10.14639/0392-100X-N2311
Objective. The aim of this study was to adapt and validate the Italian version of the singing Voice Handicap Index-10 (SVHI-10-IT). Methods. 99 Italian singers were enrolled in the study. All subjects underwent videolaryngostroboscopic examination and were asked to fill out the self-reported 10-item SVHI- 10-IT. Laryngostroboscopic examination was pathological in 56 subjects (study group) (56.6%), while it was normal in the remaining 43 singers (control group) (43.4%). Dimensionality, test retest and internal validity for SVHI-10-IT were performed. Videolaryngostroboscopy was used as gold-standard for external validity. Results. The items of SVHI-10-IT were uni-dimensional and Cronbach’s α was 0.853 (95% CI = 0.805-0.892). High and comparable area under curve (AUC:0.93 95% CI = 0.88- 0.98) values indicate a good ability of the scale to distinguish between the study and control groups. Based on balanced sensitivity (Se = 83.9%) and specificity (Sp = 86.0%), the optimal cut-off score for a singer’s perceived voice handicap was 12. Conclusions. The SVHI-10-IT is a reliable and valid instrument to evaluate the self-reported singing voice handicap among singers. It can also be used as a quick screening tool since a score higher than 12 is indicative of a problematic voice as perceived by singers.
text/xml
1827-675X
2311
en
Luca Bastiani
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
dysphonia
Adaptation and validation of the Italian Singing Voice Handicap Index-10 (SVHI-10-IT)
Text.Serial.Journal
https://www.actaitalica.it/
43
Laryngology
2023-04-26
2022-09-23
2023-04-27
2023-04-27
114-122
1
Luca Bastiani
2023/04/26
10.14639/0392-100X-N2311
114
CNR Institute of Clinical Physiology, Pisa, Italy
1827-675X
dysphonia
en
122
Adaptation and validation of the Italian Singing Voice Handicap Index-10 (SVHI-10-IT)
https://www.actaitalica.it/article/download/2311/958
43
ACTA OTORHINOLARYNGOLOGICA ITALICA 2022;42:114-122; doi: 10.14639/0392-100X-N2311




Laryngology


Adaptation and validation of the
Italian Singing Voice Handicap Index-10 (SVHI-10-IT)
Adattamento e validazione in italiano del Singing Voice Handicap Index-10 (SVHI-10-IT)
Andrea Nacci1, Maria Rosaria Barillari2, Silvia Capobianco1, Bruno Fattori1, Stefano Berrettini1,
Alessandro Tonacci3, Fabrizio Minichilli3, Luca Bastiani3
1
 ENT Audiology Phoniatric Unit, University of Pisa, Pisa, Italy; 2 Department of Mental and Physical Health and Preventive Medicine,
“L. Vanvitelli” University, Naples, Naples, Italy; 3 CNR Institute of Clinical Physiology, Pisa, Italy


SUMMARY
Objective. The aim of this study was to adapt and validate the Italian version of the singing
Voice Handicap Index-10 (SVHI-10-IT).
Methods. 99 Italian singers were enrolled in the study. All subjects underwent videola-
ryngostroboscopic examination and were asked to fill out the self-reported 10-item SVHI-
10-IT. Laryngostroboscopic examination was pathological in 56 subjects (study group)
(56.6%), while it was normal in the remaining 43 singers (control group) (43.4%). Dimen-
sionality, test retest and internal validity for SVHI-10-IT were performed. Videolaryngos-
troboscopy was used as gold-standard for external validity.
Results. The items of SVHI-10-IT were uni-dimensional and Cronbach’s α was 0.853
(95% CI = 0.805-0.892). High and comparable area under curve (AUC:0.93 95% CI = 0.88-
0.98) values indicate a good ability of the scale to distinguish between the study and control
groups. Based on balanced sensitivity (Se = 83.9%) and specificity (Sp = 86.0%), the opti-
mal cut-off score for a singer’s perceived voice handicap was 12.
Conclusions. The SVHI-10-IT is a reliable and valid instrument to evaluate the self-report-
ed singing voice handicap among singers. It can also be used as a quick screening tool since
a score higher than 12 is indicative of a problematic voice as perceived by singers.
KEY WORDS: singing, Singing Voice Handicap Index, SVHI, SVHI-10, dysphonia                       Received: September 23, 2022
                                                                                                 Accepted: October 24, 2022

RIASSUNTO                                                                                        Correspondence
Obiettivo. Questo studio riporta il processo di validazione in lingua italiana del Singing       Andrea Nacci
Voice Handicap Index-10 (SVHI-10-IT).                                                            ENT, Audiology and Phoniatrics Unit, University
Metodi. 99 cantanti italiani hanno compilato il SVHI-10-IT dopo essere stati sottoposti a        of Pisa, Cisanello Hospital, via Paradisa, 2, 56124
laringostroboscopia, utilizzata come gold-standard di validità esterna. 56 soggetti presen-      Pisa, Italy
tavano lesioni patologiche (gruppo di studio) (56,6%), mentre i restanti 43 una morfologia       Tel. +39 050 997 518. Fax +39 050 997.501
                                                                                                 E-mail: a.nacci@med.unipi.it
nei limiti (gruppo di controllo) (43,4%). Sul questionario SVHI-10-IT sono state eseguite
prove di dimensionalità, test-retest e validità interna.
Risultati. Le variabili del SVHI-10-IT sono risultate uni-dimensionali e l’α di Cronbach           How to cite this article: Nacci A, Baril-
era 0.853 (CI 95% = 0,805-0,892). Valori alti e coerenti alla curva ROC (AUC = 0,93; CI            lari MR, Capobianco S, et al. Adaptation and
95% = 0,88-0,98) indicano l’abilità del questionario di distinguere tra soggetti patologici        validation of the Italian Singing Voice Handi-
e normali con un valore di cut-off di 12, calcolato basandosi su livelli equilibrati di sensi-     cap Index-10 (SVHI-10-IT). Acta Otorhi-
                                                                                                   nolaryngol Ital 2023;43:114-122. https://doi.
bilità (Se = 83,9%) e specificità (Sp = 86,0%).
                                                                                                   org/10.14639/0392-100X-N2311
Conclusioni. L’SVHI-10-IT è uno strumento valido e affidabile per valutare il livello di
handicap vocale auto-riferito in una popolazione di cantanti. Può essere applicato come
                                                                                                 © Società Italiana di Otorinolaringoiatria
strumento rapido di screening, utilizzando 12 come valore di cut-off indicativo di problema      e Chirurgia Cervico-Facciale
vocale.
PAROLE CHIAVE: canto, Singing Voice Handicap Index, SVHI, SVHI-10, disfonia                                     OPEN ACCESS

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                                                                                                 Commercial-NoDerivatives 4.0 International) license. The
                                                                                                 article can be used by giving appropriate credit and mentio-
Introduction                                                                                     ning the license, but only for non-commercial purposes and
                                                                                                 only in the original version. For further information: https://
The voice is the most extraordinary tool in the human relations. It expresses                    creativecommons.org/licenses/by-nc-nd/4.0/deed.en




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our state of being and is the elective way for communicating     languages of self-administered questionnaires is important
emotions. In addition, the voice is one of the main elements     not only to develop valid and reliable tools that can be used
of one’s identity, even sexual, and it becomes an instrument     in different countries, but also to confirm universally usable
of pleasure when listening or producing a sound. To deter-       reference values.
mine how a voice pathology can alter the quality of life, a      The Italian version of the SVHI-36 has proven its validity
multiparametric clinical evaluation of the voice is needed,      and reliability 9, but the SVHI-10 version has not yet been
which includes perceptual, self-evaluation and instrumental      validated in the Italian context. Therefore, the purposes of
analysis. There are several patient-reported outcome tools       this study were to adapt and validate the Italian version of
frequently used to determine the impact of voice impairment      the Singing Voice Handicap Index-10 (SVHI-10-IT) and to
and evaluate the results of possible treatment. These include:   determine the cut-off value using videolaryngostroboscopy
the Voice Quality of Life questionnaire 1, the Voice Symptom     diagnoses as external criteria.
Scale 2, the Voice Handicap Index (VHI) 3 and the VHI-10 4.
The VHI and the VHI-10 are the most commonly used ques-          Materials and methods
tionnaires for patient self-assessment. The VHI has been de-
veloped and translated into more than 20 languages to assess     Design and setting
the perceived voice handicap and at least nine translations of   This observational cross-sectional single-centre study was
the shorter version, the VHI-10, have also been published 5.     conducted in the ENT and Phoniatric private centre of Pisa,
Singers constitute a particular population that pays close       Italy. Singers included in the study performed different mu-
attention to the disturbances of singing voice 6. For pro-       sic genres (contemporary commercial music and classic)
fessional or non-professional singers, any small deviation       and came from a range of experience levels (singing stu-
in voice quality can have consequences on their quality          dent, amateur or professional).
of life, causing problems in the emotional sphere. There-        A total of 99 Italian singers (known patients or new afferent
fore, singers have particular demands from their voice. A        ones) who were evaluated consecutively in the private ENT
specific questionnaire, the Singer Voice Handicap Index          and Phoniatric centre were enrolled in the study. Overall,
(SVHI), has been created with the aim of measuring the           participants had a mean age of 29.8 years (sd 9.7; range
physical, social, emotional and economic impact of voice         18-54 years), with demographic characteristics shown in
problems on singers’ lives 7. The SVHI is a specific tool        Table I. All subjects underwent videolaryngostroboscopic
to assess self-perceived handicap associated with singing        examination and were asked to fill out the self-reported
problems and is more reliable and valid than the VHI to as-      10-item SVHI-10-IT. To ascertain the inter-rater reliability
sess the singer’s voice problems 8. It consists of 36 items to   of videolaryngostroboscopic examination, Cohen’s kappa
which subjects must answer with a score between 0 and 4,         coefficient was calculated between two observers. Laryn-
with zero equal to “never” and 4 equal to “always”. State-       gostroboscopic examination was pathological in 56 sub-
ments are related to the physical, emotional and social as-      jects (study group) (56/99; 56.6%), while it was normal in
pects arising from a disturbed singing voice. This reliable      the remaining 43 singers (control group) (43/99; 43.4%)
tool has been adapted and validated for many languages,          (Cohen’s kappa 0.938; p-value = 0.001).
including Italian 9. According to Cohen et al. 10, the SVHI      To confirm test-retest reliability of the SVHI-10-IT, pa-
with 36 statements 7 can be difficult to apply in all singers,   tients were invited to complete the questionnaire for a sec-
especially when used for repeated measurements. For this         ond time, approximately 2 weeks after the first administra-
reason, the same authors have developed and validated a          tion. Medical data were collected by review of medical care
shorter version of the SVHI, the Singing Voice Handicap          records. Absent responses were checked by the authors af-
Index-10 (SVHI-10) 10, for which other validations have          ter receiving the questionnaire and patients were eventually
been carried out 11-13. Although the SVHI-10 subscales are       asked to answer to the missing items.
described 11, in the literature there are no studies analys-
ing in detail the factorial structure of the questionnaire to    SVHI-10 questionnaire
evaluate the presence or absence of subscales (Functional,       The SVHI-10 was developed and validated at the Duke Uni-
Physical and Emotional). The SVHI-10 has a five-point            versity Medical Center of Carolina 10. It provides a measure
rating scale, with zero equal to “never”, 1 equal to “al-        of the severity of voice handicap associated with singing
most never”, 2 equal to “sometimes”, 3 equal to “almost          voice problems. It consists of 10 items, six of which under
always”, and 4 equal to “always”. The higher the score, the      the physical subscale, and the remaining 4 belonging to the
greater the self-perception of disability regarding a sing-      functional (2) and emotional (2) domains, respectively. As
ing voice problem. The adaptation and validation in other        the SVHI-10 is a self-administered tool, subjects are asked



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Table I. Demographic characteristics of the study and control groups.
 Parameter                                                            Study group (n. 56)     Control group (n. 43)         P-value
Age (years)
  Mean ± SD                                                              29.3 ± 9.4               30.4 ± 10.2                0.592*
Gender n (%)
  Female                                                                 30 (53.6%)                24 (55.8%)               0.824**
  Male                                                                   26 (46.4%)                19 (44.2%)
Singing status n (%)
  Amateur                                                                16 (28.6%)                12 (27.9%)               0.992**
  Student                                                                25 (44.6%)                19 (44.2%)
  Professional                                                           15 (26.8%)                12 (27.9%)
Singing style n (%)
  Contemporary commercial music                                          39 (69.6%)                31 (72.1%)               0.791**
  Classic music                                                          17 (30.4%)                12 (27.9%)
*
    Independent t-test; ** Chi-square.



to rate each statement on a 5-point ordinal Likert scale from                  Categorical variables were expressed as percentages, and con-
“0” to “4”, with higher scores indicating a more severe voice                  tinuous variables were expressed according to their mean and
problem-related disability. The sum of individual scores pro-                  standard deviation (SD).
duces the overall score, ranging from 0 to 40, with higher
scores representing greater levels of voice problems.                          Translation procedure of the SVHI-10-IT
                                                                               The 10 items of the SVHI-10 were translated according to
Videolaryngostroboscopic examination                                           international guidelines 15 as follows: (1) two independent
Videolaryngostroboscopic examinations were performed                           Italian translations were obtained from two independent
via a rigid endoscope using the Ecleris digital stroboscope                    translators who were native Italian speakers with profi-
led, stroboled model (Ecleris USA, Medley, FL, USA).                           ciency in English. Cross-cultural adaptation was achieved
The examination was based on visualisation of subjects at                      during a consensus meeting. (2) The back-translation from
comfortable loudness and modal phonation of the /e/ vowel                      Italian to English was carried out by a native English speak-
sound in agreement with the criteria listed by Hirano’s book                   er who was not involved in developing the initial version.
on videostroboscopy 14. Glottal closure configuration, vocal                   (3) The original and the back-translated English versions
fold edge, vocal fold vibratory characteristics, and mucosal                   were compared to ensure that there were no differences in
wave represented the main parameters evaluated. Laryngeal                      the meaning of the statements in the questionnaire; incon-
pathology and functional dysfunction (supraglottic hyper-                      sistencies were discussed and resolved among the trans-
function) were assessed. All stroboscopic examinations were                    lators until a final version was obtained. A pilot test was
stored on a hard disk for re-evaluation at a later stage.                      performed in a small sample (n = 10) aimed at clarifying
                                                                               the exact wording for each item. Since the questions were
Statistical analysis                                                           correctly interpreted by all subjects, no item was modified.
We analysed the Singing Voice Handicap Index-10 (SVHI-                         The average time necessary to complete the SVHI-10-IT
10-IT) statements collected in our study to adapt and validate                 was less than 4 minutes, and the questionnaire was well
the Italian version using four standard questionnaire validation               understandable and acceptable in most subjects.
steps: 1) Translation procedure of the SVHI-10-IT; 2) Test-
Retest Reliability; 3) Internal validity; 4) External validity.                Test-retest reliability
Subsequently; 5) Principal Component Analysis (PCA) was                        Reproducibility of the scale was estimated through a test-
used to explore the SVHI-10-IT factorial structure and iden-                   retest reliability in a 2-week window. The agreement be-
tify the latent variables indicated by our observed variables.                 tween the repeated measures was examined using the in-
Finally, we performed a confirmatory factor analysis (CFA)                     traclass correlation coefficient (ICC). An ICC < 0.40 was
via 6) Structural Equation Modelling (SEM) to confirm the                      rated as poor agreement, values between 0.40 and 0.75
presence of one or more latent variables. All statistical analy-               as fair to good agreement and values > 0.75 as excellent
ses were completed using Stata/SE 13.1 and SPSS Version 24.                    agreement 16.



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Internal validity                                                  eling (SEM), was used to test an overall measurement model
Cronbach’s alpha was used to assess internal consisten-            that included correlated latent variables 18. SEM typically re-
cy with values above 0.7 indicating desirable levels. The          fers to models where causal relationships are investigated be-
Cronbach’s alpha cut-off were: 0.7 ≤ α < 0.8, Acceptable;          tween latent variables. The CFA process determines whether
0.8 ≤ α < 0.9, Good; 0.9 ≤ α, Excellent 23. Additionally, to       the hypothesised structure provides a good fit to the data, or
investigate the psychometric properties of the items, inter-       whether a relationship exists between the observed variables
item association and Cronbach’s alpha with deleted items           and their underlying latent, or unobserved, constructs 19. The
were also computed.                                                overall model fit was assessed using different statistics. First,
                                                                   chi-square analysis was used. The other indices included the
External validity                                                  Root Mean Square Error of Approximation (RMSEA) (val-
An independent sample t-test was used to assess differ-            ues between 0.05 and 0.08 indicate acceptable fit, and values
ences in SVHI-10-IT mean scores between control and                < 0.05 good fit), Comparative Fit Index (CFI) (values > 0.90
study groups. In order to determine optimal thresholds for         indicate reasonable fit, > 0.95 good fit), and Standardised
SVHI-10 Italian version when compared to videolaryngo-             Root Mean Square Residual (SRMR) (values < 0.10 indicate
stroboscopic diagnoses, Receiver Operator Characteristic           good fit). The measurement model was first tested to ensure
(ROC) curve analysis was performed. To determine the               that each of the observed variables was a sufficient indicator
best balance between sensitivity and specificity, the Youden       of the hypothesised latent variables. Next, the model includ-
index (Y = sensitivity+specificity-1) was chosen as the cri-       ing the hypothesised pathways was evaluated.
terion for selecting cut-off values. Statistical analysis was
performed using SPSS, v.24.0 (IBM Corporation, Natick,             Sample size calculation
MA, USA and statistical significance was set at p ≤ 0.05           To determine optimal sample-size of this study, we refer
(two-sided).                                                       to the frequently promoted N:t rule of thumb concerns the
                                                                   minimum recommended ratio of sample size (N) to number
SHI-10-IT factorial structure and structural equations             of items (t) of the questionnaire. Various N:t ratios were
model analysis (SEM)                                               proposed in literature, the typical 10:1 ratio; 7:1 ratio; 5:1
Principal Component Analysis (PCA) was performed to ex-            ratio, but also the 3:1 and 2:1, was suggested 20. In particu-
plore the SVHI-10-IT factorial structure and to identify the       lar, SVHI has 10 items. Thus, with t = 10, we estimated a
latent variables indicated by our observed variables 8,11. To      minimal sample size of 20 = 10 x 2, or N = 30 for a 3:1
explore the SVHI-10-IT construct validity as proposed in           ratio, or N = 50 for a 5:1 ratio, or N = 70 for a 7:1 ratio, or
other works, the PCA was performed to evaluate the dimen-          N = 100 for 10:1 ratio.
sionality of 10 items into the domains of physical, function-
al, and emotional categories. The number of dimensions and
                                                                   Results
the item loading structure of PCA with orthogonal rotation
(varimax method) was conducted on the correlation matrix           Patients
of the SVHI-10-IT items. Three classical criteria from PCA         No significant differences in age (p = 0.592) or gender
were used: 1) eigenvalue rule (number of factors with eigen-       (p = 0.824) were observed between the study group and
values > 1); 2) Scree plot (number of factors before the break     controls. Singing status distribution was the same in both
in the Scree plot); 3) factor loading rule (item–factor correla-   groups. Singing students were the majority, being 44.6% in
tions > 0.32, suggested for behavioral phenotypes interpreta-      the study group and 44.2% in the control group. Professional
tion). To facilitate interpretation, the authors usually employ    singers were 26.8% of participants in the study group and
cut-off points in rotated factor loadings to find factor names.    27.9% in the control group. Amateur singers made up 28.6%
For instance, in epidemiology it is frequent to use a cut-off of   of the study group and 27.9% of the control group. The sing-
0.30, i.e., variables with loadings lower than this cut-off are    ing style also did not differ between the two groups; most
not considered when creating the name of the factor. In this       singers were under the category “contemporary commer-
application, we used a cut-off of 0.50.                            cial music” (Study group: 69.6% vs Control group: 72.1%;
                                                                   p = 0.791), while the others were classic music singers. Ta-
Confirmatory factor analysis (CFA) via Structural                  ble II shows the distribution of the study group diagnoses,
Equation Modelling (SEM)                                           which included laryngopharyngeal reflux (LPR) (26.8%),
Finally, CFA via SEM was performed to test the SVHI-10-IT          vocal nodules (21.5%), submucosal oedema (19.6%), polyps
factorial structure highlighted by the PCA. The CFA, which         (10.7%), functional dysphonia (8.9%), cysts (7.1%), corditis
is a special case of what is known as structural equation mod-     (3.6%) and vascular lesions (ectasia) (1.8%).



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Table II. Primary diagnosis in the study group.                                       do what I want it to”. The item with the lowest value of total
 Primary diagnosis                                                   %                correlations was “It takes a lot of effort to sing”, leading the
 Laryngopharyngeal reflux (LPR)                                    26.8               Cronbach’s alpha to increase to 0.849 with its elimination.
 Vocal nodules                                                     21.5
 Submucosal oedema                                                 19.6               External validity
 Polyps                                                            10.7               Independent t-test and ROC curve analysis
 Functional dysphonia                                              8.9                SVHI-10-IT mean score was 6.0 ± 4.0 among the control
 Cysts                                                             7.1                group and 17.0 ± 5.9 in the study group (p = 0.0001). The
 Corditis                                                          3.6                mean scores were not significantly different between sing-
 Vascular lesion (ectasia)                                         1.8                ing style: 12.5 ± 7.9 for modern and 11.6 ± 6.6 for classic
                                                                                      singers (p = 0.570). Different averages in the SVHI-10-IT
                                                                                      were not observed among students (10.9 ± 6.5), amateurs
Test-retest reliability and psychometric properties                                   (14.5 ± 6.9) and professionals (12.2 ± 9.3) (Anova p-val-
Eighty-five per cent of the overall sample (study group:                              ue = 0.142). The ROC curve analysis was performed to
45/56; control group: 39/43) completed the SVHI-10-IT at                              define the cut-off point, specificity and sensitivity. The ob-
two time points. SVHI-10-IT total scores between first and                            served Youden Index (YI) for the SVHI-10-IT was equal to
second visits were used to assess the test-retest reliability,                        0.700 and the optimal cut-off point determined was 12. The
which was good with an ICC value of 0.79 (95% confi-                                  Area Under the ROC curve was 0.93.0 (95% CI = 0.88-
dence interval (CI) = 0.67-0.87). Among the SVHI-10-IT                                0.98) and high sensitivity and specificity were observed
items, the ICC varied between 0.72 and 0.87.                                          (Se = 83.9%; Sp = 86.0%).
SVHI-10-IT Cronbach’s alpha was 0.853 (95% CI = 0.805-
0.892), showing good internal consistency of the question-                            Construct validity
naire. The psychometric properties examined showed a good                             All the coefficients of the correlation matrix among SVHI-
level for all items, as displayed in Table III. The items present-                    10-IT items were greater than 0.3, suggesting that all 10 items
ing the highest values were “I feel something is missing in my                        could be significantly taken into account. For SVHI-10-IT
life because of my inability to sing”, “I have no confidence                          items, the PCA identified two Principal Components (PC)
in my singing voice” and “I have trouble making my voice                              with eigenvalues > 1. The first eigenvalue was equal to 4.335


Table III. Psychometric properties: item-total correlation and Cronbach’s alpha if item 1 was deleted.
                                                                                                         Corrected item-total   Cronbach’s Alpha if item 1
                                                                                                             correlation              was deleted
 Item 1. (P) It takes a lot of effort to sing                                                                   0.457                     0.849
 Mi occorre un notevole sforzo per cantare
 Item 2. (F) I am unsure of what will come out when I sing                                                      0.508                     0.843
 Non sono sicuro/a di cosa verrà fuori quando canto
 Item 3. (P) My voice ‘‘gives out’’ on me while I am singing                                                    0.518                     0.843
 La mia voce viene meno mentre canto
 Item 4. (E) My singing voice upsets me                                                                         0.541                     0.841
 La mia voce cantata mi irrita, mi agita
 Item 5. (F) I have no confidence in my singing voice                                                           0.651                     0.830
 Non mi fido della mia voce cantata
 Item 6. (P) I have trouble making my voice do what I want it to                                                0.644                     0.831
 Ho problemi nel far fare alla mia voce ciò che voglio
 Item 7. (P) I have to ‘‘push it’’ to produce my voice when singing                                             0.490                     0.844
 Devo “spingere” per produrre la mia voce quando canto
 Item 8. (P) My singing voice tires easily                                                                      0.602                     0.835
 La mia voce cantata si stanca facilmente
 Item 9. (E) I feel something is missing in my life because of my inability to sing                             0.654                     0.829
 Sento che manca qualcosa alla mia vita a causa dei miei problemi nel canto
 Item 10. (P) I am unable to use my ‘‘high voice’’                                                              0.521                     0.842
 Sono incapace di utilizzare i toni acuti




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Table IV. Factor loadings coefficients: the contribution of each observed variables considered as predictor, to define the components.
                                  Rotated component matrix                                                                  Component
                                                                                                           Physical                 Emotional-functional
 Item 1. (P) It takes a lot of effort to sing                                                                0.670                         0.070
 Item 2. (F) I am unsure of what will come out when I sing                                                   0.110                         0.758
 Item 3. (P) My voice ‘‘gives out’’ on me while I am singing                                                 0.691                         0.175
 Item 4. (E) My singing voice upsets me                                                                      0.096                         0.821
 Item 5. (F) I have no confidence in my singing voice                                                        0.184                         0.871
 Item 6. (P) I have trouble making my voice do what I want it to                                             0.568                         0.477
 Item 7. (P) I have to ‘‘push it’’ to produce my voice when singing                                          0.701                         0.140
 Item 8. (P) My singing voice tires easily                                                                   0.846                         0.138
 Item 9. (E) I feel something is missing in my life because of my inability to sing                          0.364                         0.696
 Item 10. (P) I am unable to use my ‘‘high voice’’                                                           0.646                         0.230



and the second equal to 1.573, which explained for 59.10%                             important predictors were SVHI-10-IT Item 6 (“I have
(first eigenvalue 43.34% + second eigenvalue 15.73%) of the                           trouble making my voice do what I want it to”) (β = 0.805,
observed total variance; the Scree plot pointed out two PCs.                          SE = 0.057, p < 0.0001), and SVHI-10-IT Item 8 (“My sing-
Thus, rotation was performed, and dimensionality of the                               ing voice tires easily”) (β = 0.728, SE = 0.061, p < 0.0001).
SVHI-10-IT was explored. Applying a factor loading cut-off                            The annoyance the singer feels when he/she hears his/her
of |0.50| to simplify the interpretation of the factor structure,                     own voice (SVHI-10-IT Item 4: β = 0.734, SE = 0.055,
we observed two factors (Tab. IV). The first factor, labeled                          p < 0.0001) and the insecurity of what will come out when
the “Physical Component”, was strongly influenced by the                              he/she sings (SVHI-10-IT Item 2: β = 0.863, SE = 0.043,
following statements: item 1: (P) It takes a lot of effort to                         p < 0.0001) were the most important predictors in the Emo-
sing; item 3:(P) My voice ‘‘gives out’’ on me while I am                              tional-Functional component.
singing; item 10: (P) I am unable to use my ‘‘high voice’’;                           The standardised paths of SVHI-10-IT factorial structure
item 6: (P) I have trouble making my voice do what I want it                          highlighted via Structural Equation Modelling (SEM)
to; item 7: (P) I have to ‘‘push it’’ to produce my voice when                        from the two components to their respective variables were
singing; item 8: (P) My singing voice tires easily. Cron-                             specified in Figure 1. The Structural Model Fit indices sug-
bach’s alpha for the “Physical Component” was 0.812 (CI                               gested that the proposed model fits the data (χ2 = 34.78
95% = 0.748-0.864). The second factor, labeled the “Emo-                              [df = 28, p = 0.176], RMSEA = 0.049, SRMR was 0.050
tional-Functional Component”, was strongly influenced by                              and CFI = 0.982). The indices for the proposed model
the statements: item 4: (E) My singing voice upsets me; item                          showed that the measurement model fits adequately 21 and
5: (F) I have no confidence in my singing voice; item 2: (F)                          all standardised paths were significant (Fig. 1). Finally, the
I am unsure of what will come out when I sing; item 9: (E) I                          “Physical” and “Emotional-Functional” components were
feel something is missing in my life because of my inability                          positively associated (β = 0.656, SE = 0.078, p < 0.0001).
to sing. The Cronbach’s alpha for the “Emotional-Functional
Component” was 0.832 (CI 95% = 0.770-0.880).
                                                                                      Discussion
Confirmatory factor analysis via structural equation                                  Singers represent a special population with high risk for
modelling                                                                             developing and perceiving alterations of voice compared
SEM was performed to confirm the latent variable high-                                to non-singing subjects 6. Within this framework, to better
lighted in the PCA and, as described in Table V, the two                              understand the manifold problems of the singing voice, a
SVHI-10-IT components (Physical and Emotional-Func-                                   specific questionnaire, the SVHI, was created with the aim
tional) provided an acceptable explanation for their cor-                             of measuring the physical, social, emotional and economic
responding observed variables, since all the coefficients                             impact of voice problems on singers’ lives 7. This reliable
were above 0.400 21. Standardised regression coefficients,                            tool has been adapted and validated for many languages,
reported in Table V, explain the contribution of each of the                          including Italian 9. Due to the fact that the SVHI can be
observed variables considered as predictor, to define the                             difficult to apply to all singers, Cohen et al. developed and
components. Thus, for the Physical component, the most                                validated a shorter version of the SVHI, the SVHI-10 10



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Table V. Standardised regression coefficient for the Structural Model.
 SVHI-10 component                SVHI-10, observed variables                  Standardised         Standard          P>z            Standardised
                                                                                regression            error                           regression
                                                                                coefficient                                         coefficient (95%
                                                                                                                                           CI)
Physical             Item 1. (P) It takes a lot of effort to sing                  0.439             0.094            0.0001          0.253-0.625
                     Item 3. (P) My voice ‘‘gives out’’ on me while I am           0.652             0.088            0.0001          0.479-0.825
                     singing
                     Item 6. (P) I have trouble making my voice do what I          0.805             0.057            0.0001          0.691-0.919
                     want it to
                     Item 7. (P) I have to ‘‘push it’’ to produce my voice         0.554             0.078            0.0001          0.400-0.707
                     when singing
                     Item 8. (P) My singing voice tires easily                     0.728             0.061            0.0001          0.608-0.849
                     Item 10. (P) I am unable to use my ‘‘high voice’’             0.644             0.072            0.0001          0.502-0.786
Emotional-functional Item 2. (F) I am unsure of what will come out when I          0.863             0.043            0.0001          0.777-0.950
                     sing
                     Item 4. (E) My singing voice upsets me                        0.734             0.055            0.0001          0.625-0.842
                     Item 5. (F) I have no confidence in my singing voice          0.715             0.058            0.0001          0.560-0.830
                     Item 9. (E) I feel something is missing in my life            0.643             0.068            0.0001          0.509-0.777
                     because of my inability to sing




Figure 1. The Structural Model; χ2: Chi-square; RMSEA: Root Mean Square Error of Approximation; SRMR: Standardised Root Mean Square Residual; CFI: Com-
parative Fit Index.



120
                                                                                                               Validation of SVHI-10-IT




which, however, has not been validated in the Italian con-          that explores, through Principal Component Analysis (PCA)
text. Therefore, the aims of this study were to adapt and           and Structural Equation Model (SEM), the best indicators for
validate the Italian version of SVHI-10 (SVHI-10-IT) and            voice handicap in singers, considering both the involvement
to determine its psychometric properties when translated.           of each VHI-10 variable of the different components affecting
In fact, in singers, whether students, professionals, or ama-       singers’ voices (Physical, Emotional and Functional) and the
teurs, each small variation in singing voice can determine          relationship between the two components. Our study showed
a deviation in their quality of life, with important conse-         that the SVHI-10-IT lists six statements related to voice physi-
quences from emotional and functional points of view. In            cal aspects, with the remaining four being related to emotional
case of a voice alteration as a consequence of both organic         and functional needs. In research conducted in the USA, aim-
and functional disturbances, there might be alterations in          ing to compare the differences in the scores between VHI-10
the emotional and functional sphere that can further wors-          and SVHI-10 in professional singers and students, Renk and
en both the quality of life and self-perception of the prob-        colleagues categorised the SVHI-10 items into the broad cat-
lem. Thus, a vicious circle between physical, functional            egories of Physical (P: items 1, 3, 6, 7, 8, 10), Functional (F:
and emotional spheres may have detrimental effects on a             items 2, 5), and Emotional (E: 4, 9) 8. Nevertheless, in the same
singer’s ability to withstand the problem, which can hardly         study, after comparing the items means, it was reported that
be solved if not correctly diagnosed in the various com-            SVHI-10 seems to have only two statements related to func-
ponents. Therefore, as singers have specific needs from
                                                                    tion with the remaining eight being related to emotional and
their voice, their evaluation concerning voice complaints
                                                                    physical needs. However, to confirm the results of our study
requires a multiparametric approach. This approach should
                                                                    also from a clinical point of view, the items that investigate the
include patient-reported outcomes, along with clinician-
                                                                    functional component (Items 5 and 2: “I have no confidence
based perceptual evaluations and instrumental analyses 22.
                                                                    in my singing voice” and “I am unsure of what will come out
According to our results, construct validity was tested using
                                                                    when I sing”) appear closely related to those investigating the
reliability analysis and was confirmed by good Cronbach’s
alpha index (0.853), test-retest coefficient and significant as-    emotional component (Items 4 and 9: “My singing voice up-
sociation between total score (ICC: 0.79) and for each item         sets me” and “I feel something is missing in my life because of
(ranged from 0.72 to 0.87). This finding is comparable with         my inability to sing”). On the contrary, the items investigating
the original version of SVHI-10 10 and with other SVHI-10           the physical component (Items 1, 3, 6, 7, 8,10) seem to mainly
validation studies 11,13,23. Cohen and Rangarajan reported an       investigate the problem of the voice resulting from a disor-
excellent Cronbach’s alpha above 0.930 and in the Kannada           der of the phono-articulatory system. In the final analysis, as
and Turkish validation the reliability index was equal to 0.91.     shown by our results, the physical component also correlated
All the item-total correlation coefficients were found to be        with the emotional/functional one (Fig. 1).
higher than 0.45 and Cronbach’s alpha coefficients obtained         Our study has some limitations, the sample size in this re-
when any item was deleted demonstrated that all the items are       search being not extremely large and the results referring
consistent with the questionnaire. A ROC curve analysis was         to subjects enrolled in a single centre. A multicentre inves-
performed to determine the sensitivity and specificity of the       tigation would improve future studies by providing larger
index. The AUC, which was equal to 0.93, demonstrated the           samples with more generalisable findings.
high accuracy for the system 24. In our results, high sensitivity
and specificity values (Se = 0.839; Sp = 0.860) indicated that      Conclusions
the SVHI-10-IT owns a good capability of reflecting the sing-
ers’ self-perceived handicaps. With respect to videolaryngo-        Our results suggest that the SVHI-10-IT is a reliable and
stroboscopic diagnoses, our cut-off point was 12, which was         valid tool for evaluating the self-reported singing voice
equal to the Turkish validation, but higher than that obtained      handicap among singers. A SVHI-10-IT score of 12 can be
in the Kannada validity study 12,13 and compared to the results     used as the indicative cut-off point of a perceived problem-
of a recent Systematic Review and Meta-Analysis 25. As such,        atic voice in singers. Furthermore, the SVHI-10-IT factorial
PCA was conducted to determine construct validity and to            structure was explored and the two dimensions describing
answer the question: is SVHI-10-IT one-dimensional or does          Physical and Emotional/Functional aspects were described.
it have different underlying dimensions? Construct validity         Future studies are needed to confirm the factorial structure
analysis performed by PCA showed that SVHI-10-IT items              and validate the subscales of the SVHI-10.
were two-component: the first dimension refers to Physical
aspects, while the second includes Emotional and Functional         Conflict of interest statement
aspects. To the best of our knowledge, this is the first study      The authors declare no conflict of interest.



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A. Nacci et al.




Funding                                                                     6
                                                                                 Nacci A, Baracca G, Romeo SO, et al. Endoscopic and phoniatric
                                                                                 evaluation in singing Students. J Voice 2019;33:135-142. https://doi.
This research did not receive any specific grant from fund-
                                                                                 org/10.1016/j.jvoice.2017.10.006
ing agencies in the public, commercial, or not-for-profit                   7
                                                                                 Cohen SM, Jacobson BH, Garrett CG, et al. Creation and validation
sectors.                                                                         of the Singing Voice Handicap Index. Ann Otol Rhinol Laryngol
                                                                                 2007;116:402-406. https://doi.org/10.1177/000348940711600602
Author contributions                                                        8
                                                                                 Renk E, Sulica L, Grossman C, et al. VHI-10 and SVHI-10 differ-
AN, LB, MRB, SB: designed the study, interpreted the                             ences in singers’ self-perception of dysphonia severity. J Voice
                                                                                 2017;31:383E1-383.E4. https://doi.org/10.1016/j.jvoice.2016.08.017
study results, and wrote the article; AN: directed study im-                9
                                                                                 Baracca G, Cantarella G, Forti S, et al. Validation of the Italian ver-
plementation including quality assurance and control; AN,                        sion of the singing voice handicap index. Eur Arch Otorhinolaryngol
MRB, BF, SC, LB: interpreted the study results and wrote                         2014;271:817-823. https://doi.org/10.1007/s00405-013-2658-y
the article; AT: prepared data for statistical analysis; LB:                10
                                                                                 Cohen SM, Statham M, Rosen CA, et al. Development and validation
performed statistical analysis; AN: supervised field activi-                     of the Singing Voice Handicap-10. Laryngoscope 2009;119:1864-
                                                                                 1869. https://doi.org/10.1002/lary.20580
ties. All authors critically reviewed the article for important             11
                                                                                 Rangarajan A, Santhanam DP, Selvaraj JL. Translation and valida-
intellectual content and approved the final manuscript.                          tion of Thamil version of singing voice Handicap Index-10. J Voice
                                                                                 2020;34:158-165. https://doi.org/10.1016/j.jvoice.2018.08.003
Ethical consideration                                                       12
                                                                                 Esen Aydinli F, Akbulut S, Özcebe E, et al. Validity and reliability of
The study is observational cross-sectional single-center                         the Turkish singing voice handicap index-10. J Voice 2018;34:304-
                                                                                 329. https://doi.org/10.1016/j.jvoice.2018.11.011
study and conducted in a private center. We enrolled both
                                                                            13
                                                                                 Gunjawate DR, Aithal UV, Bellur R. Adaptation and validation of the
known patients and new afferent patients to the ENT and                          Kannada Singing Voice Handicap Index-10. J Voice 2018;4;582.E1-
Phoniatric private Center of Pisa. According to General                          582.E4. https://doi.org/10.1016/j.jvoice.2018.02.005
Data Protection Regulation (GDPR) the written statement                     14
                                                                                 Hirano M, Bless DM. Videostroboscopic examination of the larynx.
were signed by each subject. All subjects read the pur-                          San Diego, Calif: Singular Pub. Group, ©1993.
pose of the study and agreed to answer the ten questions                    15
                                                                                 Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation
                                                                                 of health-related quality of life measures: literature review and pro-
of the proposed questionnaire (Singing Voice Handicap In-
                                                                                 posed guidelines. J Clin Epidemiol 1993;46:1417-1432. https://doi.
dex-10). Although this study is registered as European Un-                       org/10.1016/0895-4356(93)90142-n
ion electronic Register of Post-Authorisation Studies (EU                   16
                                                                                 Nunnely JC, Bernstein IH. Psychometric theory, third edition.
PAS) 41469, we do not have documentation submitted to                            New York, NY: McGraw-Hill; 1994. pp. 303-305. https://doi.
the ethics committee. As a private center, each patient has                      org/10.1177/014662169501900308
viewed and signed the document concerning Information
                                                                            17
                                                                                 Cronbach LJ. Coefficient alpha and the internal structure of tests. Psy-
                                                                                 chometrika 1951;16:297-334. https://doi.org/10.1007/BF02310555
about the processing of personal data of patients (Direc-                   18
                                                                                 Henriquez P, Matuszewski BJ, Andreu-Cabedo Y, et al. Mirror on
tive 95/46/EC - GDPR), which also includes the use of data                       the wall. An unobtrusive intelligent multisensory Mirror for well-be-
for scientific research purposes. Ethical approval was not                       ing status self-assessment and visualization. IEEE Transactions
required for this study in accordance with local guidelines.                     on Multimedia. 2017;19:1467-1481. https://dx.doi.org/10.1109/
                                                                                 TMM.2017.2666545
                                                                            19
                                                                                 Child D. The essentials of factor analysis, second edition. London,
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