Normative values for singing voice handicap index – systematic review and meta-analysis

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.

Population characteristics and self-assessment of speaking and singing voice in Polish contemporary commercial music singers-an exploratory, cross-sectional study

Background

The domination of the Contemporary Commercial Music (CCM) industry in music markets has led to a significant increase in the number of CCM performers. Performing in a wide variety of singing styles involves exposing CCM singers to specific risk factors potentially leading to voice problems. This, in turn, necessitates the consideration of this particular group of voice users in the Occupational Health framework. The aim of the present research was threefold. First, it sought to profile the group of Polish CCM singers. Second, it was designed to explore the prevalence of self-reported voice problems and voice quality in this population, in both speech and singing. Third, it aimed to explore the relationships between voice problems and lifetime singing involvement, occupational voice use, smoking, alcohol consumption, vocal training, and microphone use, as potential voice risk factors.

Materials and methods

The study was conducted in Poland from January 2020 to April 2023. An online survey included socio-demographic information, singing involvement characteristics, and singers' voice self-assessment. The prevalence of voice problems was assessed by the Polish versions of the Vocal Tract Discomfort Scale (VTDS) and the Singing Voice Handicap Index (SVHI). Also, a self-reported dysphonia symptoms protocol was applied. The perceived overall voice quality was assessed by a Visual Analogue Scale (VAS) of 100 mm.

Results

412 singers, 310 women and 102 men, completed the survey. Nearly half of the studied population declared lifetime singing experience over 10 years with an average daily singing time of 1 or 2 h. 283 participants received vocal training. For 11.4% of respondents, singing was the primary income source, and 42% defined their career goals as voice-related. The median scores of the VTDS were 11.00 (0-44) and 12.00 (0-40) for the Frequency and Severity subscales, respectively. The median SVHI score of 33 (0-139) was significantly higher than the normative values determined in a systematic review and meta-analysis (2018). Strong positive correlations were observed between SVHI and both VTD subscales: Frequency (r = 0.632, p < 0.001) and Severity (r = 0.611, p < 0.001). The relationships between most of the other variables studied were weak or negligible.

Conclusion

The examined CCM singers exhibited substantial diversity with regard to musical genre preferences, aspirations pertaining to singing endeavors, career affiliations, and source of income. Singing voice assessment revealed a greater degree of voice problems in the examined cohort than so far reported in the literature, based on the SVH and VTDS.

A Comparison of the Dysphonia Severity Index and Singing Voice Handicap Index Between Trained and Untrained Male Iranian Traditional Singers

OBJECTIVES

This study aimed to compare trained and untrained Iranian traditional singers on the Dysphonia Severity Index (DSI) and the Singing Voice Handicap Index. The second objective was to examine the relationship between the DSI and Persian version of the Singing Voice Handicap Index (P-SVHI) scores in each group of trained and untrained Iranian traditional singers.

STUDY DESIGN

This study is a comparative cross-sectional study.

METHODS

This study included 17 trained male Iranian traditional singers who were compared with 17 untrained ones who were matched in terms of age. The P-SVHI was completed by trained and untrained Iranian traditional singers. Measures of jitter, lowest intensity, highest phonational frequency, and maximum phonation time (MPT) were obtained from each participant. The DSI scores were calculated using these values.

RESULTS

Trained male traditional singers had an average age of 33.76 ± 7.45 years, 3.24 ± 1.85 hours of daily practice, 5.24 ± 3.78 years of training, 3.06 ± 2.65 no. of professional performances, and untrained singers had an average age of 32.76 ± 12.92 years, 1.53 ± 1.17 hours of daily practice, and 0.88 ± 1.65 no. of professional performances. Trained singers had lower P-SVHI scores and sub-scores, longer MPT, higher F0 high, lower jitter, and lower I low, resulting in higher DSI values (P < 0.05). There was no significant correlation between P-SVHI scores and DSI values in each group of trained and untrained Iranian traditional singers (P > 0.05).

CONCLUSIONS

The results of this study show that the vocal abilities of professional vocalists are enhanced through voice training (higher DSI scores in trained singers vs untrained ones). Voice training can also help to lessen the perception of a handicap related to the singing voice. Hence, it may be necessary to consider alternative norms for the DSI and P-SVHI when administering them to patients who have undergone guided vocal training, such as voice/singing lessons. The current research indicates that the perception of singing voice handicap and DSI values are two distinct characteristics that do not have a significant correlation.

Looking for an Objective Parameter to Identify Early Vocal Dysfunctions in Healthy Perceived Singers

The finding of minimal laryngeal dysfunctions in professional voice users is essential to prevent the onset of organic vocal pathologies. The purpose of this study is to identify an objective parameter that supports the phoniatric evaluation in detecting minimal laryngeal dysfunctions in singers. 54 professional and non-professional singers have been evaluated with laryngostroboscopy, Multi-Dimensional Voice Program (MDVP), Dysphonia Severity Index (DSI), maximum phonation time (TMF), minimum intensity of sound emission (I-min), maximum frequency (F-max), voice handicap index (VHI), singing voice handicap index (SVHI), manual phonogram and audiometric examination. The SVHI of all the "healthy" singers was on average 23.7 ± 22.5, while that of the "dysfunctional" 20.9 ± 18. No statistically significant difference was found between the SVHI scores of the total of healthy singers compared to the scores of the dysfunctional ones on the VSL (p = 0.6). The between-group comparison of the means of individual parameter values of DSI, TMF, F-max, Jitter, Shimmer, NHR, and SPI was not statistically significant (respectively p = 0.315, 0.2, 0.18, 0.09, 0.2, 0.08, 0.3). The only parameter analyzed that was statistically significant was the I-min (p < 0.05). SVHI is a valid instrument for the evaluation after a therapy but in our experience, it is not useful in distinguishing healthy from dysfunctional patients. The minimum intensity of sound emission measured with the sound level meter (I-low2) resulted a reliable parameter to identify minimal laryngeal dysfunctions and a useful tool in supporting the phoniatric diagnostic-therapeutic process in singers.

Prospective Determination of Normative Value of the Singing Voice Handicap Index-10 (SVHI-10)

OBJECTIVES/HYPOTHESIS

To prospectively establish a normative value for the validated Singing Voice Handicap Index-10 (SVHI-10) patient reported outcome measure (PROM).

STUDY DESIGN

Prospective cross-sectional study.

METHODS

Adult singers without voice complaints were prospectively invited to complete a demographics questionnaire followed by the SVHI-10. Participants were excluded if they had sought medical care for voice changes within the last year or currently had throat problems. Statistical analysis was completed to establish a normative value and the distribution of demographics by singing experience, primary genre, and gender.

RESULTS

One hundred forty-nine healthy participants from diverse backgrounds (including singing, financial, educational, and geographic location) successfully completed the SVHI-10. The mean (SD) score of this cohort was 9.13 (5.15). We defined a normative value as two standard deviations above the mean: 19.43 There was no difference in SVHI-10 score in different age groups.

CONCLUSIONS

A normative value for the SVHI-10 questionnaire has been missing from the current literature and will be of great utility both in clinical practice and research. In previous research, singers have been shown to be more perceptive to quality change in their singing voices, which may be why the normative score is higher than one may expect. A SVHI-10 score ≥20 should be considered abnormal.

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.

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.

Are There Differences in Abdominal Muscle Function in Female Singers With and Without Voice Disorders? - An Observational Study

OBJECTIVES

The purpose of this study was to determine the motor function of the abdominal muscles in singers with and without functional voice disorders and to examine them for possible differences. Additionally, the breathing behaviour and posture control was investigated.

STUDY DESIGN

Observational study.

METHODS

Female subjects (n = 20) with differing levels of professional competence were used to provide the data for analysis. By using the Singing Voice Handicap Index (SVHI) the grade of dysphonia could be measured, and the subjects were organized in groups. The change of muscle thickness of the M. transversus abdominis (TVA) and the M. obliquus internus abdominis (OIA) during different singing tasks was measured by using ultrasound. The subjects were then asked to perform the Abdominal Hollowing Test (AHT) with the STABILIZER. Finally, the subjects were all filmed while singing. The videos recordings of the singing sessions were analysed by an independent clinical expert regarding breathing and secondary motor activities (SMA). For the statistical analysis, the Mann-Whitney-U Test and the Chi-Square-Test was mainly used.

RESULTS

The results showed a significantly thinner TVA in the group with dysphonia in comparison to the group without dysphonia. Ultrasound measurements showed significantly higher changes of muscle thickness of the TVA during singing tasks in the group with dysphonia. Regarding the AHT there was a significant difference between the two groups. The group with dysphonia was not able to increase the pressure by 15mmHg. Furthermore, the healthy subjects demonstrated abdominal breathing, while the group with dysphonia present with thoracic breathing. Additionally, it was noted that the subjects with dysphonia showed a higher level of associated movements especially at and/or on the lumbar spine, cervical spine and the left arm and shoulder.

CONCLUSION

Differences in TVA-recruitment, breathing behaviour and secondary motor activities while singing were found. This study sparks new ideas for neuromusculoskeletal assessments and therapy.

Reflux Symptom Index (RSI) and Singing Voice Handicap Index (SVHI) in Singing Students: A Pilot Study

OBJECTIVE

To correlate, RSI with SVHI, in a group of singing students, by means of a specific anamnestic questionnaire which analyzes the physical, social, emotional, and economic impacts of voice problems on their lives. This study is a cross-sectional single-center observational study.

METHODS

Forty-two modern singing students (26F/16M; average age: 24.9 ± 5.7; range: 16-46 years old) were recruited. A self-assessment of the singing-voice (SVHI) and of reflux symptom (RSI) was performed.

RESULTS

Using the validated RSI threshold, 31% of participants were classified as RSI greater than 13 as an indication of suspected LPR. Classifying the SVHI score as proposed in the recent literature (cutoff of 20.35) our sample was a voice disorders prevalence of 71.4%. There was no significant positive or negative relationship between RSI and SVHI total score (rho = 0.238, P = 0.13). Instead, by considering the relationship between the individual items of the two questionnaires, it is highlighted that the item 1 of SVHI was significantly correlated with most of the RSI items (P = 0.0001-0.006). In the same vein, the item 5 of SVHI was correlated to hoarseness and coughing (P = 0.005-0.006). The item 20 of SVHI was significantly correlated with hoarseness, excess mucus in the throat or postnasal drip and with the pharyngeal Globus sensation (P = 0.001-0.005). By aggregating the SVHI item response as a positive response (2-4) versus a negative response (0 or 1) between "RSI pathology classification," a significant association was observed for SVHI item 1 (P < 0.021), item 5 (P < 0.006), item 20 (P < 0.042), item 24 (P < 0.044) item 25 (P < 0.047). These associations were confirmed by univariate binary logistic. Multivariate binary logistic regression confirms that SVHI Item 1, Item 5 were more associated with RSI positive. Based on results, we propose a questionnaire that combines the most relevant SVHI items correlated to LPRD (SVHI-10-LPRD questionnaire). Cronbach's alpha coefficient for the 10 items selected was 0.87; item-total correlation coefficients for each item were in the range of 0.461 to 0.670.

CONCLUSIONS

This pilot study shows that, in case of significant RSI for LPR, it is possible to observe a significant association with some symptoms described in SVHI. These results underline that the association of the RSI and SVHI questionnaires administered to singers and singing students, can represent a simple screening to reveal possible alterations of the singing voice correlate to LPR. Moreover, we propose a Singing Voice Handicap Index correlated to LPR (SVHI-10-LPRD). It will be necessary to increase the sample of subjects in the study to confirm these preliminary data.