Vocal fatigue in doctors: evaluation with subjective and objective acoustic parameters

Cross-Cultural Adaptation and Validation of the Vocal Fatigue Index (VFI) to Danish

OBJECTIVES

The aim was to cross-culturally adapt and validate the Vocal Fatigue Index (VFI) to Danish (DK-VFI).

STUDY DESIGN

Cross-sectional design.

METHODS

The original American English VFI was cross-culturally adapted to Danish using a forward-backward translation procedure combined with focus group interviews. The DK-VFI was distributed to 26 patients with vocal fatigue (VF) and 103 vocally healthy controls. A matched subsample based on age and sex of the control group was included. Internal consistency was determined using Cronbach's alpha and test-retest reliability was determined using Spearman's Rho as well as Wilcoxon signed-rank tests. Validity was confirmed using the Wilcoxon rank-sum test. Sensitivity and specificity were assessed using the Receiver Operating Characteristics test and the discriminative ability was determined using the Area Under the Curve (AUC) test. The original VFI consists of three factors, and cutoff values were calculated for each separate factor in the DK-VFI.

RESULTS

Minor changes were made in the phrasing of specific questions in order to appropriate the VFI to the Danish language. The internal consistency for the DK-VFI was high, with a Cronbach's alpha of α = 0.95. The results showed statistically significant differences (P < 0.05) in mean scores of the DK-VFI between patients and controls. The cutoff values between patients and controls for each separate factor were ≥11.5 for factor 1, ≥2.5 for factor 2, and ≤5.5 for factor 3. The results of the AUC analysis showed that the DK-VFI has discriminative abilities of 0.94 for factor 1, 0.92 for factor 2, and 0.82 for factor 3. Analysis of test-retest reliability showed strong reliability for the patient group and acceptable reliability for the control group.

CONCLUSION

The DK-VFI is a valid and reliable tool for identifying symptoms of VF and can sensitively discriminate people with VF from vocally healthy controls.

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.

Association Between Vocal Symptoms, Communication, Work Environment, and Sense of Coherence in Hospital Health Professionals

OBJECTIVE

This study aimed to associate the presence of vocal symptoms with sociodemographic and occupational data, work environment self-perception, oral communication wearing a face mask, and the sense of coherence (SOC).

METHOD

This cross-sectional analytical observational study included 66 health professionals from a Brazilian hospital. They answered an online questionnaire on sociodemographic aspects, self-perception of the physical work environment, and oral communication at work. The Voice Symptom Scale (VoiSS) and Sense of Coherence Scale (SOC-13) were also applied. The significance level was set at 5% for the statistical analysis.

RESULTS

The self-perception of vocal symptoms was 62%. Professionals who considered the noise in their work environment unsatisfactory had more vocal symptoms (P = 0.005), especially in the limitation (P = 0.013) and physical (P = 0.028) domains of the VoiSS. Professionals with higher self-perceived vocal symptoms also reported incoordination between breathing, speech, and articulation (P = 0.041) and self-perceived difficulty being heard with a protective mask (P = 0.033). Professionals with a higher self-perceived score in the limitation domain of the VoiSS also had a higher self-perceived effort to speak with a mask (P = 0.035) and a higher self-perception that other people find it difficult to hear them with a face mask (P = 0.050). There was a weak negative correlation between VoiSS and SOC (P < 0.05) and between its domains (P < 0.05).

CONCLUSION

Self-perception of voice symptoms is high among health professionals in a Brazilian public hospital. The presence of these symptoms is related to the perception of a noisy work environment and communication difficulties due to the use of a face mask. The lower the ability to cope with stressful situations, the larger the presence of voice symptoms among health professionals.

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.

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

PURPOSE

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

METHODS

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

RESULTS AND CONCLUSION

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

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.

What are the Symptoms that Characterize the Clinical Condition of Vocal Fatigue? A Scoping Review and Meta-Analysis

INTRODUCTION

Vocal fatigue is a clinical manifestation associated with a perception of negative vocal adjustment. It is related to the increase in the sensation of excessive effort when speaking and the lack of conditioning of the muscles and structures that involve vocal production. Because it has a complex and multifactorial diagnosis, there is still no consensus on the symptoms most commonly found in this clinical condition.

OBJECTIVE

To review and analyze the symptoms that characterize the clinical condition of vocal fatigue.

METHODS

This study consists of a scoping review carried out in the Cochrane Library, Embase, Lilacs, and Medline databases. Observational studies or clinical trials from the last 10 years. Studies with participants younger than 18 years of age were excluded; as well as research that did not describe symptoms of vocal fatigue or that presented vocal fatigue as a symptom; studies with patients with neurological, psychiatric, syndromic conditions, or head and neck cancer. The Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies NHLBI-NIH scale was used to assess the methodological quality of selected observational studies and the PEDro scale for the analysis of experimental studies. The steps were performed by three blinded evaluators. Subsequently, meta-analyses of global means were executed for each factor under study; a comparison of the difference in the mean score for each factor between exposed and unexposed; a comparison of the difference in the average score, among non-professional voice users, for each factor between exposed and unexposed.

RESULTS

In the searches performed, 956 articles were found and 29 articles were selected according to the eligibility criteria. Of these, 93.11% of the studies were observational and 6.89% were clinical trials. Regarding the gender and age group of the study samples, women aged between 30 and 45 years were predominant. As for the occupational use of voice, 68.97% of the samples were composed of professional voice users and 31.03% of non-professional voice users, with most professional voice users being teachers and non-professional voice users, individuals with dysphonia or vocal complaint. To assess vocal fatigue symptoms, 28 studies used the Vocal Fatigue Index (VFI) protocol, and only one study used another assessment protocol, Self-Administered Voice Rating. All studies were classified as regular, according to the scale used. As for the meta-analyses performed, the mean scores of the VFI factors were higher among professional voice users when compared to non-professional voice users and higher in dysphonic individuals compared to non-dysphonic individuals.

CONCLUSION

The vocal fatigue symptoms found in this review were common in the populations of professional voice users and non-professional voice users and dysphonic and non-dysphonic individuals. These symptoms were related to vocal recovery after rest, physical discomfort, and restricted vocal use.

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.

Potential Biophysiological Mechanisms Underlying Vocal Demands and Vocal Fatigue

Patients with complaint of vocal fatigue have perceptual, acoustic, and aerodynamic outcomes that are heterogeneous in nature. One reason may be due to different underlying biophysiological mechanisms that lead to these heterogeneous clinical presentations. Five potential mechanisms are proposed: neuromuscular, metabolic, vocal tissue, afferent, and central neural. Analytical frameworks and study designs to study these mechanisms are also addressed. A better understanding of biophysiological mechanisms of vocal fatigue can improve precision of therapeutic approaches. It can also help shift management from symptom-based to etiology-focused approaches for vocal fatigue.

Laying the Groundwork to Study the Heterogeneous Nature of Vocal Fatigue

Vocal fatigue has remained an elusive construct-despite its significant impact on communication, vocation, and quality of life. Current frameworks define vocal fatigue in the context of vocal demands and vocal demand-responses. However, the impact of factors like individuals' baseline vocal fitness and perception of the demand are not well understood. What is also not well understood are the effects of specific vocal demand ingredients on an individual's vocal demand responses. Furthermore, current outcome measures utilized to capture vocal fatigue lack sensitivity and underlying mechanisms are poorly understood. These gaps have led to inconclusive next steps in how to best define, assess, monitor, and manage vocal fatigue. A conceptual framework is needed to study and better understand vocal fatigue constructs. Such a framework should consider the individual's baseline physiology, psychology, key vocal demand ingredients, and biophysiological mechanisms underlying demand responses. The objective of this paper is to help the reader better understand the complex and heterogeneous nature of vocal fatigue and its impact on reliable assessment and monitoring. Future studies will require better elucidation of vocal demand ingredients, will need more sensitive vocal demand response measures, and will need to take in to account an individual's baseline physiology and psychological factors.