Vocal resistance among choir singers

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.

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.

Voice Quality of Choir Singers and the Effect of a Performance on the Voice

BACKGROUND

The voice use of choir singers is understudied despite the imbalance of high vocal demands versus low vocal education, and consequently increased risk for voice problems. Also, there is a lack of information on the effects of a performance on choristers' voices. Available studies included performances of at least one hour. To date, no studies investigated the effects of a choir performance with a duration resembling vocal warm-ups.

PURPOSE

The first purpose of this study was to determine the voice quality, capacities, symptoms and voice-related quality of life of choir singers. Secondly, the effect of a short choir performance, resembling warm-up duration (15 minutes), on the choristers' voices was investigated.

METHODS

A randomized controlled trial was used. Thirty adult choir singers (25 women, 5 men; mean age: 32 years) were assigned randomly to an experimental group or a control group. Participants in the experimental group sung in choir for 15 minutes immediately after their pre voice assessment, whereas the control group was instructed to have standard voice use (one-on-one conversation with the investigator, no singing) across that time span. A second voice assessment was repeated afterwards.

RESULTS

The choir singers showed excellent voice quality and capacities with mean scores on the Dysphonia Severity Index and Acoustic Voice Quality Index of 7.5 and 2.0, respectively. Auditory-perceptually, the mean grade score was 5/100 corresponding with a normal to mildly deviant voice quality. Patient-reported outcome measures showed mean deviant scores, indicating a considerable singing voice handicap. The choir singers seem vulnerable for stress with a high occurrence rate of 76.7% (23/30). Compared with the control group, the Dysphonia Severity Index significantly improved, whereas the self-perceived presence of vocal fatigue and complaints increased after 15 minutes of choir singing. Fundamental frequency increased in both groups, being more outspoken in the experimental group.

CONCLUSIONS

Choir singers show excellent voice quality and capacities, that further improve after a short choir performance of 15 minutes. Vocal fatigue and complaints, on the other hand, already increased after that short time span. Realizing that vocal load is much higher in real-life rehearsals, competitions and performances, choristers deserve and need a qualitative voice training and a strict follow-up. Future research should focus on effective vocal warm-up and cool-down programs for this population.

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.