Perspectives on the Impact on Vocal Function of Heavy Vocal Load Among Working Professional Music Theater Performers

Towards Automated Vocal Mode Classification in Healthy Singing Voice-An XGBoost Decision Tree-Based Machine Learning Classifier

Auditory-perceptual assessment is widely used in clinical and pedagogical practice for speech and singing voice, yet several studies have shown poor intra- and inter-rater reliability in both clinical and singing voice contexts. Recent advances in artificial intelligence and machine learning offer models for automated classification and have demonstrated discriminatory power in both pathological and healthy voice. This study develops and tests an XGBoost decision tree based machine learning classifier to develop automated vocal mode classification in healthy singing voice. Classification models trained on mel-frequency cepstrum coefficients, MFCC-Zero-Time Windowing, glottal features, voice quality features, and α-ratios demonstrated 92% average F1-score accuracy in distinguishing metallic and non-metallic singing for male singers and 87% average F1-score for female singers. The model distinguished vocal modes with 70% and 69% average F1-score for male and female samples, respectively. Model performance was compared to human auditory-perceptual assessments of 64 corresponding samples performed by 41 professional singers. The model performed with approximating or subpar performance to human assessors on task-matched problems. The XGBoost gains observed across tested features reveal that the most important attributes for the tested classification problems were MFCCs and α-ratios between high and low frequency energy, with models trained on only these features achieving performance not statistically significantly different from the best tested models. The best automated models in this study do not yet match human auditory-perceptual discrimination but improve on previously reported F1-average accuracies in automated classification in singing voice.

Independence of Vocal Load From Vocal Pathology Across Singing Genres

OBJECTIVE

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

STUDY DESIGN

Cross sectional survey.

METHODS/DESIGN

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

RESULTS

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

CONCLUSION

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

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.

Extreme Vocals-A Retrospective Longitudinal study of Vocal Health in 20 Professional Singers Performing and Teaching Rough Vocal Effects

BACKGROUND

Rough vocal effects, extreme, or extended vocal techniques to sound intentionally hoarse or rough are an integral part of many genres and styles, and research has recently demonstrated the involvement of supraglottic narrowing and vibrations to produce such sounds. The vocal health of singing with rough vocal effects is poorly documented, especially in a longitudinal manner, while much vocal pedagogy continuously treats the sounds as harming to or dangerous for the vocal mechanism.

OBJECTIVE

To longitudinally investigate the vocal health of professional singers who perform the five rough-sounding vocal effects Distortion, Growl, Grunt, Rattle, and Creaking as part of their singing and teaching.

METHODS

Twenty singers underwent nasoendoscopic examination, filled in SVHI questionnaires, and were assessed by GRBAS with a 14-year interval in a retrospective longitudinal study (from 2007 to 2021). Endoscopic materials were assessed by Reflux Finding Score and a hybrid version of the Stroboscopy Rating Scale.

RESULTS

Singers presented at initiation of study with an average SVHI of 9.2 (±9), which decreased at time of follow up 14 years later to an average of 5.12 (±6). Laryngeal assessments (RFS and SRS) revealed low averages at initiation of study as well as at conclusion of the study with only small fluctuations in averages, with findings mainly relating to arytenoid asymmetry.

CONCLUSION

The participating singers perform and teach rough vocal effects continually and present with healthy laryngeal mechanisms and within-normal SVHI and GRBAS scores. The findings suggest that controlled supraglottic narrowing and techniques to allow for supraglottic structures to engage in vibration as an additional noise source can be performed sustainable and in a healthy manner if performed with correct vocal technique.

Voice Disorders in the Workplace: A Scoping Review

OBJECTIVE

Occupational voice users (OVU) are at risk for developing voice disorders (VD). Otolaryngologists need to advocate for workplace accommodations for these patients. The objective of this study was to assess the literature on VDs in the workplace and to describe how results may guide the Otolaryngologist.

DATA SOURCES

EBSCO, PubMed, Google Scholar, UBC libraries, and SpringerLink databases.

REVIEW METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analysis extension for Scoping Reviews protocol was used to conduct a scoping review from inception to December 30, 2019. Oxford Levels of Evidence were used to assess the quality of included studies. Common themes and types of accommodations and barriers were explored. This study was registered with the Open Science Framework Open Source for Collaboration in Scientific Research (10.17605/OSF.IO/RYDVN).

RESULTS

One hundred and ninety-three abstracts were screened; 32 studies met inclusion criteria. Oxford Levels of Evidence ranged from 3 to 5. Eight overarching themes were identified: prevalence of VDs among OVUs; identifying risk factors for VDs; raising awareness of VDs medico-legally, politically; the education and treatment of VDs, the importance of diagnosing VDs; measuring the impact of VDs on work productivity; identifying perceived barriers to integration into the workplace; and calculating the economic costs of VDs. VDs affect workplace productivity and have associated absenteeism, medical, and economic costs. Increased awareness and education on the risk factors for VD development can assist with prevention, early diagnosis, and treatment. Accommodations and barriers are discussed.

CONCLUSION

There is emerging literature on VDs in the workplace. A multitude of VDs exist with varying pathologies, associated barriers, and implications for functioning within the workplace. Otolaryngologists play a unique role in diagnosing voice disorders and defining and facilitating workplace accommodations.

Choral Conductors Vocal Loading in Rehearsal Simulation Conditions

OBJECTIVES

Choir conductors represent a profession with an intensive vocal load. The present study aims to investigate the impact of 40 minutes vocal loading tasks on fundamental frequency (F0), jitter (Jitt), shimmer (Shim), median cepstral peak prominence (CPPs), and CPPs standard deviation in specific acoustic conditions.

METHOD

Eighteen amateur choir conductors (13 female, five male) participated in the study. The vocal loading experiment was organized in rooms where each conductor usually had choir rehearsals. The vocal loading experiment included vocal warm-up, singing, and loud reading. The STIPA test signal provided the background noise with 60 dBA @ 1m during the singing and reading tasks. The F0, Jitt, Shim, CPPs, and CPPs SD were extracted before and after vocal loading by the Vocal Holter Med (VHM) device. Additionally, Acoustic Voice Quality Index (AVQI) was estimated for participants, and all of them completed the Voice Handicap Index-30 (VHI-30) and the Singing Voice Handicap Index (SVHI). Finally, reverberation time (T30) was measured in each rehearsal room.

RESULTS

A statistically significant decrease of CPPs SD by 0.1 dB was observed in male conductors. Associations between CPPs SD and VHI-30 (r = 0.789, P = 0.001) were found in female conductors, and between Jitt and SVHI (r = 0.9, P = 0.037) in male conductors. Female conductors with higher total score of SVHI demonstrated increase of postloading F0 (r = 0.612, P = 0.026).

CONCLUSIONS

Forty-minute vocal loading tasks that included warm-up, intensive singing, and loud reading did not significantly impact vocal parameters in female and male conductors. In addition, the rehearsal room volume and length of reverberation time did not affect obtained vocal parameters after vocal loading.

Dysphonia Risk Screening Protocol for Musical Theatre Actors: a preliminary study

PURPOSE

To propose the Dysphonia Risk Screening Protocol for Musical Theatre Actors (DRSP-MTA), to verify its applicability in association with the General Dysphonia Risk Screening Protocol (G-DRSP), to correlate the final scores of both, and these with the total risk score, and to compare the risk of dysphonia measured in musical theater actors with and without vocal complaint.

METHODS

An observational cross-sectional study with 34 musical theater actors, adults, of both genders, with and without vocal complaints and regardless of whether they are professionals or students. The questionnaires were applied individually. Statistical analysis made it possible to verify the correlation between the dysphonia risk scores and to compare the groups with and without vocal complaint.

RESULTS

Most of the participants were male, young adults, professional actors and without vocal complaint. There was a high risk of dysphonia, evidenced by the application of G-DRSP, with means scores compatible with values found in individuals with dysphonia, and reinforced by the indices found with DRSP-MTA application. There was a moderate and directly proportional correlation between the two questionnaire scores; and a correlation of both with the total risk score. Higher G-DRSP scores were observed in the vocal complaint group.

CONCLUSION

DRSP-MTA was feasible and easy to apply and was positively correlated with the total score and G-DRSP score. A high risk of dysphonia was evidenced in individuals with vocal complaints. Although the specific DRSP-MTA score did not differentiate musical theatre actors with and without vocal complaints, the G-DRSP score and the total risk score performed such differentiation.

Vocal Quality, Symptoms, and Habits in Musical Theater Actors

PURPOSE

The purpose of this study was to measure and compare the voice characteristics and vocal complaints and habits of musical theater actors and musical theater students.

METHOD

Thirty participants were included in the study, 18 musical theater students and 12 professional musical theater actors. Vocal quality was measured by the multiparameter indices Dysphonia Severity Index (DSI) and Acoustic Voice Quality Index (AVQI). A perceptual evaluation of the speaking voice was performed using the GRBASI scale. All participants completed the Voice Handicap Index (VHI), the VHI adapted to the singing voice, the Vocal Tract Discomfort (VTD) Scale and the Corporal Pain Scale.

RESULTS

Excellent scores for DSI (resp. 7.3, 7.1) and AVQI (resp. 2.6, 2.5) were found in the musical theater actors and students. All participants reported at least two symptoms of VTD and the mean scores for the VHI adapted to the singing voice were located in the clinical zone. Musical theater students reported significantly more VTD and pain symptoms compared to the professionals. No significant differences in perceptual and objective voice characteristics were found between musical theater actors and students. A higher presence of vocal misuse and stress in the students was observed.

CONCLUSION

Musical theater students and actors are elite vocal performers with comparable excellent objective vocal measures (DSI, AVQI). In both groups, an increased number of VTD and complaints of the singing voice were reported. Especially students were vulnerable for stress, vocal misuse, VTD, and pain symptoms. The findings suggest that musical theater actors are a risk group for developing voice disorders requiring multidimensional voice assessment and voice care.

Vocal Quality After a Performance in Actors Compared to Dancers

STATE OF THE ART

Theater actors are a high risk group for developing voice disorders.

AIMS

The first purpose of this study was to examine and compare the objective and subjective vocal quality between professional theater actors, non-professional theater actors and a control group of professional dancers. Secondly, the impact of one theater performance on the objective and subjective vocal quality was investigated within and between the groups. It is hypothesized that actors will experience vocal fatigue and a deteriorated vocal quality compared with dancers as a result of the vocal load during the performance. Dancers will face more general fatigue and smaller vocal changes due to the impact of a performance including stress, decompensation and physical fatigue.

METHODS

Recordings of 27 professional actors, 19 non-professional actors and 16 professional dancers were collected before and after a performance using the PRAAT software. Voice samples included sustained vowel phonation, continuous speech, aerodynamic measurements and voice range profile. Both Acoustic Voice Quality Index and Dysphonia Severity Index were computed. For auditory-perceptual evaluations the GRBASI scale was used. Several questionnaires were completed pre and post performance to capture vocal risk factors.

RESULTS

Vocal quality between groups showed lower fundamental frequency (f_o) values (female), larger fundamental frequency (female) and intensity ranges and a longer maximum phonation time (female) in professional actors compared to non-professionals. Professional dancers showed higher Acoustic Voice Quality Index values compared to non-professional actors. Dysphonia Severity Index, Voice Handicap Index, Vocal Tract Discomfort Scale and GRBASI results did not differ between groups at the baseline. Both objective measurements and questionnaires did not show significantly different results post performance. Questionnaires revealed poor vocal habits in professional actors.

CONCLUSION

Professional actors have better vocal capacities than non-professionals. Dancers' vocal quality is worse than actors. The results show no impact of one performance on the vocal quality in theater actors and dancers. The long-term impact of performing, however, is subject for further research.

Immediate Effects of a Semi-Occluded Water Resistance Ventilation Mask on Objective and Subjective Vocal Outcomes in Musical Theater Students

Background Traditional semi-occluded vocal tract exercises (SOVTEs) are restricted to single-phoneme tasks due to the semi-occlusion at the mouth, which hinders full articulation, continuous speech, and singing. Innovative SOVTEs should overcome this limitation by creating the semi-occlusion outside the oral cavity. Purpose The purpose of this study was to investigate the immediate effects of a semi-occluded water resistance ventilation mask, which allows for continuous speech and singing, on objective (voice range, multiparametric voice quality indices) and subjective (auditory-perceptual, self-report) vocal outcomes in musical theater students. Method A pre-/posttest randomized controlled trial was used. Twenty-four musical theater students (16 women and eight men, with a mean age of 21 years) were randomly assigned into a study group and a control group. The study group received a vocal warm-up session with the innovative water resistance ventilation mask (tube attached to the mask "outside" the mouth), whereas the control group received the traditional water resistance approach (tube "inside" the mouth). Both sessions lasted 30 min and were similar with respect to vocal demand tasks. A multidimensional voice assessment including objective and subjective outcomes was performed pre- and posttraining by an assessor blinded to group allocation. Results The Dysphonia Severity Index significantly and similarly increased (improved) in both the study and control groups, whereas the Acoustic Voice Quality Index solely decreased (improved) in the control group. The intensity range significantly decreased (worsened) and the semitone range significantly increased (improved) in the study group, whereas no differences in voice range profile were found in the control group. Auditory-perceptually, a more strenuous speaking voice was noticed after the use of the traditional water resistance approach. The subjects perceived both SOVTEs as comfortable vocal warm-up exercises that decrease the amount of effort during speaking and singing, with a slight preference for the water resistance ventilation mask. Conclusions Both the innovative water resistance ventilation mask and the traditional water resistance exercise seem effective vocal warm-up exercises for musical theater students. The additional articulatory freedom of the mask might increase the phonatory comfort and the practical implementation of SOVTEs in the daily vocal warm-up of (future) elite vocal performers. The hypothesis of a higher transfer to continuous speech or singing in the mask condition has not been supported by the current study. Larger scale investigation and longer term follow-up studies are needed to confirm these preliminary results. Supplemental Material https://doi.org/10.23641/asha.11991549.

Amateur Music Theatre Singers' Perceptions of their Current Singing Voice Function

PURPOSE

The primary aim of this study was to investigate amateur music theatre singers (MTS)' perceptions of their current singing voice function according to evaluation of ability to sing easily (EASE) scores while involved in a musical theatre production, to determine if scores were influenced by demographic or voice-related factors and to compare EASE scores of amateur MTS and previously published professional MTS.

METHOD

Amateur singers were recruited through the Townsville Choral Society during the preproduction of Les Misérables. A total of 51 amateur MTS completed an online questionnaire including the EASE scale and a supplementary demographic questionnaire. Nonparametric statistical analyses were conducted.

RESULTS

Three singers reported they had a voice problem at the time they completed the questionnaire. The EASE did not detect significant differences in perceived vocal function among the singers according to demographic (age and gender) and voice-related characteristics. The amateur cohort reported lower current voice-use demands, such as current vocal load and number of shows over past week, than the previously described professional MTS and no significant differences were found between the two cohorts in the median EASE scores.

CONCLUSIONS

The results of this study supported both the overall validity of the EASE scale and its use with amateur MTS. In addition, the findings suggest the value of future research investigating the potential use of the EASE for broader clinical application with other population groups.

Cross-Cultural Adaptation and Validation of the Evaluation of the Ability to Sing Easily (EASE) for Kannada-Speaking Carnatic Classical Singers

OBJECTIVE

The present study aimed to cross-culturally adapt and validate the Evaluation of the Ability to Sing Easily (EASE) into Kannada for the benefit of Carnatic classical singers.

METHODS

Following a standard translation procedure, the original English version was translated to develop a prefinal EASE-K version. This was further field-tested on 12 Carnatic singers to obtain the final EASE-K version. Upon validating the same on 104 Carnatic singers, intercorrelation between EASE-K subscales- Vocal Fatigue (VF) and Pathologic Risk Indicators (PRI) were assessed using the Spearman correlation coefficient. The internal consistency of the subscales was obtained based on the Cronbach's alpha coefficient. Nonparametric tests were carried out to study the effect of age and gender on EASE-K subscales. Further, the raw scores of the English version were compared to the EASE-K.

RESULTS

Spearman correlation coefficient indicated a statistically significant positive correlation (P < .01) between the two subscales (r = .745). Each scale showed good internal consistency (Cronbach's alpha was .84). Test-retest reliability carried on 12 singers indicated an excellent reliability for the subscales. Nonparametric tests indicated no significant effect of age and gender on the subscales of EASE-K (P > .05). Comparison across the original and EASE-K revealed significant differences for both VF (P = .02) and PRI (P = .00) subscales.

CONCLUSIONS

Current findings indicate that EASE-K is a reliable and valid tool that can be used to document the subtle changes in voice in healthy Carnatic classical singers. Further, the current tool can be used to study the effect of vocal loading across different singing styles.

Equivalencia cultural de la versión Chilena del Evaluation of Ability to Sing Easily: EASE

RESUMEN Objetivo: Adaptar lingüística y culturalmente el protocolo australiano de voz cantada Evaluation of Ability to Sing Easily (EASE) al español chileno. Método: Fue realizada la traducción al español chileno del EASE y posteriormente la retrotraducción; ambas fueron revisadas por un comité compuesto por 4 fonoaudiólogos quienes crearon la primera versión en español chileno (EASE-CL). El EASE-CL está compuesto, al igual que el original, por 22 ítems que se contestan de acuerdo con una escala de Likert de frecuencia, a la que, durante la adaptación, se le sumó la alternativa “no aplicable” para poder identificar las consignas no comprendidas o inapropiadas para el vocabulario de los cantantes chilenos. Esta versión se aplicó a 21 cantantes profesionales de la región de Valparaíso. Durante esta aplicación no existieron sugerencias para el cambio de alguna consigna. Resultado: El EASE-CL refleja la versión original del inglés, tanto en la cantidad de ítems como en dominios. Conclusión: Queda demostrada la equivalencia cultural y lingüística del protocolo EASE al español chileno, originándose la versión EASE-CL.

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

BACKGROUND

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

STUDY DESIGN

Cross sectional survey.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prevalence, Characterization, and Impact of Voice Disorders in Fado Singers

INTRODUCTION

Fado is a genre of urban folk music from Portugal characterized by some particularities. Some indictions in the study point this population of singers to be at higher risk of developing voice disorders.

AIM

This study aims to provide estimates of the prevalence of voice disorders in Fado singers, and to characterize the professional practice and the impact of voice disorders on their careers.

METHODS

This is a cross sectional study based on a self-administered questionnaire split into six parts and 55 questions.

RESULTS

A gender-balanced sample of 111 singers was achieved. Most of them recorded at least once. Winter and spring were found to be the most difficult seasons in which to sing. The overall prevalence of self-reported voice disorders was 39.6%, significantly higher in females. Almost all sought clinical guidance. Vocal fold nodules, functional dysphonia, and vocal fold polyp were the most common diagnoses. Vocal fatigue and hoarseness were the main symptoms reported. Nearly half of the singers had to cancel shows due to voice disorders.

CONCLUSION

Fado singers reveal both a relative high prevalence of voice disorders and related concerns, even though some discrepancies were found regarding other apparently similar singer populations. These results lead support the need for further investigation regarding the risk or protective factors influencing voice disorders.

The Measurement and Effects of Vocal Load in Singing Performance. How Much Singing Can a Singer Sing if a Singer Can Sing Songs?

Singing as both an art form and physical activity demands a level of health and skill fitness to meet performance demands. The determination of performance fitness relies on performers' self-evaluations of their vocal capacity for performance, based, amongst other factors, on the current vocal status and ability to manage the associated vocal load. Measurement of load and the impact on the vocal mechanism is complex and influenced by many intrinsic and extrinsic factors. Researchers have attempted to quantify vocal load effects by measuring physical impact stress on the vocal folds, self-reported perceived exertion, and/or clinical evaluation of physiologic, acoustic, or perceptual changes. Most studies have been conducted in laboratory rather than in performance contexts and studies on singers are substantially lacking. Heavy vocal load has been causally associated with the development of voice disorders, although the exact relationship and thresholds for acquiring laryngeal pathology require further elucidation, and little is also known about the development of voice disorders among singers. Further understanding of the short-term and cumulative effect on the vocal folds of performing as a singer and the nature and prevalence of voice problems among singers is crucial to the determination of appropriate prevention and therapeutic management.

Vocal Qualities in Music Theater Voice: Perceptions of Expert Pedagogues

OBJECTIVES/HYPOTHESIS

To gather qualitative descriptions of music theater vocal qualities including belt, legit, and mix from expert pedagogues to better define this voice type.

STUDY DESIGN

This is a prospective, semistructured interview.

METHODS

Twelve expert teachers from United States, United Kingdom, Asia, and Australia were interviewed by Skype and asked to identify characteristics of music theater vocal qualities including vocal production, physiology, esthetics, pitch range, and pedagogical techniques. Responses were compared with published studies on music theater voice.

RESULTS

Belt and legit were generally described as distinct sounds with differing physiological and technical requirements. Teachers were concerned that belt should be taught "safely" to minimize vocal health risks. There was consensus between teachers and published research on the physiology of the glottis and vocal tract; however, teachers were not in agreement about breathing techniques. Neither were teachers in agreement about the meaning of "mix." Most participants described belt as heavily weighted, thick folds, thyroarytenoid-dominant, or chest register; however, there was no consensus on an appropriate term. Belt substyles were named and generally categorized by weightedness or tone color. Descriptions of male belt were less clear than for female belt.

CONCLUSIONS

This survey provides an overview of expert pedagogical perspectives on the characteristics of belt, legit, and mix qualities in the music theater voice. Although teacher responses are generally in agreement with published research, there are still many controversial issues and gaps in knowledge and understanding of this vocal technique. Breathing techniques, vocal range, mix, male belt, and vocal registers require continuing investigation so that we can learn more about efficient and healthy vocal function in music theater singing.

Measuring vocal function in professional music theater singers: construct validation of the Evaluation of the Ability to Sing Easily (EASE)

OVERVIEW

Working music theater singers (MTS) typically have a heavy vocal load and little is known about their perception of vocal function. The Evaluation of the Ability to Sing Easily (EASE) was used to assess professional MTS' perceptions of current singing voice status and to compare scores across demographic and performance characteristics and to evaluate the construct validity of the EASE and its subscales (VF = Vocal Fatigue, PRI = Pathologic-Risk Indicators).

METHODS

Professional MTS (n = 284) completed an online survey including the EASE and two additional Vocal Concern (VC) items. Scores were compared across age, gender, whether currently working, role, perceived vocal load over the past 24 h and self-reported voice problem.

RESULTS

For the whole cohort, statistically significant differences were found on all subscales according to whether or not singers perceived themselves to have a voice problem (p < 0.001). Currently performing singers were significantly different from those not performing in a show on the EASE Total (p = 0.014) and VF (p = 0.002), but not for PRI and VC. In the currently performing singer group, significant differences were found for gender, role and perceived voice problem on the EASE Total and all subscales (p < 0.01). Significantly higher VF scores were recorded for singers with heavy vocal load (p = 0.01), but there were no differences on the EASE Total (p = 0.57), PRI (p = 0.19) or VC subscales (p = 0.53). Among these performing singers, no significant age differences were found for any EASE subscales.

CONCLUSIONS

These findings provide further validation of the EASE as a useful tool for measuring singers' perceptions of vocal function and suggest that the subscales should be scored separately. Future evaluation of the EASE against objective clinical assessments (e.g., videostroboscopy) is recommended.