 articles, 111 of which passed the title and abstract screening phase. Iterative citation webbing returned an additional 20 studies, resulting in a total of 131 articles that qualified for full-text screening. 53 articles passed full-text screening and were included in the current review.

DISCUSSION

Semi-occluded vocal tract exercise increases the inertive reactance of the glottis, vocal tract, and air column, as well as introducing flow resistance at the level of the lips or velopharyngeal port. Each of these mechanisms yields downstream acoustic, aerodynamic, morphometric, and perceptual changes, including reductions in phonation threshold pressure and perceived phonatory effort, improved spectral characteristics of the acoustic signal, attenuation of vocal fold impact stress as indexed by various metrics such as maximum area declination rate, and alterations to the physical dimensions of the vocal tract. Although few studies examined the duration of these changes post exercise, several RCTs support the assertion that SOVTE's effects can be sustained with regular practice over weeks or months, regardless of current vocal health status.

Shouting affects temporal properties of the speech amplitude envelope

Distinguishing shouted from non-shouted speech is crucial in communication. We examined how shouting affects temporal properties of the amplitude envelope (ENV) in a total of 720 sentences read by 18 Swiss German speakers in normal and shouted modes; shouting was characterised by maintaining sound pressure levels of ≥80 dB sound pressure level (dB-SPL) (C-weighted) at a 1-meter distance from the mouth. Generalized additive models revealed significant temporal alterations of ENV in shouted speech, marked by steeper ascent, delayed peak, and extended high levels. These findings offer potential cues for identifying shouting, particularly useful when fine-structure and dynamic range cues are absent, for example, in cochlear implant users.

Evaluating the Effect of Voice Quality Covariance on Auditory-Perceptual Evaluation Using a Novel Two-Dimensional Magnitude Estimation Task

PURPOSE

Most people with dysphonia present with voices that vary along more than one voice quality (VQ) dimension. This study sought to examine the effect of covariance between breathy and rough VQ in natural voices.

METHOD

A two-dimensional matrix of 16 /a/ vowels was selected such that two VQ dimensions (breathiness and roughness) were sampled on a 4-point severity scale (none, mild, moderate, and severe). Ten listeners evaluated 480 stimuli (16 stimuli × 10 repetitions × 3 blocks) on one-dimensional magnitude estimation (1DME) tasks and a novel two-dimensional magnitude estimation (2DME) task that allowed for simultaneous measurement of breathiness and roughness.

RESULTS

Data indicated high intra- and interrater reliabilities for both breathiness and roughness in the 2DME and 1DME tasks. Correlation analyses revealed a strong correlation between 2DME and 1DME judgments for breathiness and roughness (r > .95). There was also a minimal correlation between breathy and rough VQ in the 2DME task (r < .10).

CONCLUSIONS

Covarying roughness or breathiness had less impact on the perception of the other VQ in natural dysphonic voices in 2DME compared to 1DME. An understanding and quantification of the perceptual interactions among the dimensions will aid in the refinement of computational models and in the establishment of the validity of clinical scales for VQ perception.

Effects of warm-up exercises on self-assessed vocal effort

PURPOSE

An elevated sense of vocal effort due to increased vocal demand is frequently reported by patients with voice disorders. However, effects of vocal warm-up on self-assessed vocal effort have not been thoroughly examined. A recently developed version of the Borg CR-10 Scale facilitates vocal effort assessments, following different vocal warm-up tasks.

METHODS

Effects of a short (5 min) vocal warm-up on self-assessed vocal effort was evaluated using the Borg CR-10. Twenty-six vocally healthy participants (13F, 13M, mean age 22.6), in two randomised groups, underwent sessions of either reading aloud or semi-occluded vocal tract exercises (SOVTE). Vocal effort was evaluated at four times: pre to post vocal warm-up and two silence periods. Non-parametric analyses for repeated measures and calculations for within-subject standard deviation were applied in group comparisons.

RESULTS

Following vocal warm-up, vocal effort ratings were increased to a statistically significant degree in both intervention groups compared to baseline ratings. After a 5-min rest in silence following completion of the vocal warm-up, vocal effort ratings returned to baseline levels in both groups. The drop in ratings immediately post warm-up compared to 5 min later was statistically significant for the SOVTE group.

CONCLUSIONS

Five minutes of vocal warm-up caused increased self-perceived vocal effort in vocally healthy individuals. The increased sense of effort dissipated faster following warm-up for the SOVTE group. When using the Borg CR-10 scale to track vocal effort, it may be beneficial to apply experience-based anchors.

A Measure of Swallow Effort Using the Borg Category Ratio 10 Perceived Exertion Scale

PURPOSE

With the emphasis on patient-centered care, tools to adequately measure the experience of swallowing are an important part of clinical care. Swallowing effort is one such experience. However, few measurement tools capture swallowing effort in the moment of swallowing to quantify effort. The Borg Category Ratio 10 Perceived Exertion Scale (Borg CR 10), designed to track effort in a variety of tasks from lifting, breathing, and running, appears to be a likely candidate to measure swallowing effort in the moment of swallowing.

METHOD

In a quasi-random design, 32 healthy individuals, ages 40-80 years (average age: 63 years), consumed seven bolus consistencies in both small and large quantities, three times. Following each individual swallow, they rated the amount of effort it took to swallow each bolus using an adapted Borg CR 10 for swallowing effort.

RESULTS

Results showed significantly greater reports of swallowing effort on the Borg CR 10 for more adhesive consistencies, larger quantities, and increased number of swallows.

CONCLUSION

Results suggest that the Borg CR 10 is a reasonable measurement tool to capture patient-perceived effort in swallowing.

Decreased Speech Comprehension and Increased Vocal Efforts Among Healthcare Providers Using N95 Mask

Aim: N95 masks are recommended for the healthcare providers (HCPs) taking care of patients with coronavirus disease 2019. However, the use of these masks hampers communication. We aimed to evaluate the effect of N95 masks on speech comprehension among listeners and vocal efforts (VEs) of the HCPs.

Materials and Methods: This prospective study involved 50 HCPs. We used a single observer with normal hearing to assess the difficulty in comprehension, while VE was estimated in HCPs. The speech reception threshold (SRT), speech discrimination score (SDS), and VEs were evaluated initially without using N95 mask and then repeated with HCPs wearing N95 mask.

Results: The use of masks resulted in a statistically significant increase in mean SRT [4.25 (1.65) dB] and VE [2.6 (0.69)], with simultaneous decrease in mean SDS [19.2 (8.77)] (all p-values < 0.0001). Moreover, demographic parameters including age, sex, and profession were not associated with change in SRT, SDS, and VE (all p-values > 0.05).

Conclusion: Though use of N95 masks protects the HCPs against the viral infection, it results in decreased speech comprehension and increased VEs. Moreover, these issues are universal among the HCPs and are applicable to the general public as well.

Interactions Between Breathy and Rough Voice Qualities and Their Contributions to Overall Dysphonia Severity

PURPOSE

Dysphonic voices typically present multiple voice quality dimensions. This study investigated potential interactions between perceived breathiness and roughness and their contributions to overall dysphonia severity.

METHOD

Synthetic stimuli based on four talkers were created to systematically map out potential interactions. For each talker, a stimulus matrix composed of 49 stimuli (seven breathiness steps × seven roughness steps) was created by varying aspiration noise and open quotient to manipulate breathiness and superimposing amplitude modulation of varying depths to simulate roughness. One-dimensional matching (1DMA) and magnitude estimation (1DME) tasks were used to measure perceived breathiness, roughness, their potential interactions, and overall dysphonia severity. Additional 1DME tasks were used to assess a set of natural stimuli that varied along both breathiness and roughness.

RESULTS

For the synthetic stimuli, the 1DMA task indicated little interaction between the two voice qualities. For the 1DME task, breathiness magnitude was influenced by roughness step to a greater extent than roughness magnitude was influenced by breathiness step. The additive contributions of breathiness and roughness to overall severity gradually diminished with increasing breathiness and roughness steps, possibly reflecting a ceiling effect in the 1DME task. For the natural stimuli, little consistent interaction was observed between breathiness and roughness.

CONCLUSIONS

The matching task revealed minimal interaction between perceived breathiness and roughness, whereas the magnitude estimation task revealed some interaction between the two qualities and their cumulative contributions to overall dysphonia severity. Task differences are discussed in terms of differences in response bias and the role of perceptual anchors.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21313701.

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.

The Influence of Face Masks on Verbal Communication in Persian in the Presence of Background Noise in Healthcare Staff

Wearing face masks has resulted in verbal communication being more challenging during the COVID-19 pandemic. This study aimed to investigate the effect of face masks on the speech comprehensibility of Persian nurses in healthcare settings. Twenty female nurses from the governmental hospitals randomly participated in an experiment on seven typical commercial face masks at two background noise levels. Nurses' speech intelligibility from a human talker when wearing each face mask was determined based on the speech discrimination score. The vocal effort of nurses wearing each face mask was determined based on the Borg CR10 scale. Based on the linear mixed model, the speech intelligibility of nurses from a human speaker wearing surgical masks, N95 masks, and a shield with face masks were approximately 10%, 20%, and 40-50% lower, respectively, than no-mask conditions (p < 0.01). The background noise decreased the speech intelligibility of nurses by approximately 22% (p < 0.01). The use of a face shield further decreased speech intelligibility up to 30% compared to using a face mask alone (p < 0.01). The vocal efforts of nurses when wearing surgical masks were not significant compared with the baseline vocal efforts (p > 0.05); however, vocal efforts of nurses when wearing N95 and N99 respirators were at an unacceptable level. The face masks had no considerable effect on the speech spectrum below 2.5 kHz; however, they reduced high frequencies by different values. Wearing face masks has a considerable impact on the verbal communication of nurses in Persian. The level of background noise in the healthcare setting can aggravate the effect sizes of face masks on speech comprehensibility.

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

OBJECTIVES/HYPOTHESIS

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

STUDY DESIGN

Prospective, repeated-measures design.

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

3 Laryngoscope, 131:2732-2739, 2021.

Psychometric Analysis of an Ecological Vocal Effort Scale in Individuals With and Without Vocal Hyperfunction During Activities of Daily Living

Objective The purpose of this study was to examine the psychometric properties of an ecological vocal effort scale linked to a voicing task. Method Thirty-eight patients with nodules, 18 patients with muscle tension dysphonia, and 45 vocally healthy control individuals participated in a week of ambulatory voice monitoring. A global vocal status question was asked hourly throughout the day. Participants produced a vowel-consonant-vowel syllable string and rated the vocal effort needed to produce the task on a visual analog scale. Test-retest reliability was calculated for a subset using the intraclass correlation coefficient, ICC(A, 1). Construct validity was assessed by (a) comparing the weeklong vocal effort ratings between the patient and control groups and (b) comparing weeklong vocal effort ratings before and after voice rehabilitation in a subset of 25 patients. Cohen's d, the standard error of measurement (SEM), and the minimal detectable change (MDC) assessed sensitivity. The minimal clinically important difference (MCID) assessed responsiveness. Results Test-retest reliability was excellent, ICC(A, 1) = .96. Weeklong mean effort was statistically higher in the patients than in controls (d = 1.62) and lower after voice rehabilitation (d = 1.75), supporting construct validity and sensitivity. SEM was 4.14, MDC was 11.47, and MCID was 9.74. Since the MCID was within the error of the measure, we must rely upon the MDC to detect real changes in ecological vocal effort. Conclusion The ecological vocal effort scale offers a reliable, valid, and sensitive method of monitoring vocal effort changes during the daily life of individuals with and without vocal hyperfunction.

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

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

Fatigue, effort and vocal discomfort in teachers after teaching activity

PURPOSE

Investigate vocal fatigue and its relationship with the sensation of phonatory effort and discomfort in the vocal tract of teachers after a week of activity.

METHODS

Cross-sectional, quantitative study, involving 40 teachers with complaints of vocal fatigue. Procedures performed at the beginning and end of the week, before the classes start were Vocal Fatigue Index, Borg Scale, Vocal Tract Discomfort Scale, and voice recording for perceptual analysis.

RESULTS

There were no changes in phonatory effort and in frequency and intensity of discomfort in vocal tract. In relation to the VFI, in the domains of fatigue and vocal limitation and physical discomfort associated with the voice, teachers started and ended the week with values compatible with dysphonia. In the vocal restriction domain, they started the week with values compatible with vocal healthy individuals and at the end of the week they had scores compatible with dysphonia. In recovery with vocal rest, the pre and post values were below the cut-off score, meaning less vocal recovery. The greater the sensation of vocal fatigue, the greater the perception of phonatory effort; more frequent is the sensation of tightness, dryness, sore, sensitive and irritated throat and more intense the sensations of discomfort in the vocal tract: tightness, dryness, itching, sensitive and irritated throat.

CONCLUSION

Teachers perceive an increase in vocal fatigue, without changes in phonatory effort and vocal tract discomfort after one week of class. The greater the perception of vocal fatigue, the greater the sensation of effort and phonatory discomfort.

Relationship Between Tasked Vocal Effort Levels and Measures of Vocal Intensity

Purpose Patients with voice problems commonly report increased vocal effort, regardless of the underlying pathophysiology. Previous studies investigating vocal effort and voice production have used a range of methods to quantify vocal effort. The goals of the current study were to use the Borg CR100 effort scale to (a) demonstrate the relation between vocal intensity or vocal level (dB) and tasked vocal effort goals and (b) investigate the repeated measure reliability of vocal level at tasked effort level goals. Method Three types of speech (automatic, read, and structured spontaneous) were elicited at four vocal effort level goals on the Borg CR100 scale (2, 13, 25, and 50) from 20 participants (10 females and 10 males). Results Participants' vocal level reliably changed approximately 5 dB between the elicited effort level goals; this difference was statistically significant and repeatable. Biological females produced a voice with consistently less intensity for a vocal effort level goal compared to biological males. Conclusions The results indicate the utility of the Borg CR100 in tracking effort in voice production that is repeatable with respect to vocal level (dB). Future research will investigate other metrics of voice production with the goal of understanding the mechanisms underlying vocal effort and the external environmental influences on the perception of vocal effort.

Oropharyngeal Geometry and the Singing Voice: Immediate Effect of Two Semi-Occluded Vocal Tract Exercises

PURPOSE

The aim of this study was to verify the immediate effect of a flexible resonance tube in water and of lip trill on oropharyngeal geometry and vocal acoustic parameters of singers without vocal symptoms.

METHODS

Twenty-two adult singers participated in the study. They had an average age of 27 (±4.8) years. Participants were split into two groups: a group composed of 12 singers who performed the flexible resonance tube (FRT) exercise and a group of 10 singers who performed the Lip Trill technique (LTT). Acoustic pharyngometry and acoustic analysis of the voice were used to assess oropharyngeal geometry before and after the exercises.

RESULTS

After performing the techniques, the vocal tract length was longer in the group that performed the FRT, compared to the one that performed the LTT. In the acoustic evaluation, there was an improvement in the glottal to noise excitation ratio and a decrease in noise in the group of singers who performed the LTT. In the analysis by sex men had a longer oral cavity compared to women and after application of the techniques greater volume of the vocal tract.

CONCLUSION

There was variation in the oropharyngeal geometry with the FRT, while the LTT had a positive effect on the vocal acoustic parameters related to glottal noise.

Toward a Consensus Description of Vocal Effort, Vocal Load, Vocal Loading, and Vocal Fatigue

Purpose The purpose of this document is threefold: (a) review the uses of the terms "vocal fatigue," "vocal effort," "vocal load," and "vocal loading" (as found in the literature) in order to track the occurrence and the related evolution of research; (b) present a "linguistically modeled" definition of the same from the review of literature on the terms; and (c) propose conceptualized definitions of the concepts. Method A comprehensive literature search was conducted using PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scientific Electronic Library Online. Four terms ("vocal fatigue," "vocal effort," "vocal load," and "vocal loading"), as well as possible variants, were included in the search, and their usages were compiled into conceptual definitions. Finally, a focus group of eight experts in the field (current authors) worked together to make conceptual connections and proposed consensus definitions. Results The occurrence and frequency of "vocal load," "vocal loading," "vocal effort," and "vocal fatigue" in the literature are presented, and summary definitions are developed. The results indicate that these terms appear to be often interchanged with blurred distinctions. Therefore, the focus group proposes the use of two new terms, "vocal demand" and "vocal demand response," in place of the terms "vocal load" and "vocal loading." We also propose standardized definitions for all four concepts. Conclusion Through a comprehensive literature search, the terms "vocal fatigue," "vocal effort," "vocal load," and "vocal loading" were explored, new terms were proposed, and standardized definitions were presented. Future work should refine these proposed definitions as research continues to address vocal health concerns.

Translation and cross-cultural adaptation of the Brazilian version of the Adapted Borg CR10 for Vocal Effort Ratings

PURPOSE

To develop the cultural and linguistic adaptation of the Brazilian version of the Adapted Borg CR10 for Vocal Effort Ratings.

METHODS

The instrument Adapted Borg CR10 for Vocal Effort Ratings was translated into Portuguese by two Brazilian bilingual speech-language pathologists, whose translations were compiled into one version. Back-translation into English was performed by a third bilingual Brazilian speech-language pathologist who did not participate in the previous stages. After translation and back-translation, the items of the translated version were compared with the original instrument and discrepancies were modified by consensus of a committee composed of three speech-language pathologists, resulting in the version translated into Brazilian Portuguese entitled Escala Borg CR10-BR adaptada para esforço vocal. For cultural equivalence of the Portuguese version, the option "not applicable" was added to the categorical scale and 15 individuals with dysphonia, with otorhinolaryngological medical diagnosis, responded to the Escala Borg CR10-BR adaptada para esforço vocal after reading the perceptual-auditory evaluation protocol CAPE-V phrases.

RESULTS

During the process of translation and cultural adaptation, no item was changed and/or eliminated from the questions. The Escala Borg CR10-BR adaptada para esforço vocal kept the same structure as the original, with a scale ranging from 0 to 10, with 0 being "no vocal effort at all" and 10 being "maximum vocal effort".

CONCLUSION

The Brazilian version of the Adapted Borg CR10 for Vocal Effort Ratings, entitled Escala Borg CR10-BR adaptada para esforço vocal, presents cultural and linguistic equivalence to the original instrument.

Associations of Education and Training with Perceived Singing Voice Function Among Professional Singers

BACKGROUND

The educational backgrounds of professional singers vary greatly and span from no formal training to advanced degrees in music or theater. Consequently, professional singers have a wide range of knowledge regarding basic voice care. The objective of this study was to examine associations between singers' educational backgrounds, specifically their knowledge of vocal pedagogy and awareness of vocal health, and their perceptions of their current vocal function associated with singing.

STUDY DESIGN

Cross sectional survey.

METHODS

An online survey was distributed nationwide to over 1,000 self-identifying as a professional singer working full time as a performer. The survey included 54 questions about their background education, performance history, years of professional experience, affiliation to a professional union, general health and wellness, and the Evaluation of the Ability to Sing Easily (EASE), a 20-item scale to assess singers' perceptions of the current status of their vocal function.

RESULTS

A total of 396 amateur and professional singers completed the survey yielding a 40% response rate. Of 396 surveys received, 154 were excluded because the respondent was not a professional singer and/or the survey was incomplete and four were excluded because the respondent was <19 years old (396-158 = 238). Of 238, 199 completed the EASE (included in this analysis sample). The respondents identified their primary singing genre(s) as follows: 29% classical, 22% musical theatre, 45% both classical and musical theatre, and 5% other contemporary styles. Overall mean (SD, range) Rasch converted EASE score was 19.9 units (9.0, 0-50). Mean EASE score was 19.6 for primary classical, 22.7 for primary musical theatre, 18.4 for both classical and musical theatre, and 23.3 for other contemporary styles (P = 0.03). Participants who were older, had more years of singing training, had a college degree or higher in music, studied classical singing in an academic or private setting, and those who received education in vocal health had significantly lower (better) EASE scores (P-values <0.05).

CONCLUSIONS

Professional singers' perception of their current vocal function differed according to their singing genre, age, extent and type of vocal training and vocal health education. Singing teachers, speech-language pathologists, and physicians could use these results to tailor voice education messages to professional singers. This knowledge could help voice care professionals to educate and treat this elite group of voice users to avoid long-term sequelae from suboptimal voice care.

Cognitive influences on perceived phonatory exertion using the Borg CR10

Objectives: The purpose of the present study was to examine the nature of the relationship between perceptions of vocal and mental (cognitive) effort during reading and speaking tasks.Methods: One hundred and four young, healthy adult participants were randomized into one of three groups. Each group performed a writing task meant to elicit low mental effort, high mental effort, or high mental effort followed by a period of relaxation. Participants then engaged in reading and speaking tasks, meant to elicit high (suppression of a prepotent desire to speak louder) or low (no suppression of a prepotent desire to speak louder) mental effort, and completed ratings of mental effort and vocal effort via adapted versions of the Borg CR10.Results: Findings indicate that ratings of perceived mental and vocal effort are related to one another, evidenced by strong correlations, and additional analyses reveal that mental effort might drive this relationship.Conclusions: Perceptions of vocal effort appear to mirror ratings of mental effort during tasks for which vocal activity is relatively stable but cognitive demands fluctuate. The possibility that perceptions of mental effort might influence perceptions of vocal effort should be considered when creating reliable and valid measures of vocal effort as well as when interpreting currently adapted measures of vocal effort in the clinical context.

The Relationship Between Physiological Mechanisms and the Self-Perception of Vocal Effort

Purpose This study aimed to examine the relationship between a large set of hypothesized physiological measures of vocal effort and self-ratings of vocal effort. Method Twenty-six healthy adults modulated speech rate and vocal effort during repetitions of the utterance /ifi/, followed by self-perceptual ratings of vocal effort on a visual analog scale. Physiological measures included (a) intrinsic laryngeal tension via kinematic stiffness ratios determined from high-speed laryngoscopy, (b) extrinsic suprahyoid and infrahyoid laryngeal tension via normalized percent activations and durations derived from surface electromyography, (c) supraglottal compression via expert visual-perceptual ratings, and (d) subglottal pressure via magnitude of neck surface vibrations from an accelerometer signal. Results Individual statistical models revealed that all of the physiological predictors, except for kinematic stiffness ratios, were significantly predictive of self-ratings of vocal effort. However, a combined regression model analysis yielded only 3 significant predictors: subglottal pressure, mediolateral supraglottal compression, and the normalized percent activation of the suprahyoid muscles (adjusted R 2 = .60). Conclusions Vocal effort manifests as increases in specific laryngeal physiological measures. Further work is needed to examine these measures in combination with other contributing factors, as well as in speakers with dysphonia.

Continuous Vocal Fry Simulated in Laboratory Subjects: A Preliminary Report on Voice Production and Listener Ratings

PURPOSE

Vocal fry is prevalent in everyday speech. However, whether the use of vocal fry is detrimental to voice production is unclear. This preliminary study assessed the effects of using continuous vocal fry on voice production measures and listener ratings.

METHOD

Ten healthy individuals (equal male and female, mean age = 22.4 years) completed 2 counterbalanced sessions. In each session, participants read in continuous vocal fry or habitual voice quality for 30 min at a comfortable intensity. Continuous vocal fry was simulated. Phonation threshold pressure (PTP10 and PTP20), cepstral peak prominence, and vocal effort ratings were obtained before and after the production of each voice quality. Next, 10 inexperienced listeners (equal male and female, mean age = 24.1 years) used visual analog scales to rate paired samples of continuous vocal fry and habitual voice quality for naturalness, employability, and amount of listener concentration.

RESULTS

PTP10 and vocal effort ratings increased after 30 min of continuous vocal fry. Inexperienced listeners rated continuous vocal fry more negatively than the habitual voice quality.

CONCLUSIONS

Thirty minutes of simulated, continuous vocal fry worsened some voice measures when compared with a habitual voice quality. Samples of continuous vocal fry were rated as significantly less employable, less natural, and requiring greater listener concentration as compared with samples of habitual voice quality. Future studies should include habitual users of vocal fry to investigate speech stimulability and adaptation with cueing to further understand pathogenesis of vocal fry.

Sense of Effort and Fatigue Associated With Talking After Total Laryngectomy

PURPOSE

Sense of effort and fatigue associated with talking was compared in individuals with and without a total laryngectomy.

METHOD

An online survey of individuals using tracheoesophageal speech (TES; n = 222), electrolaryngeal speech (ELS; n = 132), esophageal speech (n = 41), and laryngeal speech (LS; n = 112) asked about 3 domains of effort when talking: frequency of occurrence, withdrawal from talking, and location in the body. Three aspects of fatigue were explored: frequency of occurrence, fatigue type, and duration of talking before fatigue.

RESULTS

Alaryngeal groups reported significantly more talking-related effort and fatigue than the LS group. Sixty-three percent of all respondents indicated that effort caused them to talk less, with no group differences on this item. Significantly more effort was localized to the lips and tongue by ELS compared with TES and LS groups. Both the ELS and TES groups had higher shoulder/arm effort when talking compared with the esophageal speech and LS groups. ELS respondents reported less fatigue than the TES group. When fatigue was present, the TES group had more physical and less mental fatigue than the ELS group. The duration of talking before experiencing fatigue was significantly shorter for the alaryngeal groups compared with the LS group.

CONCLUSIONS

Effort and fatigue associated with talking are a common report for individuals using alaryngeal speech. The location of effort within the body and the type of fatigue experienced vary to some extent across alaryngeal speaking methods.

Validation of the OMNI vocal effort scale in the treatment of adductor spasmodic dysphonia

OBJECTIVES

To establish the validity of the OMNI Vocal Effort Scale (OMNI-VES) for resistance exercise, a single-question pictorial scale, in voice-related perceived exertion. Additionally, the study aimed to assess the role of the OMNI-VES as an outcome measurement in the treatment of adductor spasmodic dysphonia (ADSD).

METHODS

A prospective validation study was conducted on 226 participants. The case group was comprised of 178 patients receiving botulinum toxin (BTX) injections for ADSD and 48 controls without a voice disorder. Prior to a planned injection, the participants were asked to complete the OMNI-VES and the Voice-Related Quality-of-Life (V-RQOL) questionnaires, and the clinician completed the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V). A subgroup of 17 patients were administered a repeat assessment 1 month after injection.

RESULTS

There was a weak correlation between the OMNI-VES and the V-RQOL score (Tau-b = -0.252, P < 0.001), and no significant correlation with the CAPE-V. Participants with ADSD had significantly higher OMNI-VES scores compared with normal controls, 5.07 ± 2.18 and 1.47 ± 2.28, respectively (P value < 0.0001). The average OMNI-VES score significantly improved 1 month following a BTX injection, from 6 ± 2.4 to 3.4 ± 2.8 (P value = 0.0003). Eighty-eight percent of the patients demonstrated a decrease in the OMNI-VES score following injection, whereas only 47% demonstrated an improvement in the V-RQOL score.

CONCLUSION

The OMNI-VES is a validated tool for rating perceived voice-related exertion in people with ADSD and can be used for evaluating response to BTX injection treatment.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:448-453, 2019.

The relationship between acoustical and perceptual measures of vocal effort

Excessive vocal effort is a common clinical voice symptom, yet the acoustical manifestation of vocal effort and how that is perceived by speakers and listeners has not been fully elucidated. Here, 26 vocally healthy adults increased vocal effort during the production of the utterance /ifi/, followed by self-ratings of effort on a 100 mm visual analog scale. Twenty inexperienced listeners assessed the speakers' vocal effort using the visual sort-and-rate method. Previously proposed acoustical correlates of vocal effort were calculated, including: mean sound pressure level (SPL), mean fundamental frequency (f o), relative fundamental frequency (RFF) offset cycle 10 and onset cycle 1, harmonics-to-noise ratio (HNR), cepstral peak prominence and its standard deviation (SD), and low-to-high (L/H) spectral ratio and its SD. Two separate mixed-effects regression models yielded mean SPL, L/H ratio, and HNR as significant predictors of both speaker and listener ratings of vocal effort. RFF offset cycle 10 and mean f o were significant predictors of listener ratings only. Therefore, speakers and listeners attended to similar acoustical cues when making judgments of vocal effort, but listeners also used additional time-based information. Further work is needed to determine how vocal effort manifests in the speech signal in speakers with voice disorders.

Review of differential diagnosis and management of spasmodic dysphonia

PURPOSE OF REVIEW

The recent literature on spasmodic dysphonia is reviewed with regard to pathogenesis, differential diagnosis, treatment options, audits, and current methods of management.

RECENT FINDINGS

Advances in technology have enabled clinicians to better understand the connection between brain and laryngeal function and dysfunction. Refinements in imaging and genetic investigation techniques have led to advances in the understanding of the underlying mechanism of this neurolaryngeal disorder. Development of diagnostic assessment tools and measures of quality of life hold the potential to improve treatment and care.

SUMMARY

Fifty articles published between 2014 and 2015 were selected for this review. The sources were drawn from several clinical specialties: 54% come under the scope of laryngology, 32% from neurology, and 14% from other areas. It remains poorly understood, misdiagnosed, and underdiagnosed. Its identification, diagnosis, treatment selection, and coordination of care require an expert specialist multidisciplinary team. More training is required to help people who have this chronic and psychosocially disabling voice disorder, which impinges on all aspects of their lives. Spasmodic dysphonia is now classified as a 'rare' disease in the United States. This designation will assist in international standards of diagnosis, assessment, treatment, and management.

Magnitude of Neck-Surface Vibration as an Estimate of Subglottal Pressure During Modulations of Vocal Effort and Intensity in Healthy Speakers

PURPOSE

This study examined the relationship between the magnitude of neck-surface vibration (NSVMag; transduced with an accelerometer) and intraoral estimates of subglottal pressure (P'sg) during variations in vocal effort at 3 intensity levels.

METHOD

Twelve vocally healthy adults produced strings of /pɑ/ syllables in 3 vocal intensity conditions, while increasing vocal effort during each condition. Measures were made of P'sg (estimated during stop-consonant closure), NSVMag (measured during the following vowel), sound pressure level, and respiratory kinematics. Mixed linear regression was used to analyze the relationship between NSVMag and P'sg with respect to total lung volume excursion, levels of lung volume initiation and termination, airflow, laryngeal resistance, and vocal efficiency across intensity conditions.

RESULTS

NSVMag was significantly related to P'sg (p < .001), and there was a significant, although small, interaction between NSVMag and intensity condition. Total lung excursion was the only additional variable contributing to predicting the NSVMag-P'sg relationship.

CONCLUSIONS

NSVMag closely reflects P'sg during variations of vocal effort; however, the relationship changes across different intensities in some individuals. Future research should explore additional NSV-based measures (e.g., glottal airflow features) to improve estimation accuracy during voice production.

Estimating Vocal Effort from the Aerodynamics of Labial Fricatives: A Feasibility Study

OBJECTIVE AND HYPOTHESIS

Vocal effort in loud voice is produced with increased subglottal pressure during vowels and increased supraglottal pressure during consonants. In the paper, our main objective is to check whether it was supported by a parallel increase in the airflow resistance of the laryngeal articulator and of the supralaryngeal articulator, here the lips.

STUDY DESIGN AND METHOD

For this comparison, our choice fell on the fricative consonants, as their production allows perfectly synchronous air pressure and airflow measurements. Also, the calculation of the real instantaneous aerodynamic resistance is possible with fricatives-as it is with vowels-whereas it is not possible with plosives. The present feasibility study on a healthy subject is based on direct subglottal and intraoral pressures and airflow measured for /f/ or /v/ and from the contiguous vowel produced in VCVCV nonsense words at different levels of intensity.

RESULTS AND CONCLUSION

The results support that the airflow resistances at the lips and that at the larynx are quite parallel. The airflow resistance at the lips during labial fricative production could provide a good picture of the laryngeal resistance during the production of continuous speech. This suggests clinical applications using both noninvasive inferred measurements of subglottal pressure variation and direct noninferred airflow measurements from more natural speech production tasks.

Using the Borg CR10 Physical Exertion Scale to Measure Patient-perceived Vocal Effort Pre and Post Treatment

OBJECTIVES

Reduction of vocal effort is a therapeutic goal in resonant voice therapy and in the treatment of a variety of voice disorders. The Borg CR10 is a perceived effort scale that is widely accepted across a wide variety of disciplines. The purpose of the present study was to examine (1) the utility of an anchored, adapted Borg CR10 in observing treatment-related vocal effort reduction and (2) the convergent validity of the Borg CR10 in its relation to Voice Handicap Index (VHI) item 14.

STUDY DESIGN

This is a pretest-posttest experimental design.

METHODS

A total of 36 individuals with phonotraumatic hyperfunctional voice disorders completed item 14 of the VHI and the Borg CR10 at the start and completion of four sessions of resonant voice therapy treatment.

RESULTS

Scores from the Borg CR10 significantly differentiated pre- from post-therapy perceived effort levels. Convergent validity was demonstrated through significant associations with scores from item 14 of the VHI.

CONCLUSION

The anchored Borg CR10 is an easy to use clinical tool to capture treatment-related vocal effort reduction. Whereas VHI item 14 indicates how frequently increased perceived effort is experienced, the Borg CR10 captures the severity of perceived effort used. Thus, the two measures complement each other.