The Impact of a Vocal Loading Task on Voice Characteristics of Female Speakers With Benign Vocal Fold Lesions

OBJECTIVES

To examine the effect of a vocal loading task on measures of vocal structure and function in females with benign vocal fold lesions (BVFLs) and determine if change is observed in voice and lesion characteristics.

STUDY DESIGN

Prospective cohort study.

METHODS

Twenty-eight (n = 28) female subjects with phonotraumatic BVFLs completed a vocal loading task of 30 minutes of reading aloud at 75-85 dBA. Multidimensional voice evaluation was completed pre- and post-load, including audio and videostroboscopy recordings and images for expert perceptual ratings and acoustic and aerodynamic evaluation. Subjects also scored themselves using a 10 cm visual analogue scale for Perceived Phonatory Effort, and completed the Evaluation of Ability to Voice Easily, a 12 item self-report scale of current perceived speaking voice function. An exploratory rather than confirmatory approach to data analysis was adopted. The direction and magnitude of the change scores (pre- to post-load) for each individual, across a wide variety of instrumental and self-report measures, were assessed against a Minimal Clinically Important Difference criteria.

RESULTS

Observations of change and the direction of change in vocal response of individuals with BVFLs to 30 minutes of loud vocal load was variable. Minimal to no change was noted for participants pre- to post-load as rated perceptually, for auditory and videostroboscopy samples. For most instrumental measures, change was shown for many participants including an overall improvement in aerodynamic and acoustic measures of function and efficiency post-load for 20 participants (77%) and decline in function for 4 participants (15%). Self-reported effort and vocal function post-load was multidirectional with similar numbers of participants reporting no change, improved function or a decline.

CONCLUSION

Subjects with BVFLs demonstrate change in vocal function following 30 minutes of vocal load. While this change can be variable and multidirectional, overall improvement was observed in instrumental measures of function and efficiency for most participants. Some participants perceived this change to be an increase in effort, some a reduction in effort and some perceived no change. Improved vocal function despite relative lesion stability can seemingly occur after loading in some pathological voices.

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.

The Influence of Age, Gender, Health-Related Behaviors, and Other Factors on Occupationally Relevant Health Complaints of Singers

OBJECTIVES

Professional singers' careers are usually associated with health-relevant factors that they themselves may or may not be able to influence. We have therefore investigated the effect of modifiable health-related behaviors and non-modifiable factors on singers' occupational health.

METHODS

In an explorative, questionnaire-based study, self-reported, occupationally relevant health complaints and behaviors, along with singer-specific characteristics, were surveyed from 349 professional singers and voice teachers (116 men, 233 women; age 18-73 years) and the influence of age, gender, duration of daily and lifelong singing, voice category, and health-related behaviors (smoking, alcohol consumption, physical activity) on occupationally relevant health complaints were analyzed using bi- and multivariate statistical methods.

RESULTS

Singers reported less risky alcohol consumption (5.4% versus ≈15%) and smoking (15.5% versus 29.7%) than the general population, and too little physical activity was described in two thirds of both populations. After controlling for multiple testing, no effect was found for these behaviors, the time spent singing daily, gender, or voice categories on singers' complaints. Health complaints were significantly fewer for males (P < .001) and older women and were reported more frequently for higher-pitched male voices, a trend not found in females.

CONCLUSION

Singers seem to smoke and drink less than members of the general population. These factors did not affect their complaints. Female singers described more work-related health complaints than males, a finding that corresponds to women in the general population. Older singers reported fewer complaints than younger singers, possibly because of selection effects or older singers acquiring strategies to avoid health-damaging behavior.

High and Wide: An In Silico Investigation of Frequency, Intensity, and Vibrato Effects on Widely Applied Acoustic Voice Perturbation and Noise Measures

OBJECTIVES

This in silico study explored the effects of a wide range of fundamental frequency (fo), source-spectrum tilt (SST), and vibrato extent (VE) on commonly used frequency and amplitude perturbation and noise measures.

METHOD

Using 53 synthesized tones produced in Madde, the effects of stepwise increases in fo, intensity (modeled by decreasing SST), and VE on the PRAAT parameters jitter % (local), relative average perturbation (RAP) %, shimmer % (local), amplitude perturbation quotient 3 (APQ3) %, and harmonics-to-noise ratio (HNR) dB were investigated. A secondary experiment was conducted to determine whether any fo effects on jitter, RAP, shimmer, APQ3, and HNR were stable. A total of 10 sinewaves were synthesized in Sopran from 100 to 1000 Hz using formant frequencies for /a/, /i/, and /u/-like vowels, respectively. All effects were statistically assessed with Kendall's tau-b and partial correlation.

RESULTS

Increasing fo resulted in an overall increase in jitter, RAP, shimmer, and APQ3 values, respectively (P < 0.01). Oscillations of the data across the explored fo range were observed in all measurement outputs. In the Sopran tests, the oscillatory pattern seen in the Madde fo condition remained and showed differences between vowel conditions. Increasing intensity (decreasing SST) led to reduced pitch and amplitude perturbation and HNR (P < 0.05). Increasing VE led to lower HNR and an almost linear increase of all other measures (P < 0.05).

CONCLUSION

These novel data offer a controlled demonstration for the behavior of jitter (local) %, RAP %, shimmer (local) %, APQ3 %, and HNR (dB) when varying fo, SST, and VE in synthesized tones. Since humans will vary in all of these aspects in spoken language and vowel phonation, researchers should take potential resonance-harmonics type effects into account when comparing intersubject or preintervention and postintervention data using these measures.

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.

Relationships Among Personality, Daily Speaking Voice Use, and Phonotrauma in Adult Female Singers

PURPOSE

This study sought to determine whether personality traits related to extraversion and impulsivity are more strongly associated with singers with nodules compared to vocally healthy singers and to understand the relationship between personality and the types of daily speaking voice use.

METHOD

Weeklong ambulatory voice recordings and personality inventories were obtained for 47 female singers with nodules and 47 vocally healthy female singers. Paired t tests investigated trait differences between groups. Relationships between traits and weeklong speaking voice measures (vocal dose, sound pressure level [SPL], neck surface acceleration magnitude [NSAM], fundamental frequency, cepstral peak prominence [CPP], and the ratio of the first two harmonic magnitudes [H 1 -H 2]) were examined using pairwise Pearson r coefficients. Multiple regressions were performed to estimate voice parameters that correlated with two or more traits.

RESULTS

Singers with nodules scored higher on the Social Potency scale (reflecting a tendency toward social dominance) and lower on the Control scale (reflecting impulsivity) compared to the vocally healthy singers. In vocally healthy singers, vocal dose measures were positively correlated with a combination of Wellbeing (i.e., happiness) and Social Potency, mean SPL was positively correlated with Wellbeing, SPL variability was positively correlated with Social Potency and negatively with Harm Avoidance, and CPP mean was positively correlated with Wellbeing. Singers with nodules had a negative correlation between NSAM skewness and Social Potency. Both groups had negative correlations between H 1 -H 2 mean and Social Potency and Social Closeness.

CONCLUSIONS

Singers with nodules are more socially dominant and impulsive than vocally healthy singers. Personality traits are related to daily speaking voice use, particularly in vocally healthy singers. Individuals with higher levels of traits related to happiness and social dominance and lower Harm Avoidance tended to speak more, with higher laryngeal forces, with more SPL variability, and with more pressed glottal closure, which could increase risk of phonotrauma.

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.

Differences Between Female Singers With Phonotrauma and Vocally Healthy Matched Controls in Singing and Speaking Voice Use During 1 Week of Ambulatory Monitoring

Purpose Previous ambulatory voice monitoring studies have included many singers and have combined speech and singing in the analyses. This study applied a singing classifier to the ambulatory recordings of singers with phonotrauma and healthy controls to determine if analyzing speech and singing separately would reveal voice use differences that could provide new insights into the etiology and pathophysiology of phonotrauma in this at-risk population. Method Forty-two female singers with phonotrauma (vocal fold nodules or polyps) and 42 healthy matched controls were monitored using an ambulatory voice monitor. Weeklong statistics (average, standard deviation, skewness, kurtosis) for sound pressure level (SPL), fundamental frequency, cepstral peak prominence, the magnitude ratio of the first two harmonics (H₁-H₂ ), and three vocal dose measures were computed from the neck surface acceleration signal and separated into singing and speech using a singing classifier. Results Mixed analysis of variance models found expected differences between singing and speech in each voice parameter, except SPL kurtosis. SPL skewness, SPL kurtosis, and all H₁-H₂ distributional parameters differentiated patients and controls when singing and speech were combined. Interaction effects were found in H₁-H₂ kurtosis and all vocal dose measures. Patients had significantly higher vocal doses in speech compared to controls. Conclusions Consistent with prior work, the pathophysiology of phonotrauma in singers is characterized by more abrupt/complete glottal closure (decreased mean and variation for H₁-H₂ ) and increased laryngeal forces (negatively skewed SPL distribution) during phonation. Application of a singing classifier to weeklong data revealed that singers with phonotrauma spent more time speaking on a weekly basis, but not more time singing, compared to controls. Results are used as a basis for hypothesizing about the role of speaking voice in the etiology of phonotraumatic vocal hyperfunction in singers.

Frequency Range Measures in Carnatic Singers

BACKGROUND

Frequency range measures in singers reflect their physiological capacity, vocal flexibility, training effects, strengths, and limitations in singing. Since this information is vital for pedagogic and clinical purposes, this study aimed to measure the frequency range in Carnatic singers while singing different aspects of the vocal music.

METHOD

Practice task (gliding from lowest to highest note) and performance task (singing a song with vocal ornaments) were recorded from 55 trained Carnatic singers (40 females and 15 males). The auditorily verified portions of various vocal ornaments in Carnatic singing (such as aalapanai, pallavi, anupallavi, charanam, and niraval) were coded as separate tokens. A total of 385 tokens were analyzed using PRAAT software for estimating frequency range in semitones during practice task (SFR_prac) and performance task (SFR_perf). Descriptive, ANOVA, Tukey HSD, independent t, and Mann-Whitney U were used for statistical analysis.

RESULTS

SFR_prac was higher than SFR_perf in Carnatic singers. During practice, singers explored their physiological range to improve their vocal ability. However, during performance they tend to maintain a comfortable singing range to have a flawless rendition. Aalapanai (most creative portion) had the highest frequency range (females: 22.96 ST, males: 24.57 ST) than other types of vocal ornaments in performance signing. Practice frequency range (SFR_prac) and performance frequency range (SFR_perf) were not statistically different across male and female singers.

CONCLUSION

This study described the frequency range measures in various aspects and nuances of Carnatic singing. Its clinical and pedagogic importance are discussed.

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.