Does Vocal Fatigue Negatively Affect Low Vocal Range in Professional, Female Opera Singers? A Survey Study and Single-Subject Pilot Study

OBJECTIVE

1. To survey how vocal fatigue manifests itself in the vocal range of a sample of professional, female opera singers. 2. To assess laryngeal videostroboscopic changes of one professional, female opera singer before and after extended operatic singing.

METHODS

Survey study: 296 professional, female opera singers were recruited to participate in an anonymous research survey querying the temporary impact of vocal fatigue in professional, female opera singers. 46.3% of participants described themselves as singing mainstage roles at large, A-level opera houses. Singers were asked to report where in their vocal range they experienced the effects of vocal fatigue and could choose more than one response. Single-subject study: One professional, female opera singer (the author) underwent two laryngeal videostroboscopic exams pre and post vocal loading. The exams were evaluated and compared independently by two blinded laryngologists.

RESULTS

The results of the survey found that 42.9% of the total responses from professional, female opera singers indicated a temporary impact on the lower middle range (≈C4-F4) as a result of vocal fatigue. 36.5% of participants experienced a temporary impact on their lowest range (≈below C4) and 19.6% reported a temporary impact on their higher range due to vocal fatigue. The results of the single-subject study showed reduced glottal closure pattern in the postloading, lower middle range, head voice condition.

CONCLUSIONS

A large proportion (64.9%) of the professional, female opera singers surveyed reported increased difficulty navigating their lower middle range and/or lowest range after extended operatic singing. These results support the single-subject study, which found that after vocal loading, there was a decrease in glottal competence while singing in head voice in the lower middle range.

Prevalence of Vocal Fatigue Due to the Use of Facial Protective Gear in Teaching Medical Professionals

Since the COVID-19 pandemic, masks have become far more widely used by doctors and are now commonplace in the hospital, with many professionals still wearing them for extended amounts of time. Emerging literature describing numerous mask-related difficulties prompted the authors to conduct a study aimed at assessing the self-perceived impact on voices of teaching doctors due to facial protective gear. In this study carried out from October 2021 to March 2022, data was gathered from 170 pre-, para-, and clinical professionals who were involved in offline teaching. Over half of teaching medical professionals were found to be vocally fatigued. Pre and para-clinical professionals have greater vocal tiredness and avoidance than clinical doctors (p = 0.016). The type of mask used does not make a significant difference in degree of vocal fatigue. Individuals with lingering respiratory difficulties following COVID-19 were significantly more vocally fatigued than their recovered peers (p value for tiredness and avoidance = 0.010). Thus, teaching doctors are at risk of impaired quality of life due to vocal fatigue. Further research on vocal habits and rest practices in the study population may help identify the most effective interventions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04350-8.

Cross-Cultural Adaptation, Validation, and Diagnostic Accuracy of the Voice Fatigue Handicap Questionnaire-Persian Version

OBJECTIVE

The current study aimed to determine the psychometric characteristics of a translated version of the Voice Fatigue Handicap Questionnaire in Persian by examining the validity, reliability, and diagnostic accuracy using data collected from people with and without dysphonia.

STUDY DESIGN

Cross-sectional study.

METHOD

The original questionnaire was translated from Italian to Persian using the International Quality of Life Assessment criteria. The translated version was completed by 122 people with dysphonia and 49 people without dysphonia. The validity, reliability, and diagnostic accuracy of the Voice Fatigue Handicap Questionnaire Persian-version were evaluated. A panel of five voice-specializing Speech and Language Pathologists and 20 native Persian speakers (with dysphonia) in a pilot study confirmed the translated version for content and face validity, respectively. The internal consistency was evaluated by Cronbach's alpha and McDonald omega coefficients. The intraclass correlation coefficient was used to examine the test-retest reliability. For discriminant validity, the mean total and subscale scores of respondents with and without dysphonia were compared through independent t tests. Finally, sensitivity, specificity, and ideal cut-off value were determined using the receiver-operating characteristic curve.

RESULTS

Cronbach's alpha coefficient was 0.965 for the total score (functional: α = 0.883, emotional: α = 0.944, physical: α = 0.917). Also, the McDonald omega coefficient was 0.966 for the total score (functional: ω = 0.889, emotional: ω = 0.933, physical: ω = 0.920). The intraclass correlation coefficient for measuring the test-retest reliability was 0.971 for the total score (functional: ICC=0.937, emotional: ICC=0.954, physical ICC=0.976). The results of the independent samples t tests indicated that the dysphonia group obtained significantly higher mean scores (total and subscale scores) than the group without dysphonia. The cutoff value of 13.5 was determined based on the optimal balance of sensitivity (0.992) and specificity (0.918).

CONCLUSION

The Voice Fatigue Handicap Questionnaire-Persian version is a valid and reliable questionnaire to identify individuals at high risk of vocal fatigue and subsequent dysphonia.

Phonatory Tasks and Outcome Measures for Assessing Vocal Fatigue: A Scoping Review

OBJECTIVES

To map the phonatory tasks and the result measures used to evaluate vocal fatigue in vocally healthy individuals.

METHODS

This is a scoping review based on the following research question: What are the phonatory tasks and outcome measures used for the evaluation of vocal fatigue in vocally healthy individuals? The construction of the search strategy followed the PCC strategy; population: vocally healthy adult individuals; concept: phonatory tasks and vocal evaluation measures; and context: vocal fatigue. The search was performed electronically in the databases Medline (PubMed), LILACS (BVS), SCOPUS (Elsevier), Web of Science (Clarivate), EMBASE, and COCHRANE. A manual search in the references of the selected articles and in the journal with the highest number of publications was also performed. The selection of articles was based on reading the titles, abstracts, and full text, applying the eligibility criteria. The selected articles were related to the evaluation of vocal fatigue in healthy individuals from a predetermined vocal load task. Data regarding the characteristics of the publication, sample, phonatory tasks, and outcomes were extracted. The results were presented in a descriptive format, due to a frequency distribution analysis.

RESULTS

In total, 3756 studies were identified during the search, of which 60 were selected. The most used vocal load activity was the reading task, with duration ranging from 46 to 120 minutes. The (1) sustained vowel /a/ and (2) the reading of texts and phrases, both in usual intensity and frequency without the interference of the researcher, were the most used evaluation tasks. The most used outcome measures are the following: (1) acoustic parameters-fundamental frequency [fo] (mean, variance), sound pressure level (mean), local jitter (%), local shimmer (%), cepstral peak prominence (mean); (2) vocal self-assessment by the validated instruments-Perceived Phonatory Effort Scale, Visual Analog Scale, Borg-CR-10 Scale.

CONCLUSIONS

There is a diversity of phonatory tasks and outcome measures recurrently used in scientific articles to evaluate the signs of vocal fatigue in vocally healthy individuals. The most used vocal sample to evaluate vocal fatigue was the sustained vowel /a/ in habitual intensity and frequency without the interference of the researcher. The most frequently reported outcome measures for the assessment of immediate vocal fatigue effects were the acoustic analysis and vocal self-assessment.

Vocal Fatigue Experiences and Mitigation Strategies in the Sacred Harp Singing Community

OBJECTIVES

Sacred Harp singers sing at a high volume for sustained periods of time without collective warm-up or cool-down exercises, ostensibly putting them at elevated risk for vocal fatigue (VF) and associated vocal pathologies. Participants are also likely to lack formal vocal training. The purpose of this study was to (1) assess singers' experiences with VF, (2) document singers' strategies for mitigating VF, and (3) determine whether vocal training was associated with decreased vocal difficulties.

STUDY DESIGN

Self-reporting via online questionnaire containing quantitative and qualitative items.

METHODS

This study employed an online questionnaire that combined demographic items, open-ended questions, and the Evaluation of the Ability to Sing Easily (EASE). Participants were recruited at one in-person event and via social media and a mailing list.

RESULTS

This study returned 134 valid responses. Singers with formal choral experience scored lower on the EASE and two subscales, but length of experience had no impact. There were no correlations between vocal training and EASE scores. Women scored higher on the EASE than men and nonbinary individuals, while age, length of experience with Sacred Harp singing, and frequency of attendance at annual singing events were all negatively correlated with EASE score. Singers reported a wide range of mitigation strategies, most of which are unique to the Sacred Harp context.

CONCLUSIONS

Sacred Harp singers do not appear to struggle more with VF than other populations of singers. However, a few characteristics of their practice put them at risk, and many singers would benefit from professional guidance concerning vocal health.

Psychometric Properties of the Vocal Fatigue Handicap Questionnaire in Kannada Among Teachers

BACKGROUND

As the literature review suggests, most professional voice users, such as teachers and singers, are prone to vocal abuse or misuse and frequently experience vocal fatigue. Therefore, validating the Vocal Fatigue Handicap Questionnaire among professional voice users with and without the symptoms of vocal fatigue might provide appropriate external validity of the questionnaire.

OBJECTIVE

The objective of the study was to validate the Kannada version of the Vocal Fatigue Handicap Questionnaire (VFHQ-K) among a cohort of Kannada-speaking primary and secondary school teachers with and without self-reported vocal fatigue symptoms.

STUDY DESIGN

This was a validation study.

METHOD

The study consisted of two groups of participants. Group 1 included 40 teachers with self-reported vocal fatigue symptoms, and Group 2 included 57 teachers without self-reported vocal fatigue symptoms. The VFHQ-K was administered to each participant after obtaining informed consent. The questionnaire was again readministered between 1 and 2 weeks to assess the test-retest reliability. All the responses that were obtained were tabulated for analysis.

RESULTS

The VFHQ-K demonstrated good test-retest reliability, internal consistency, and acceptable discriminant validity. The cutoff value of VFHQ-K obtained in the present study between the teachers with and without self-reported symptoms of vocal fatigue was much less than the cutoff values reported by the earlier version of VFHQ-K.

CONCLUSION

The VFHQ-K can be a helpful tool in the early identification of teachers with vocal fatigue and in improving the vocal health of professional voice users.

Adaptation and Validation of the Mandarin (Simplified) Chinese Version of the Voice Fatigue Handicap Questionnaire

OBJECTIVE

The aim of this study was to assess the reliability and validity of the Mandarin (simplified) Chinese version of the Voice Fatigue Handicap Questionnaire (MC-VFHQ).

METHODS

A total of 358 participants were included from June 2020 to April 2021: 243 patients with voice disorders (patient group) and 115 vocally healthy individuals (control group). The internal consistency, test-retest reliability, content validity, clinical, sensitivity and specificity were analyzed, and the cutoff point was determined.

RESULTS

The internal consistency of the MC-VFHQ was high, and the internal consistency assessed with Cronbach α coefficients for the subscale scores ranged from 0.821 to 0.983; the values for the total score were 0.952 and 0.943 in the patient and control group, respectively. Test-retest reliability was high for the total score (intraclass correlation coefficient (ICC) = 0.924) and the subscales (ICCs = 0.969, 0.939, 0.922). The patient group had significantly higher total score, subscale scores, and item scores than the control group (P < 0.001). The cutoff point for screening between the two groups was 63.5, with a sensitivity of 84.8% and a specificity of 84.30%.

CONCLUSIONS

The MC-VFHQ is a valid and reliable tool for identifying individuals with probable vocal fatigue. It has good reliability, validity, sensitivity, and specificity in the Mandarin Chinese-speaking population.

Investigation of the Relationship Between Vocal Fatigue, Quality of Life, and Compliance With Vocal Hygiene in Professional Voice Users

PURPOSE

Intensive voice use may lead to the development of voice disorders or voice complaints, such as vocal fatigue, for professional voice users (teachers, academics, call center workers, actors, singers, speech and language therapists, voice trainers, and religious officials). Vocal fatigue has a detrimental effect on occupational, emotional, and social performance, besides the quality of life of the individual. The effect of voice hygiene interventions on voice fatigue is not fully known. The results of studies conducted with different occupational groups are inconsistent. The present study aims to analyze the relationship between vocal fatigue and voice-related quality of life (V-RQOL) in professional voice users, and the impact of vocal hygiene on vocal fatigue.

METHODS

Participants (24 male, 90 female), who were professional voice users without any diagnosis of voice disorders or voice complaints were divided into two groups low vocal hygiene compliance (LVH; n = 66) and high vocal hygiene compliance (HVH; n = 48). In this study, vocal fatigue was measured by the vocal fatigue index (VFI), and V-RQOL was measured by the voice handicap index (VHI-10) and V-RQOL.

RESULTS

VFI subscales (tiredness, avoidance, physical discomfort) have a moderate positive correlation with VHI-10 and V-RQOL, which indicates that there is a significant relationship between vocal fatigue and quality of life amongst professional voice users. While there was no significant difference between the LVH and HVH groups in terms of quality of life, it was found that the vocal fatigue level of the LVH group was higher.

CONCLUSION

This study of professional voice users with healthy voices reveals a relationship between vocal fatigue and V-RQOL. Vocal hygiene compliance may affect professional voice users' vocal fatigue symptoms; the low-compliant group has higher levels of tiredness, avoidance, and physical discomfort. The findings highlight the importance of raising awareness of the problems of professional voice users, even though they have healthy voices and the need for vocal hygiene education programs that target them.

Cross-cultural adaptation and validation of vocal fatigue index (VFI) to Chinese language

Objectives: This study aimed to translate the Vocal Fatigue Index (VFI) into Simplified Chinese and test its reliability and validity in mainland China. Methods: The original English version of the VFI was translated and adapted to a Simplified Chinese version (VFI -SC). Fifty-four participants with voice disorders and 21 healthy controls completed the VFI-SC. Sixteen participants with voice disorders completed it again two weeks later. Reliability, validity, and receiver operating characteristic (ROC) of the VFI-SC were analyzed. Results: The Cronbach's alpha values for the VFI factor scores were found to be 0.930 for tiredness and avoidance of voice use (factor 1), 0.878 for physical discomfort with voice use (factor 2), and 0.915 for improvement of symptoms with voice rest (factor 3). The test-retest reliability was 0.967 for all three factors. There was a significant difference between the total scores of the patient group and the control group (p < 0.01). Factor 1 and factor 2 were positively correlated with the Voice Handicap Index (VHI-30). The ROC curves showed acceptable intrinsic accuracies for factor 1 (AUC = 0.883), factor 2 (AUC = 0.901), and factor 3 (AUC = 0.800), with cutoff scores of 22, 7, and 9, respectively. Conclusions: This study provides preliminary evidence that the VFI-SC has good reliability and validity. It can be used to screen for clinical symptoms of voice fatigue in mainland China.

Cross-Linguistic Adaptation of Vocal Fatigue Handicap Questionnaire into Kannada (VFHQ-K)

BACKGROUND

It is often considered appropriate to assess vocal fatigue using a self-reported tool or a subjective measure, as vocal fatigue is primarily described through self-reported symptoms. The vocal fatigue handicap questionnaire (VFHQ) is a self-rated questionnaire that addresses the concern of vocal fatigue in persons with voice disorders. Adapting and validating this questionnaire into the Kannada language can be helpful in assessing the physical, emotional, and functional effects of vocal fatigue among Kannada-speaking individuals.

OBJECTIVE

Adaptation and Validation of the VFHQ into the Kannada language.

STUDY DESIGN

A validation study.

METHOD

Initially, the VFHQ was translated into Kannada. The translated questionnaire was given to two SLPs and two Linguists for content validation and to assess the cultural and linguistic equivalency. 65 participants (34 males and 31 females) were diagnosed with voice disorders, and 65 participants who were age and gender-matched and had healthy voices were administered the Kannada version of VFHQ (VFHQ-K).

RESULTS

The results showed that the VFHQ-K had good test-retest reliability, internal consistency, and known groups' discriminative validity. The cut-off point of the VFHQ-K was equal to 26.50, indicating that the VFHQ-K had acceptable discrimination between the patients with and without dysphonia.

CONCLUSION

VFHQ-K is a valid, reliable, and sensitive questionnaire to assess the emotional, physical, and functional effects of vocal fatigue in the Kannada-speaking population.

Singing more, singing harsher: occurrence of nonlinear phenomena in a primate' song

Nonlinear phenomena (NLP) in animal vocalizations arise from irregularities in the oscillation of the vocal folds. Various non-mutually exclusive hypotheses have been put forward to explain the occurrence of NLP, from adaptive to physiological ones. Non-human primates often display NLP in their vocalizations, yet the communicative role of these features, if any, is still unclear. We here investigate the occurrence of NLP in the song of a singing primate, the indri (Indri indri), testing for the effect of sex, age, season, and duration of the vocal display on their emission. Our results show that NLP occurrence in indri depends on phonation, i.e., the cumulative duration of all the units emitted by an individual, and that NLP have higher probability to be emitted in the later stages of the song, probably due to the fatigue indris may experience while singing. Furthermore, NLP happen earlier in the vocal display of adult females than in that of the adult males, and this is probably due to the fact that fatigue occurs earlier in the former because of a greater contribution within the song. Our findings suggest, therefore, that indris may be subjected to physiological constraints during the singing process which may impair the production of harmonic sounds. However, indris may still benefit from emitting NLP by strengthening the loudness of their signals for better advertising their presence to the neighboring conspecific groups.

Vocal Fatigue, Dysphonia Risk, and Associated Factors in Male Brazilian Evangelical Pastors

OBJECTIVES

To identify the presence of vocal fatigue and dysphonia risk in evangelical pastors and to verify associations of vocal fatigue with dysphonia risk and other factors.

STUDY DESIGN

Cross-sectional observational study.

METHODS

Ninety-two evangelical pastors, professionally active, answered an on-line questionnaire divided in three steps. The first step consisted of data for the characterization of the sample. In the second stage, participants answered the vocal fatigue index questionnaire (VFI). Finally, they answered to the Brazilian Dysphonia Screening tool. A descriptive analysis of the data was performed along with Spearman's Correlation test between VFI factors and the three possible decision rules for the Brazilian Dysphonia Screening tool. A linear regression model was designed to verify predictive variables associated with the outcome "vocal fatigue".

RESULTS

Ninety male individuals were included. The average sample was off the threshold scores of tiredness and voice impairment, physical discomfort, improvement of voice symptoms with rest, and the total score of VFI. The dysphonia risk was low and was weakly negatively correlated with the improvement of voice symptoms with rest. The linear regression indicated that the presence of a current vocal complaint increases about four points in the VFI.

CONCLUSION

Evangelical pastors present symptomatology of vocal fatigue and low risk for dysphonia. However, the greater the improvement of voice symptoms with rest, the lower the risk for dysphonia. Furthermore, the presence of a current vocal complaint is associated with increased symptoms of vocal fatigue.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Patient Profiling: Determining the Effects of Patient Factors on Vocal Fatigue

OBJECTIVES

The phenomenon of vocal fatigue and the types of patients that are at greatest risk for vocal fatigue are not fully understood. The goal was to investigate patient profiles such as voice disorder type, demographics (age and gender), singing identity, interoceptive awareness, and psychosocial impacts on the severity of vocal fatigue.

STUDY DESIGN

Prospective cohort study.

METHODS

Ninety-five subjects with voice disorders were asked to complete Part 1 of the Vocal Fatigue Index (VFI-Part1), the Voice Handicap Index-10 (VHI-10), and the Multidimensional Assessment of Interoceptive Awareness, version 2 (MAIA-2). The effects of voice disorder type (structural, neurological, functional), psychosocial impact, age, gender, self-reported singing identity, and interoceptive awareness on self-perceived vocal fatigue (VFI-Part1) were determined using multivariate linear regression.

RESULTS

Vocal fatigue had a significant psychosocial impact on patients with voice disorders, as measured by the VHI-10 (P < 0.001). However, there were no significant effects of vocal fatigue across any of the three voice disorder types (P's >0.05). Age (P = 0.220), gender (P = 0.430), and self-identified singing experience (P = 0.360) also did not have significant effects on vocal fatigue. Additionally, there were no significant relationships between interoceptive awareness MAIA-2 sum scores (P = 0.056) or any of the MAIA-2 sub-scores (P's > 0.05) and vocal fatigue severity (VFI-Part1).

CONCLUSION

Vocal fatigue has a significant psychosocial impact on patients with voice disorders. However, patient profiles, including voice disorder type, patient age, gender, singing identity, and level of interoceptive awareness do not appear to play a major role in vocal fatigue symptom reporting. These findings suggest caution should be exercised when attributing patient profiles to vocal fatigue presentation and severity. Studying pathophysiological mechanisms underlying vocal fatigue may help better distinguish unconscious bias in patient profiling from the etiology and severity of vocal fatigue.

Relationship Between Vocal Fatigue Index and Acoustic Voice Scales in Patients With Coronavirus Infection

OBJECTIVES

The voice quality of patients with Coronavirus Disease 2019 (COVID-19) seems to be affected due to lower and upper respiratory involvement. Patient-based voice assessment scales are important clinical measures to diagnose voice disorders and monitor treatment outcomes in COVID-19 patients. This study compared vocal fatigue between COVID-19 patients and those with normal voices. Furthermore, the relationship between vocal fatigue and acoustic voice parameters of COVID-19 patients was evaluated.

METHODS

This cross-sectional study enrolled 30 laboratory-confirmed patients with COVID-19 (18 males and 12 females) and 30 healthy individuals with normal voices (14 males and 16 females) to compare their respiratory or phonatory parameters. The Persian versions of the Consensus Auditory Perceptual Evaluation of Voice (CAPE-V) and the vocal fatigue index (VFI) were conducted before and after reading the text. The Jitter, shimmer, maximum phonation time, and harmonic-to-noise ratio (HNR) were analyzed by Praat software based on the recorded voices of CAPE-V tasks. The acoustic assessment and VFI questionnaire results were compared between COVID-19 patients and the control group.

RESULTS

There were significant differences between COVID-19 patients and their healthy counterparts in all VFI subscales (P < 0.001). Moreover, after reading the text, we found significant differences between the two groups regarding Jitter, shimmer, and HNR of /a/ and /i/ vowels (P < 0.05). Our findings also indicated a significant correlation between symptom improvement with rest and acoustic parameters in all tasks, except the Jitter of /a/ before reading the text.

CONCLUSION

Patients with COVID-19 showed significantly more vocal fatigue than people with normal voices after reading the text. Moreover, there was a significant relationship between Jitter, shimmer, and HNR and the tiredness of voice and physical discomfort subscales of VFI.

Comprehensive Index of Vocal Fatigue (CIVF): Development and Clinical Validation

OBJECTIVES

In this study, we sought to investigate whether auditory-perceptual and acoustic measures change after a passage-reading task and to develop a multidimensional index of performance fatigue in voice disorders. The clinical usefulness and cut-off scores of the newly developed index were also explored.

METHODS

A total of 150 patients (age = 35.65 ± 11.44 years) with voice disorders and 100 healthy controls (age = 35.04 ± 11.26 years) were enrolled in the study. Overall severity (OS) and acoustic measures of sentence samples were obtained before and after a passage-reading task and compared between the two positions. Acoustic features included cepstral peak prominence (CPP), σCPP, L/H spectral ratio (SR), and σSR. Using the changes (Δ) in those acoustic measures and the scores of the Vocal Fatigue Index (VFI), a predictive model of the ΔOS was established. The clinical cut-off point of the index was also identified.

RESULTS

For the patient group, OS was higher, but CPP and σCPP were lower for the rear position (after reading the passage) compared to the front position (before reading the passage). A significant portion (adjusted R² = 77.7%) of the ΔOS was predicted by ΔCPP, tiredness score of the VFI, ΔσCPP, ΔσSR, and ΔSR. The area under the curve of the newly developed index was .864 (sensitivity, 78.67%; specificity, 78.00%), and the index's criterion was >2.6489.

CONCLUSIONS

The newly developed Comprehensive Index of Vocal Fatigue (CIVF) can quantify vocal fatigue in voice disorders, reflecting both acoustic and auditory perceptual changes after a passage-reading task. Further studies should explore the responsiveness of the CIVF and the impact of related factors on the CIVF in various voice disorders.

Interoception, Voice Symptom Reporting, and Voice Disorders

OBJECTIVES

Interoception may play a role in how individuals perceive their voice disorder. The first objective of this study was to investigate relationships between interoception and voice disorder class (functional, structural, neurological). The second objective was to determine relationships between interoception and voice-related outcome measures between patients with functional voice and upper airway disorders and typical voice users. The third objective was to determine whether patients with primary muscle tension dysphonia (a type of functional voice disorder) had different levels of interoceptive awareness than typical voice users.

STUDY DESIGN

Prospective cohort study.

METHODS

One hundred subjects with voice disorders completed the multidimensional assessment of interoceptive awareness-2 (MAIA-2). Voice diagnosis and singing experience were also acquired from each patient's medical chart. Voice handicap (VHI-10) and Part 1 of the vocal fatigue index (VFI-Part1) scores were obtained from patients diagnosed with functional voice and upper airway disorders. MAIA-2, VHI-10, VFI-Part1, and singing experience were also obtained from 25 typical voice users. Multivariable linear regression models were used to assess the association between response variables and voice disorder class, adjusting for singing experience, gender, and age.

RESULTS

There were no significant group differences between voice disorder class (functional, structural, neurological) after adjusting for multiple comparisons. Participants with functional voice and upper airway disorders who scored significantly higher on the VHI-10 and VFI-Part1 had lower Attention Regulation sub-scores on the MAIA-2 (P's<0.05). Patients with primary muscle tension dysphonia scored significantly lower on the Emotional Awareness MAIA-2 subscale than typical voice users (P=0.005).

CONCLUSION

Patients with functional voice disorders with lower capabilities to attend to body sensations may score higher on voice-related patient-reported outcome measures, like the VHI-10 and VFI-Part1. Patients with primary muscle tension dysphonia may also have lower capabilities in processing their body sensations than typical voice users.

Is Cepstral Peak Prominence a Measure of Vocal Fatigue in Temple Priests: A Pilot Study

PURPOSE

Considering cepstral analysis of voice as a measure of overall severity of dysphonia, we tried to investigate if these measures could be considered as a metric of vocal fatigue as well. Since voice quality changes are seen as a result of vocal fatigue, we wanted to find out if there were any correlations between the cepstral measures, vocal fatigue symptoms, and auditory perceptual evaluation of voice in professional voice users.

METHOD

The pilot study was conducted on 10 temple priests belonging to the Krishna Consciousness Movement. We conducted a pre-post voice evaluation, which included recording voices before the beginning of any temple preaching in the morning and after all the preaching sessions in the evening. The priests also filled in the Vocal Fatigue Index (VFI) questionnaire twice (morning and evening), and all the voice samples were analyzed for GRBAS (Grade, Roughness, Breathiness, Asthenia, and Strain voice quality) rating by speech language pathologists with voice expertise. Correlations were obtained between the acoustic measures, VFI responses, and auditory perceptual evaluations.

RESULT

The findings of our pilot study didn't show any correlations between the cepstral measures and the questionnaire responses or with the perceptual ratings. However, the cepstral measures were slightly higher for evening recordings than the morning recordings. Our participants did not experience or perceive any voice symptoms or vocal fatigue.

CONCLUSION

Despite more than 10 hours of voice use per day for over 10 years, our participants did not experience any voice symptoms or vocal fatigue. This finding indicates that there may be diverse reasonings and opinions about the occurrence of voice problems in various professional voice users. This is particularly because the participants' responses to vocal fatigue symptoms had more of a psychological explanation (faith, self-power, etc.) rather than any physiological changes in the vocal apparatus.

Comparison of Vocal Fatigue in Speech Therapists With Other Rehabilitation Therapists

INTRODUCTION

Voice, as one of the most important communication tools in humans, can cause many problems in a person's daily life if it is damaged. One type of voice complaint is vocal fatigue, which is common among people who use their voices a lot. Rehabilitation therapists may be more vulnerable to a variety of vocal disorders and complaints due to extensive voice use and long-term relationships with clients. The aim of this study is to investigate and compare vocal fatigue among therapists in Ahvaz rehabilitation fields.

METHOD

This cross-sectional, descriptive-analytical study was performed on 100 therapists in Ahvaz rehabilitation fields. For this purpose, the Persian version of the vocal fatigue index questionnaire has been used. One Way Anova parametric tests were used to compare target variables. The relationship between vocal fatigue and work experience and working hours per day was calculated using Spearman correlation coefficient.

RESULTS

A comparison of the scores of the vocal fatigue index in the rehabilitation therapists showed that there was a significant difference between the therapists scores in the field of speech therapy and the therapists scores in other fields (P < 0.05).

CONCLUSION

Due to the nature of rehabilitation fields and the use of voice during daily interactions with different clients, especially clients with special disabilities, the possibility of voice disorders and complaints in this population should be considered. Therefore, providing the necessary training for voice care and voice health of this population should be noted in order to prevent voice disorders and complaints.

Physiologic Voice Rehabilitation Based on Water Resistance Therapy With Connected Speech in Subjects With Vocal Fatigue

PURPOSE

The present study aimed to assess the effectiveness of a physiologic voice therapy program based on water resistance therapy (WRT) exercises including connected speech in a group of subjects with voice complaints (vocal effort and fatigue).

METHODS

Twenty-four participants with behavioral dysphonia were randomly assigned to one of two treatment groups: (1) voice treatment with WRT plus vocal hygiene program (n = 12), and (2) vocal hygiene program only (n = 12). Laryngoscopic assessment was performed in all subjects. Before and after voice therapy, participants underwent aerodynamic and electroglottographic assessment. The Voice Handicap Index (VHI) and self-assessment of resonant voice were also performed. The treatment included six voice therapy sessions. For the experimental group, the exercises consisted of a sequence of seven phonatory tasks performed with two different voice training devices (PocketVox and MaskVox). Comparison for all variables was performed between experimental group and control group.

RESULTS

Significant differences were found for experimental group for VHI physical subscale, and self-perceived resonant voice when comparing pre-post conditions. A strong negative correlation between self-perceived resonant voice and VHI physical sub-score was also reported. No significant differences were found for instrumented variables.

CONCLUSION

Physiologic voice therapy based on WRT exercises including connected speech seems to be an effective tool to improve self-perceived voice in subjects diagnosed with voice complaints. Apparently, changes are more prone to occur in perceptual variables related with physical discomfort associate with voice production. A reduction in phonatory effort and perceptual aspects of vocal fatigue are the main improvements.

Self-reported Vocal Demands, Perceptions, and Knowledge of Occupational Voice Users in South Africa

OBJECTIVES

The study aimed to describe daily vocal demands, perceptions and knowledge as reported by occupational voice users.

STUDY DESIGN

A descriptive, cross-sectional research design was employed.

METHODS

A survey on vocal demands, perceptions and knowledge was distributed to 102 occupational voice users via a snowball sampling technique.

RESULTS

Slightly more than half of the participants (55%) reported using their voice for work 36.5 hours a week on average (SD = 15.5, range: 33-40). Participants reported that, on average, their daily voice use is 6.3 hours (SD = 2.7) for work and the majority (81%) reported a decrease in voice quality after work; Three-quarters (75%) also reported vocal fatigue at the end of day. Approximately one-third (33%) reported being exposed to environments where they are expected to shout, scream or cheer loudly. More than half of the participants (61%) reported that they have previously received vocal health education but 40% reported that they felt this training was insufficient. High vocal demands are significantly correlated to an increase in perceived vocal handicap rs = 0.242; (P = 0.018), tiredness of voice rs = 0.270; (P = 0.008), physical discomfort rs = 0.217; (P = 0.038) as well as how occupational voice users experience improvement of symptoms with rest rs = -0.356 (P < 0.001). Other risk factors highlighted by occupational voice users are the ingestion of liquid caffeine, alcohol, and carbonated drinks, smoking or the presence of chronic cough, chronic laryngitis, and gastroesophageal reflux disease.

CONCLUSIONS

Occupational voice users are subjected to high daily vocal demands that can be seen to be linked to vocal fatigue, changes in voice quality and vocal symptoms experienced. It is essential that occupational voice users as well as treating clinicians are aware of certain significant predictors of both vocal handicap and vocal fatigue. These findings provide insights for developing strategies for training and cultivating vocal health consciousness and preventive voice care initiatives that focus on occupational voice users in South Africa.

Detecting Vocal Fatigue with Neural Embeddings

Vocal fatigue refers to the feeling of tiredness and weakness of voice due to extended utilization. This paper investigates the effectiveness of neural embeddings for the detection of vocal fatigue. We compare x-vectors, ECAPA-TDNN, and wav2vec 2.0 embeddings on a corpus of academic spoken English. Low-dimensional mappings of the data reveal that neural embeddings capture information about the change in vocal characteristics of a speaker during prolonged voice usage. We show that vocal fatigue can be reliably predicted using all three types of neural embeddings after 40 minutes of continuous speaking when temporal smoothing and normalization are applied to the extracted embeddings. We employ support vector machines for classification and achieve accuracy scores of 81% using x-vectors, 85% using ECAPA-TDNN embeddings, and 82% using wav2vec 2.0 embeddings as input features. We obtain an accuracy score of 76%, when the trained system is applied to a different speaker and recording environment without any adaptation.

The Effects of Room Acoustics on Self-reported Vocal Fatigue: A Systematic Review

PURPOSE

The main objective of the present systematic review is to quantify the relationship between the room acoustics and self-reported vocal fatigue.

METHODS

A comprehensive literature search and systematic review were conducted using PubMed/MEDLINE, Science Direct, Web of Science, EBSCO, and Scopus databases. Two inclusion criteria were defined: (1) description of a relationship between the room acoustics and self-reported vocal fatigue; and (2) reporting of raw data and/or a statistic of the association between the variables. Risk of bias in the included studies was assessed via the Quality Assessment Tool for Quantitative Studies Effective Public Health Practice Project. The occurrences and frequencies of the most common parameters in the literature are presented, and a quantitative summary of their relationships is reported.

RESULTS

In total, 12 publications met the inclusion criteria. The most relevant measures of self-reported vocal fatigue were the Vocal Fatigue Index (n = 3), Vocal Signs and Symptoms Questionnaire (n = 1), and vocal fatigue visual analog scales (n = 2). The most relevant room acoustic parameters include noise conditions (n = 6) and reverberation time (n = 2). The relationships between the room acoustic parameters and self-reported vocal fatigue are quantified and reported while maintaining the concepts stated in the original articles and outlining their similarities.

CONCLUSION

Overall, background noise and reverberation time were determined to be the most significant independent variables associated with self-reported vocal fatigue. A primary limitation of the evidence was inconsistent measures of self-reported vocal fatigue.

A Voice Rehabilitation Protocol With the Semioccluded Ventilation Mask in Subjects With Symptoms of Vocal Fatigue and Phonatory Effort

PURPOSE

The present study was designed to assess the efficacy of a six-session physiologic voice therapy program with the semioccluded ventilation mask (SOVM) in a group of subjects with voice complaints (vocal effort and fatigue).

METHODS

Thirty-four participants with functional dysphonia were randomly assigned to one of two treatment groups: (1) voice treatment with physiologic voice therapy plus vocal hygiene program (n = 17), and (2) vocal hygiene program only (n = 17). Laryngoscopic assessment was performed in all subjects to confirm laryngeal diagnosis. Before and after voice therapy, participants underwent aerodynamic assessment. The Voice Handicap Index (VHI), Vocal Tract Discomfort Scale (VTDS), and self-assessment of resonant voice were also performed. The treatment included six voice therapy sessions. For the experimental group, the exercises consisted of a sequence of seven phonatory tasks performed with the SOVM. Comparison for all variables was performed between experimental group and control group.

RESULTS

Statistical analysis showed significant improvements for experimental group for VHI (decrease), VTDS (decrease), and self-perception of resonant voice quality (increase). Significant decrease for experimental group was observed in subglottic pressure and phonation threshold pressure.

CONCLUSION

Physiologic voice therapy based on the SOVM with connected speech exercises seems to be an effective tool to improve voice in subjects diagnosed with voice complaints. Apparently, improvements are reflected in both subjective and objective outcomes. A reduction in phonatory effort and perceptual aspects of vocal fatigue are the main subjective improvements. A decrease in air pressure-related variables seems to be the most important objective change after voice therapy.

Listening to Video Game Voices: A Call for Action for Research into the Vocal Health of Video Game Voice Actors

Video game voice actors (VGVAs) are a professional voice user (PVU) population whose occupation relies on their ability to reliably deliver extremes in vocal performance. In their work VGVAs are required to perform solo for extended durations, producing highly complex character performances that not only include extremes of vocal parameters and qualities but also highly demanding vocal acts (ie, screaming, singing) within those voice archetypes. Based on the vocal demands of their work and current understandings of occupational voice disorder, it is reasonable to consider that VGVAs may be at increased risk of vocal fatigue, injury, and disorder, as manifestations of occupational disease. This risk is of primary concern to VGVAs who recently organized industrial action to highlight their concerns regarding vocal health within their industry. As a group that is not well represented within voice research, there is little literature currently available to inform clinical support of the population. Due to the unique nature of VGVA work and the highly specific nature of occupational voice use among PVUs, we cannot necessarily generalize research from other populations to VGVAs. As such, research utilising frameworks designed to capture the complexity of voice use, demands on the voice, and experiences of its use are required to support the concerns of the population. This paper introduces VGVAs as an emerging PVU population, describes the concerns of this population within the context of current understandings of vocal fatigue, occupational voice problems and PVU populations, and details the approaches required in the development of research into the population.

Linguistic and Cultural Adaptation and Validation of the Vocal Fatigue Index into Polish

OBJECTIVE

The purpose of the present study was the cross-cultural and linguistic adaptation and validation of the Vocal Fatigue Index (VFI) in the Polish language.

METHODS

The Vocal Fatigue Index was adapted into Polish and was administered to 323 subjects (216 with voice disorders, and 107 without voice disorders). One hundred and four participants with voice disorders completed the VFI a second time to evaluate test-retest reliability. VFI was assessed for internal consistency, test-retest reliability, discriminant validity, criterion validity, and sensitivity and specificity.

RESULTS

The Polish VFI exhibited satisfactory psychometric properties. A high Cronbach's alpha coefficient for the three factors (α=0.971 for Factor 1, α=0.929 for Factor 2, α=0.930 for Factor 3) was obtained. Significantly higher scores were revealed in subjects with voice disorders (48.88±11.73 [mean±SD]) in comparison with vocally healthy subjects (12.25±6.75 [mean±SD]) in the total VFI score as well as in the three factors (all P-values < 0.01). The best cut-off for VFI Total Score was set at a 32.5 score with sensitivity of 0.931 and specificity of 0.991.

CONCLUSIONS

The translated version of the VFI is a valid and reliable tool for identifying vocal fatigue symptoms in the Polish-speaking population.

Vocal Fatigue in School Teachers and It's Relation to the Acoustic analysis of Voice

Voice disorders are thought to be one of the major occupational hazards of school teaching. There is a need to study the prevalence of vocal fatigue in school teachers as it is unknown in Indian population and its awareness is at a very basic level. We aim to investigate percentage of school teachers reporting vocal fatigue and to find if there is any relationship between vocal fatigue and acoustic voice parameters. A total of 100 subjects (50-males and 50-females) in the age range of 25-35 years participated in the study. Voice Sample was obtained from the subject using a digital tape recorder and was analyzed in Visi pitch and Dr.Speech softwares. The sample was taken twice in a day, that is, before teaching and after teaching. The mean values obtained on all the questions of the vocal fatigue questionnaire show a significant increase in mean values on all the questions at post teaching ratings. Results revealed a statistically significant difference in pre and post teaching values of F0 and shimmer in males. In females, statistical significant difference was obtained in Noise to Harmonic Ratio in /u/ production. No significant correlation between acoustic parameters and overall vocal fatigue was found except for Noise to Harmonic ratio in females for /u/.

Efficacy of Voice Therapy With Acapella Choice ® Device in Subjects With Vocal Fatigue Delivered Via Telepractice

PURPOSE

The present study aimed at assessing the effectiveness of remote voice therapy (telepractice) implemented with Acapella Choice device in subjects with vocal fatigue.

METHODS

Thirty participants with vocal fatigue were randomly assigned to one of two treatment groups: (1) voice treatment with acapella Choice device plus vocal hygiene program (n=15), and (2) voice treatment with Water resistance therapy plus vocal hygiene program (n=15). Laryngoscopic assessment was conducted in all subjects to confirm diagnosis. Before and after voice therapy, participants underwent self-assessment of voice. Vocal Fatigue Index (VFI), Voice Handicap Index (VHI), and Vocal tract discomfort scale (VTDS) were used. Treatment period included six voice therapy sessions within 3 weeks, with a frequency of two therapy sessions per week. Each session lasted 30 minutes. For both groups, exercises consisted of a sequence of nine phonatory tasks performed with Acapella Choice (experimental group) and WRT (control group). Comparison for all variables were performed between experimental group and control group.

RESULTS

Significant improvements were found when comparing Pre and Post measures for both groups. No significant differences were found when comparing Acapella Choice group and WRT group.

CONCLUSION

Remote physiologic voice therapy with Acapella Choice device and water resistance therapy seem to be both effective to improve voice in subjects diagnosed with vocal fatigue. No differences should be expected between these therapeutic protocols when treating patients with vocal fatigue. Moreover, both are effective at reducing tiredness of voice, voice avoidance, physical discomfort associated with voicing, subjective perception of sensory discomfort in throat, and reduction of physical, emotional, and functional impact of voice problems.

A comparative and correlational study of the Vocal Fatigue Index (VFI) and the Voice Fatigue Handicap Questionnaire (VFHQ) in individuals with and without voice disorders

OBJECTIVES

The aim of this study was to examine the difference and correlation between the Vocal Fatigue Index (VFI) and the Voice Fatigue Handicap Questionnaire (VFHQ) among individuals with and without voice disorders.

STUDY DESIGN

Observational study.

METHODS

This study was performed from June to December 2021. A total of 308 people were enrolled, including 72 men and 236 women. Questionnaire scores were obtained for both the VFI and the VFHQ. The Mann-Whitney U test and Spearman correlational analysis were used to analyze the data.

RESULTS

Of the 308 participants, 186 had a voice disorder and 122 did not. The most common voice disorders were chronic laryngitis and vocal fold polyps. The VFI and VFHQ scores differed between groups with and without voice disorders and between men and women. The VFHQ total score correlated significantly with all subscale scores of the VFHQ and with the VFI factor scores.

CONCLUSIONS

People with voice disorders have significantly worse voice-related quality of life and more severe vocal fatigue symptoms than those without. The scores on the VFI and VFHQ correlate significantly.

The Effect of Upper Airway Ailments on Teachers' Experience of Vocal Fatigue

BACKGROUND

Teachers have been found to have a higher than normal risk to develop voice disorders. One common symptom of voice problems among teachers is the report and occurrence of vocal fatigue, often associated with different individual, physical, environmental, and professional factors.

AIM

The aim of this study was to provide insight into the potential effect of sinus infections, laryngitis, colds, seasonal allergies, and reflux on reported vocal fatigue, as quantified by the Vocal Fatigue Index (VFI).

METHOD

An exploratory cross-sectional design was implemented via an online survey sent by email to teachers of kindergarten through 12th-grade in 31 states throughout the USA.

RESULT

The main result of this study was that teachers with self-reported reflux and seasonal allergies had statistically significant higher scores on VFI Factor 1 (performance), VFI Factor 2 (pain), and VFI Factor 3 (recovery) when compared to those without self-reported reflux and seasonal allergies.

CONCLUSIONS

It may be likely that an individuals' change in reported vocal fatigue over time may be also associated with health-related factors, such as reflux and seasonal allergies rather than just changes in voice production. These associated factors should be considered and potentially controlled for in future research and clinical practice surrounding teachers' experience of vocal fatigue.

Multiparametric analysis of voice following prolonged voice use and voice rest in teachers: evidence from discriminant analysis

PURPOSE

Even though recent investigations have used multiparametric protocol, the set of robust parameters in determining the effects of vocal fatigue and voice rest in teachers is not clear. The first objective of the study was to document the impact of prolonged voice use and voice rest on the subjective and objective voice parameters among Indian secondary school teachers. The second objective was to determine the set voice parameters sensitive to vocal changes resulting from continuous voice use and voice rest.

METHOD

The study included 15 male and 15 female secondary school teachers with a clinically normal voice and no history of voice disorders. Phonation samples were recorded in three different conditions, i.e., condition 1 (before voice use), condition 2 (following voice use), and condition 3 (following voice rest). The vocal Fatigue Index (version 2) was administered before the voice recordings in all three conditions. The objective parameters, namely fundamental frequency, range of fundamental frequency, jitter (%), shimmer (%), harmonic to noise ratio, and smoothened cepstral peak prominence, were extracted.

RESULTS

Results revealed that fundamental frequency, jitter, shimmer, Harmonic to noise ratio, and smoothened cepstral peak prominence were significantly different across the three conditions. The discriminant analysis revealed that only three parameters classified 98.3% of samples accurately between the three conditions.

CONCLUSION

Further research on the correlation between the other subjective and the objective parameters of voice after vocal fatigue would provide more penetrating and ample in-depth insights into the assessment and quantification of vocal fatigue.

Comparing the Effects of Self-Generated and Platform-Generated Whole Body Vibration on Vocal Fatigue

OBJECTIVES

A whole body vibration platform using vertical oscillation has been shown to be efficacious in reducing vocal fatigue in adults. This study aimed to investigate whether this platform-generated whole body vibration was unique in reducing vocal fatigue by comparing it with self-generated whole body vibration.

METHODS

Twenty-four female adults (mean age = 23.96 years) were randomly assigned to one of the following three groups: a machine-generated whole body vibration group (N = 8), a self-generated whole body vibration group (N = 8), and a placebo vocal resting group (N = 8). All participants performed a karaoke singing task for at least 95 minutes. Each participant received 10 minutes of platform-generated vibration, self-vibration, or sham localised vibration (placebo group with basically voice rest only), according to their group allocation. Vocal function ability, measured by the highest fundamental frequency produced, and a self-reported vocal fatigue score were evaluated at three time points: baseline (prefatigue), after the singing task (post-fatigue) and post-vibration.

RESULTS

The study revealed that machine-generated whole body vibration was significantly better at improving vocal fatigue than self-generated whole body vibration or voice rest.

CONCLUSION

The findings support previous research that machine-generated whole body vibration is effective in reducing vocal fatigue. The non-significant results of self-generated whole body vibration in terms of relieving vocal fatigue suggest that inadequate vibration frequency or amplitude together with leg muscle fatigue may have been the main factor of ineffectiveness.

The German Restructured Vocal Fatigue Index and Characteristics of Dysphonic and Vocally Healthy Populations

OBJECTIVE

The Vocal Fatigue Index (VFI), a 19-item psychometric self-report questionnaire, enables individuals with vocal fatigue (VF) to be identified and their complaints to be characterized. The purpose of this study was to improve the German-language version (VFI-G) and to evaluate further vocal fatigue-related characteristics of dysphonic and control populations.

METHODS

The VFI-G was restructured by replacing the three factors that structured the original: (1) tiredness of voice and voice avoidance; (2) physical discomfort; and (3) improvement of symptoms with rest, with two clusters developed on the basis of the results of a factor analysis by Nanjundeswaran et al. (2019). The two new clusters are: (1) tiredness and avoidance plus physical discomfort; and (2) symptom improvement through rest. One hundred one (101) individuals with voice disorders and 100 vocally healthy controls from a previous study that cross-validated the VFI-G participated in this study. In order to assess the validity of our newly adjusted VFI-G, independent samples t test, receiver operating characteristic curve, likelihood ratios and the Youden Index were calculated. The association of the two VF clusters with subject characteristics such as age, sex, type of voice disorder, and level of vocal usage was also analyzed using either a Pearson correlation or a one-way ANOVA for each of the two populations.

RESULTS

Significantly higher scores were obtained in voice-disordered subjects in both clusters (all P values < 0.001) than in healthy-voice subjects. The threshold for cluster 1 of the VFI-G was determined as ≥17.5 (74.3% sensitivity and 88.0% specificity). The results of cluster 2 are identical to that of factor 3 of the previous cross-validation study of the VFI-G. Most subject characteristics show no significant association with cluster 1 of the VFI-G, but cluster 2 seems to be moderately associated with age, type of voice disorder and level of vocal usage in the dysphonic population.

CONCLUSIONS

The restructured VFI-G showed improved validity and can be recommended for use in the assessment of VF. Cluster 2 is also moderately associated with several vocal fatigue-related subject characteristics of the dysphonic population.

Vocal resistance among choir singers

PURPOSE

The purpose of the present study was to compare the voice of choir singers before and after 60 min of singing and after an absolute rest.

METHODS

Twenty-one female choir singers aged on average 26.59 years, with experience in choir singing of at least one year were instructed to emit the vowel /a/ before and after singing and after a vocal rest of 30 min for an analysis of acoustic measures, and for the evaluation of their tactile-kinesthetic self-perception. Vocal warm-up was performed for 10 min. The participants were instructed to sing the "Ave Verum" music continuously for 60 min.

RESULTS

f0 (p = 0.0001) and Flo (p = 0.0002) increased after the singing test and were reduced after the vocal rest, in contrast to Fhi (p = 0.001), which continued to be increased compared to the pre-test measure even after the vocal rest. The vAm parameter (p = 0.05) was reduced after continuous singing and rest. All self-evaluation symptoms increased after the continuous singing task and were reduced after the 30 min rest, except for complaints of low voice, pain when swallowing and cough/throat clearing.

CONCLUSION

60 min of continuous use of the singing voice induced signs of vocal fatigue with an increase in f0, with improvement of symptoms and a reduction of f0 occurring after 30 min of vocal rest.

Differences on Voice Acoustic Parameters between Colombian College Professors with and without Vocal Fatigue

AIM

To determine which acoustic parameters may be associated with vocal fatigue among college professors in Bogotá-Colombia.

METHOD

This was a cross-sectional study including 27 voice samples of college professors.

RESULTS

A gender analysis showed that mean fundamental frequency increased significantly among men and women who reported vocal fatigue compared with the those without fatigue (138.2Hz vs 122.3Hz for males; and 228.7Hz vs 188.9Hz for females; Mann-Whitney U test P value <0.01). Participants with vocal fatigue demonstrated a significantly decreased standard deviation of vocal sound pressure level compared to participants without vocal fatigue (8.7 dB vs 10.2 dB; Mann-Whitney U test P value <0.01). For the males in our sample, fundamental frequency had fair discriminatory value for vocal fatigue (area under the curve = 0.7). Sensitivity and specificity were moderate at a cut-off of 125 Hz (0.7 and 0.6 respectively). For females in this sample, the discriminatory value of fundamental frequency was slightly higher (area under the curve = 0.8). At a cut-off of 200 Hz, sensitivity was high (0.9) and specificity were moderate (0.7).

CONCLUSION

In conclusion, the fundamental frequencies and standard deviations of vocal sound pressure level are good indicators of and may be used to identify college professors with vocal fatigue. Clinically, voice clinicians may aim to train their clients to produce speech with a higher variation of "intensity" in order to avoid vocal fatigue.

Relations between Creaky Voice and Vocal Symptoms of Fatigue

BACKGROUND

The use of a creaky voice in speech has become more common. Laryngeal findings relate creaky voice with strong adductive tension in the glottis, and thus it may be expected to be related to an increased risk of vocal fatigue.

METHODS

The present study investigated the relation of creaky voice use and vocal symptoms in 104 Finnish female university students (mean age 24.3 years, SD 6.3 years). They had no known pathology of voice or hearing. The participants were recorded while reading aloud a text of approximately 40 s in duration. They also filled in a questionnaire consisting of the Voice Handicap Index (VHI, translation in Finnish), and half of them also answered questions about the frequency and severity of symptoms of vocal fatigue. The samples were perceptually analysed for the amount of creakiness and strain by a speech therapist and a voice trainer.

RESULTS

The interrater reliability of the listeners was acceptable (Pearson's χ2 = 100.159, p = 0.000 for creak; χ2 = 69.199, p = 0.000 for strain). Neither creakiness nor strain correlated with vocal symptoms. Participants with a low and a high amount of creakiness or strain did not differ from each other in terms of vocal symptoms or VHI scores. Symptoms' total score correlated with VHI total score and total scores of VHI's physical subscale. Creakiness and strain correlated positively with each other (r = 0.40, p = 0.000).

CONCLUSION

No significant relations were found between creakiness or strain and vocal symptoms in this sample of university students.

The Effect of Superficial Hydration, With or Without Systemic Hydration, on Voice Quality in Future Female Professional Singers

OBJECTIVE

The aim of this study was to describe the effect of superficial hydration, with or without systemic hydration, on voice quality in future female professional singers by assessing acoustic and perceptual parameters of voice production as well as symptoms of vocal fatigue.

STUDY DESIGN

This is an experimental design study.

METHODS

A study was performed on a sample of 24 female voice majors to ascertain the effect of superficial hydration, with or without systemic hydration, on acoustic parameters and perception of vocal fatigue. The study replicated a prior study by van Wyk et al (2016) with some modifications; we looked at the effect of both systemic and superficial hydration independently and together on voice quality and vocal fatigue. Acoustic measurements including GRBASI, jitter, shimmer, F₀ MPT, frequency min and max, intensity min and max, and dysphonia severity index were measured along with perceived vocal fatigue using the Vocal Fatigue Index.

RESULTS

A statistically significant increase in MPT values were obtained when comparing pre- and post-test results of the hypo hydrated (P = 0.015) and superficial hydration condition (P = 0.004). A significant increase in frequency min (Hz) within the hypo hydrated condition was also observed (P = 0.019). A significant increase was observed in the intensity min (dB) (P = 0.010) and F₀ min (Hz) (P = 0.002) within the combined hydration condition. Also, when superficial hydration was applied, mean shimmer % (P = 0.016), MPT (sec) (P = 0.003) and dysphonia severity index (P = 0.020) scores increased significantly in a between-group, post-test comparison. A significant reduction in mean intensity max (dB) (P = 0.049) and intensity min (dB) (P = 0.018) was also observed.

CONCLUSIONS

This study demonstrates that the use of superficial hydration results in positive outcomes of perceptual parameters of voice quality and symptoms of vocal fatigue in future female professional singers. However, mixed results were observed regarding the acoustic parameters of voice. The superficial hydration data is compelling enough to warrant implementing in a vocal hygiene protocol for singers.

[Pretesting of the German Vocal Fatigue Index (VFI-D)-transcultural translation and cross validation]

BACKGROUND

In clinical routine, vocal fatigue is a common symptom in patients with dysphonia.

OBJECTIVE

The aim of this study was to conduct a transcultural translation of the Vocal Fatigue Index (VFI), a standardized subjective questionnaire. Furthermore, pretesting and prevalidation were performed in 20 subjects, with comparison to the Voice Handicap Index (VHI‑9i) and the Vocal Tract Discomfort Scale (VTD).

MATERIALS AND METHODS

The translation, content review, and pretest of the German Vocal Fatigue Index (VFI-D) was divided into four sections: 1. transcultural translation, 2. expert voting on comprehensibility, 3. test of comprehensibility through cognitive interviews in 15 participants, 4. pretest of the VFI‑D with cross validation compared to VHI‑9i and VTD in 20 subjects. This process corresponds to current standards for transcultural translation and adaptation of questionnaires.

RESULTS

According to expert voting and cognitive testing, the VFI‑D is correct and comprehensible (intercoder reliability κ = 0.66). The factor analysis revealed three distinguishable parts: VFI‑D part 1 correlates strongly with VHI‑9i and VTD, VFI‑D part 2 with VTD only (rho ≈ 0.800 each), and VFI‑D part 3 correlates only weakly with VHI‑9i and VTD (rho ≈ 0.585). Thus, convergence and divergence validity are proven.

CONCLUSION

The first German version of the VFI‑D might be a base for further research on symptoms, causes, and treatment options in vocal fatigue. Particularly patients in voice-intensive professions may benefit.

Vocal Fold Paresis

This article discusses vocal fold paresis as a separate and distinct condition from vocal fold paralysis. The signs and symptoms of paresis may be different and less obvious than those for paralysis, so this condition is often misdiagnosed or underdiagnosed. Elements necessary to heighten clinical suspicion are included to assist in educating practitioners on these subtle findings. Once paresis is suspected, associated respiratory or sensory abnormalities also should be sought, because these may change the treatment plan when recognized. Utility of laryngeal electromyography is discussed along with potential treatment options for both the motor and often-present sensory symptoms.

The Effect of Pulmonary Function on the Incidence of Vocal Fatigue Among Teachers

INTRODUCTION

Females face a significantly higher risk of presenting with voice problems than males. This discrepancy has been associated with a number of differences in respiratory behavior and the physiology of the laryngeal and endocrine systems.

METHODS

In conjunction with established spirometry measures, the Vocal Fatigue Index (VFI) was used to determine (1) if there is a relationship between base pulmonary function and vocal fatigue among teachers; and (2) if that relationship is different in females from males. One hundred and twenty-two elementary and middle school teachers (96 females and 26 males) from the Jordan School District in Northern Utah participated in the study.

RESULTS

VFI factors were predictors of the outcomes of several raw spirometry measures for female participants, but the same predictive relationship was not found for male participants. Additionally, there appeared to be no relationship between VFI and spirometry measures in females when using normalized, rather than raw, spirometry metrics.

CONCLUSIONS

The results suggest that the pulmonary physiology that would result in reduced raw pulmonary function, in combination with other differences associated with gender, may lead to a greater incidence of vocal fatigue among female teachers than their male counterparts.

Cross-Cultural Adaptation and Validation of the Vocal Fatigue Index into Persian

INTRODUCTION

The aim of the present study was the cross-cultural adaptation and validation of the Vocal Fatigue Index (VFI) in Persian.

METHODS

The English version of the VFI was translated to Persian using the guidelines of International Quality of Life Assessment. Eighty participants with voice disorders and 50 healthy controls without any voice disorders completed the Persian version of the VFI. The 80 participants with voice disorders completed the VFI a second time a week from the initial completion to evaluate test-retest reliability.

RESULTS

The VFI measure demonstrated a strong internal consistency. Cronbach alpha coefficient was 0.95 for tiredness and avoidance of voice use, 0.86 for physical discomfort and 0.83 for improvement or lack thereof of symptoms with voice rest. VFI also showed a high test-retest reliability (r = 0.75-0.89).

CONCLUSIONS

The Persian version of the VFI is considered to be a valid and reliable questionnaire for identifying individuals with probable vocal fatigue. The VFI can be utilized in clinics across Iran in the assessment and treatment of individuals with vocal fatigue.

Impact Stress in Water Resistance Voice Therapy: A Physical Modeling Study

OBJECTIVES

Phonation through a tube in water is used in voice therapy. This study investigates whether this exercise may increase mechanical loading on the vocal folds.

STUDY DESIGN

This is an experimental modeling study.

METHODS

A model with three-layer silicone vocal fold replica and a plexiglass, MK Plexi, Prague vocal tract set for the articulation of vowel [u:] was used. Impact stress (IS) was measured in three conditions: for [u:] (1) without a tube, (2) with a silicon Lax Vox tube (35 cm in length, 1 cm in inner diameter) immersed 2 cm in water, and (3) with the tube immersed 10 cm in water. Subglottic pressure and airflow ranges were selected to correspond to those reported in normal human phonation.

RESULTS

Phonation threshold pressure was lower for phonation into water compared with [u:] without a tube. IS increased with the airflow rate. IS measured in the range of subglottic pressure, which corresponds to measurements in humans, was highest for vowel [u:] without a tube and lower with the tube in water.

CONCLUSIONS

Even though the model and humans cannot be directly compared, for instance due to differences in vocal tract wall properties, the results suggest that IS is not likely to increase harmfully in water resistance therapy. However, there may be other effects related to it, possibly causing symptoms of vocal fatigue (eg, increased activity in the adductors or high amplitudes of oral pressure variation probably capable of increasing stress in the vocal fold). These need to be studied further, especially for cases where the water bubbling frequency is close to the acoustical-mechanical resonance and at the same time the fundamental phonation frequency is near the first formant frequency of the system.

The Effect of Classroom Capacity on Vocal Fatigue as Quantified by the Vocal Fatigue Index

OBJECTIVE

Previous research has concluded that teachers are at a higher-than-normal risk for voice issues that can cause occupational limitations. While some risk factors have been identified, there are still many unknowns.

PATIENTS AND METHODS

A survey was distributed electronically with 506 female teacher respondents. The survey included questions to quantify three aspects of vocal fatigue as captured by the Vocal Fatigue Index (VFI): (1) general tiredness of voice (performance), (2) physical discomfort associated with voicing (pain), and (3) improvement of symptoms with rest (recovery). The effect of classroom capacity on US teachers' self-reported experience of vocal fatigue was analyzed.

RESULTS

The results indicated that a classroom's capacity significantly affected teachers' reported amounts of vocal fatigue, while a teacher's age also appeared to significantly affect the reported amount of vocal fatigue. A quadratic rather than linear effect was seen, with the largest age effect occurring at around 40-45 years in all three factors of the VFI.

CONCLUSION

Further factors which may affect vocal fatigue must be explored in future research. By understanding what increases the risk for vocal fatigue, educators and school administrators can take precautions to mitigate the occupational risk of short- and long-term vocal health issues in school teachers.

Videokymographic Visualization of Phonasthenia: A Nonorganic Voice Disorder

BACKGROUND

Phonasthenia is a voice disorder where the larynx looks essentially normal and dysphonia is not heard but felt by the patient. This study aims to use videokymography (VKG) to detect any abnormalities in the vibratory pattern in phonasthenia and to find out whether or not these abnormalities change after vocal loading.

METHODS

Thirty-seven phonasthenic patients and 31 normal subjects participated in a detailed protocol, including analysis of subjective complaints and videokymographic quasi-objective parameters (baseline) followed by loading their voices through prolonged loud reading for 45 min. A second evaluation (experimental) was done after loading.

RESULTS

Before vocal loading, patients had significantly more symptoms in all questionnaire questions and higher maximum width difference in VKG than controls. When pre- and postloading values were compared, both groups experienced more symptoms after loading (significant in most of the questions), while the pre- and post-VKG parameters did not show significant differences neither in patients nor controls. On comparing their percent change, the only statistically significant difference between the 2 groups was a greater change in the total score of the questionnaire in the control group.

CONCLUSION

Patients had more vocal fatigue symptoms and more amplitude asymmetry between left and right vocal folds than normal subjects.

Speech Adjustments for Room Acoustics and Their Effects on Vocal Effort

OBJECTIVES

The aims of the present study are (1) to analyze the effects of the acoustical environment and the voice style on time dose (D_{t_p}) and fundamental frequency (mean f₀ and standard deviation std_f₀) while taking into account the effect of short-term vocal fatigue and (2) to predict the self-reported vocal effort from the voice acoustical parameters.

METHODS

Ten male and ten female subjects were recorded while reading a text in normal and loud styles, in three rooms-anechoic, semi-reverberant, and reverberant-with and without acrylic glass panels 0.5 m from the mouth, which increased external auditory feedback. Subjects quantified how much effort was required to speak in each condition on a visual analogue scale after each task.

RESULTS

(Aim1) In the loud style, D_{t_p}, f₀, and std_f₀ increased. The D_{t_p} was higher in the reverberant room compared to the other two rooms. Both genders tended to increase f₀ in less reverberant environments, whereas a more monotonous speech was produced in rooms with greater reverberation. All three voice parameters increased with short-term vocal fatigue. (Aim2) A model of the vocal effort to acoustic vocal parameters is proposed. The sound pressure level contributed to 66% of the variance explained by the model, followed by the f₀ (30%) and the modulation in amplitude (4%).

CONCLUSIONS

The results provide insight into how voice acoustical parameters can predict vocal effort. In particular, it increased when SPL and f₀ increased and when the amplitude voice modulation decreased.

Effects of vocal fatigue on voice parameters of Indian Teachers

Vocal fatigue is a frequently reported voicec symptom among professional voice users. Indian School teachers teach lontinuously for many hours in advene acoustical environments and are highly susceptible to vocal fatigue. The present study is the first to examine acoustic voice measures in teacher, reporting naturally induced vocal fatigue. 40 female primary school teachers (mean age =36 yearn) with varying severity of vocal fatigue participated in this studr. Voice measures of minimum and maximum fundametal frequency were obtained before and after one and a half hours of continuous teaching at the workplace. Maximum fundamental frequent was an important acoustic parameter in determining presence of weal fatigue. Most cummin perceptual sympioms include throat dryneis, discomfort and loss of voit e. The rule of vocal hygiene and warm-up in reducing vocal fatigue are considered.