Meta-Analysis on the Validity of the Acoustic Voice Quality Index

Impact of Cultural-Linguistic Differences on Vocal Fatigue Perception: A Systematic Review and Meta-Analysis

PURPOSE

The perception of a clinical condition or disorder can vary across patients from different cultural-linguistic backgrounds. There is insufficient evidence to inspect this potential impact on the perception of vocal fatigue (VF) as a common condition perceived by patients with voice disorders. In order to more comprehensively explore this phenomenon, a systematic review was carried out to investigate the differences in perceived VF in a variety of cultural-linguistic contexts, based on a standard self-assessment instrument-the Vocal Fatigue Index (VFI), as translated in different languages.

METHOD

A thorough search was done in MEDLINE, CENTRAL, Web of Science, and Google Scholar by March 2024. Cross-sectional studies investigating the accuracy of the VFI to detect perceived VF in all available languages were considered. The VFI has three distinct parts or factors assessing: (a) tiredness of voice, (b) physical discomfort associated with voicing, and (c) improvement of symptoms with rest. The cutoff points and sensitivity and specificity of each factor were submitted to meta-analysis, and the summary receiver operating characteristic curves were used to determine pooled sensitivity and specificity of each factor of the VFI.

RESULTS

Eight papers that examined the diagnostic accuracy of the VFI in English, Malayalam, Turkish, German, Mandarin Chinese, Polish, Cantonese, and Finnish languages were identified as being eligible for this meta-analysis. The pooled sensitivity and specificity along with their confidence intervals (CIs) were as follows: 0.91 CI [0.80, 0.96] and 0.88 CI [0.78, 0.94] for Factor 1, 0.83 CI [0.69, 0.91] and 0.84 CI [0.76, 0.89] for Factor 2, and 0.75 CI [0.67, 0.82] and 0.77 CI [0.59, 0.89] for Factor 3.

CONCLUSIONS

The present research demonstrates medium to high but heterogeneous accuracy of the VFI for detecting perceived VF across cultural-linguistic contexts. Given the promising results, future studies should focus on (a) further investigating the underlying factors for the observed heterogeneity in diagnostic accuracy and (b) adapting and validating the VFI in more languages toward establishing its validity as a cross-linguistic diagnostic tool for the perception of VF.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.26397106.

A Retrospective Study of Acoustic Measures of Glottal Stop Production to Assess Vocal Function in Unilateral Vocal Fold Paresis/Paralysis Patients

PURPOSE

The aim of this study was to determine (a) diagnostic accuracy of acoustic measures of glottal stop production (GSP; intensity differences, slopes, complete voicing cessation) to distinguish between unilateral vocal fold paresis/paralysis (UVFP) patients and controls; (b) if acoustic measures of GSP significantly correlated with an acoustic measure of voice disorder severity, acoustic voice quality index (AVQI); and (c) if acoustic measures from another type of voicing cessation, voiceless consonant production, also significantly differed between groups.

METHOD

Ninety-seven patients with unilateral paresis/paralysis and 35 controls with normal laryngostroboscopic signs produced two sets of five repeated [i] and four repeated [isi]. Tokens were randomized by type between groups and analyzed blinded using a customized Praat program that computed intensity differences and slopes between vowel maxima and glottal stop minima for inter-[i] tokens and vowel maxima and voiceless consonant minima for intra-[isi] tokens. The number of voicing cessations for inter-[i] tokens was obtained.

RESULTS

Onset and offset intensity differences and number of voicing cessations from inter-[i] tokens had the greatest areas under the curve (.854, .856, and .835, respectively). Correlation coefficients were significant (p < .01) between AVQI and all GSP acoustic measures with weak/medium effect sizes. No significant differences were found between controls and participants with UVFP for acoustic measures from intra-[isi].

CONCLUSIONS

Acoustic GSP measures demonstrated good diagnostic accuracy and some relationship to severity of voice disorder. No significant differences in acoustic measures for medial voiceless fricative consonants between controls and participants with UVFP suggested that voicing cessation for voiceless fricatives differs from voicing cessation for GSP.

Therapeutic Singing and Semi-Occluded Vocal Tract Exercises for Individuals with Parkinson's Disease: A Randomized Controlled Trial of a Single Session Intervention

Individuals with Parkinson's disease (PD) experience speech and voice-related symptoms that diminish communication and quality of life. Semi-occluded vocal tract (SOVT) exercises are targeted interventions that, when combined with the positive psychosocial benefits of therapeutic group singing (TGS), may affect outcomes. The purpose of this study was to explore the effectiveness of SOVT exercises, specifically straw phonation combined with TGS, to improve voice quality and mood for individuals with PD. We used a true experimental pretest-posttest between-subjects design (i.e., randomized controlled trial) facilitated by a board-certified music therapist. All participants (N = 27) were randomly assigned to one of three groups (a) straw phonation combined with TGS (SP + TGS, n = 10), (b) TGS (n = 10), and (c) speaking-only control group (n = 7). Participants completed voice recordings for acoustic measures and the Visual Analogue Mood Scale for mood analysis before and after a 30-min intervention. The results demonstrated significant improvement in voice quality evidenced by decreasing Acoustic Voice Quality Index scores following a single session for both SP + TGS and TGS intervention groups when compared to the control. Happiness scores improved in the experimental groups when compared to control. Although not statistically significant, participants in the experimental groups (SP + TGS, TGS) demonstrated better mean mood scores on happiness, anxiety, and angry when compared to control, indicating a positive psychological response to the singing interventions. Overall, this study indicated the effectiveness of SP + TGS and TGS as promising therapeutic interventions for voice quality and mood in individuals with PD.

Towards Improved Auditory-Perceptual Assessment of Timbres: Comparing Accuracy and Reliability of Four Deconstructed Timbre Assessment Models

Timbre is a central quality of singing, yet remains a complex notion poorly understood in psychoacoustic studies. Previous studies note how no single acoustic variable or combinations of variables consistently predict timbre dimensions. Timbre varies on a continuum from darkest to lightest. These extremes are associated with laryngeal and vocal tract adjustments related to smaller and larger vocal tract area and variations in vocal fold vibratory characteristics. Perceptually, timbre assessment is influenced by spectral characteristics and formant frequency adjustments, though these dimensions are not independently perceived. Perceptual studies repeatedly demonstrate difficulties in correlating variations in timbre stimuli to specific measures. A recent study demonstrated how acoustic predictive salience of voice category and voice weight across pitches contribute to timbre assessments and concludes that timbre may be related to as-of-yet unknown factor(s). The purpose of this study was to test four different models for assessing timbre; one model focused on specific anatomy, one on listener intuition, one utilizing auditory anchors, and one using expert raters in a deconstructed timbre model with five specific dimensions.

METHODS

Four independent panels were conducted with separate cohorts of professional singing teachers. Forty-one assessors took part in the anatomically focused panel, 54 in the intuition-based panel, 30 in the anchored panel, and 12 in the expert listener panel. Stimuli taken from live performances of well-known singers were used for all panels, representing all genders, genres, and styles across a large pitch range. All stimuli are available as Supplementary Materials. Fleiss' kappa values, descriptive statistics, and significance tests are reported for all panel assessments.

RESULTS

Panels 1 through 4 varied in overall accuracy and agreement. The intuition-based model showed overall 45% average accuracy (SD ± 4%), k = 0.289 (<0.001) compared to overall 71% average accuracy (SD ± 3%), k = 0.368 (<0.001) of the anatomical focused panel. The auditory-anchored model showed overall 75% average accuracy (SD ± 8%), k = 0.54 (<0.001) compared with overall 83% average accuracy and agreement of k = 0.63 (<0.001) for panel 4. Results revealed that the highest accuracy and reliability were achieved in a deconstructed timbre model and that providing anchoring improved reliability but with no further increase in accuracy.

CONCLUSION

Deconstructing timbre into specific parameters improved auditory perceptual accuracy and overall agreement. Assessing timbre along with other perceptual dimensions improves accuracy and reliability. Panel assessors' expert level of listening skills remain an important factor in obtaining reliable and accurate assessments of auditory stimuli for timbre dimensions. Anchoring improved reliability but with no further increase in accuracy. The study suggests that timbre assessment can be improved by approaching the percept through a prism of five specific dimensions each related to specific physiology and auditory-perceptual subcategories. Further tests are needed with framework-naïve listeners, nonmusically educated listeners, artificial intelligence comparisons, and synthetic stimuli to further test the reliability.

Auditory-Perceptual Assessment and Acoustic Analysis of Gender Expression in the Voice

OBJECTIVE

Determine if acoustic measurements exist that are predictive of Auditory-Perceptual Assessment (APA) of gender expression in the voice of transgender, nonbinary, and cisgender Brazilian speakers by transgender, nonbinary, and cisgender judges, as well as speech-language pathologists in the area of voice studies.

METHODS

Cross-sectional study. Clips of speech (automatic speech and expressive reading of poetry) and sustained vowel emission of people of different genders were recorded and underwent APA for gender expression in the voice using a visual analog scale across 100 points, ranging from very masculine to very feminine. Sixteen acoustic measurements were extracted (noise, perturbation, spectral, and cepstral measurements). A descriptive and inferential analysis was performed using interclass coefficients of correlation and stepwise multiple linear regression, considering P < 0.05 for statistical significance.

RESULTS

Forty-seven people of different genders had their voices recorded. The perceived gender of these voices was judged by 236 people (65 speech-language pathologists, 101 cisgender people, and 70 transgender and nonbinary people). The perceptions and measurements that were predictive of gender perception in the voice differed according to the task (vowel or speech) and the group of judges. The predictive acoustic measurements that were common in all groups were: speech-median F0, harmonic-to-noise ratio (HNR), F0 standard deviation (F0sd), average width between F0 peaks, and spectral emphasis (Emph); vowels-median F0, HNR, F0sd, and average width between F0 peaks. Divergent measurements between groups were: speech-coefficient of variation of intensity, speech rate (Sr), minimum and maximum F0, jitter, and shimmer; vowels-coefficient of variation of intensity, Emph, Sr, and minimum and maximum F0.

CONCLUSION

There are acoustic measures that may predict APA; however, each group of judges considers different measures to evaluate gender, revealing an important influence of context on the evaluator in gender assessment through the voice.

Effect of Smoking on Cepstral Parameters

Smoking exerts certain damage to the voice, which affects sound characteristics. This study explored the effects of smoking, smoking time, and smoking amount on cepstral parameters. We collected the acoustic signals of sustained vowels in 301 participants (135 smokers and 166 nonsmokers). The cepstral parameters, including cepstral peak prominence (CPP), CPP standard deviation (CPP SD), low to high-frequency spectral ratio (L/H), low to high-frequency spectral ratio standard deviation (L/H SD), and voice disorder cepstral/spectral index of dysphonia (CSID), of the sustained vowels were investigated through the analysis of dysphonia in speech and voice (ADSV) application. The effects of smoking on these parameters were explored. The influences of smoking time and smoking amount on cepstral parameters were also analyzed by multiple linear regression. The CPP and L/H values in the smoking group were lower than those in the nonsmoking group (CPP: P < 0.001, L/H: P = 0.033) and negatively correlated with smoking time (CPP: R2 = 0.3828, P < 0.0001; L/H: R2 = 0.02996, P = 0.0447) and smoking amount (CPP: R2 < 0.4526, P < 0.0001; L/H: R2 = 0.08823, P = 0.00005). The CPP SD, L/H SD, and CSID values in the smoking group were higher than those in the nonsmoking group (CPP SD: P = 0.006, L/H SD: P = 0.034, CSID: P < 0.001) and positively correlated with smoking time (CPP SD: R2 = 0.03648, P = 0.0265, L/H SD: R2 = 0.09121, P = 0.0004, CSID: R2 = 0.01247, P = 0.1972) and smoking amount (CPP SD: R2 = 0.05495, P = 0.0062, L/H SD: R2 = 0.1316, P < 0.0001, CSID: R2 = 0.03851, P = 0.0225). Compared with other cepstral parameters, smoking time and smoking volume had the greatest impact on CPP (smoking time: R2 = 0.385, smoking amount: R2 = 0.443). This study confirmed that smoking has a significant effect on cepstral parameters. Compared with the cepstral parameters of nonsmokers, an increase in smoking time and smoking volume increases the abnormality of the cepstral parameters of smokers.

Accuracy Analysis of the Multiparametric Acoustic Voice Indices, the VWI, AVQI, ABI, and DSI Measures, in Differentiating between Normal and Dysphonic Voices

The study aimed to investigate and compare the accuracy and robustness of the multiparametric acoustic voice indices (MAVIs), namely the Dysphonia Severity Index (DSI), Acoustic Voice Quality Index (AVQI), Acoustic Breathiness Index (ABI), and Voice Wellness Index (VWI) measures in differentiating normal and dysphonic voices. The study group consisted of 129 adult individuals including 49 with normal voices and 80 patients with pathological voices. The diagnostic accuracy of the investigated MAVI in differentiating between normal and pathological voices was assessed using receiver operating characteristics (ROC). Moderate to strong positive linear correlations were observed between different MAVIs. The ROC statistical analysis revealed that all used measurements manifested in a high level of accuracy (area under the curve (AUC) of 0.80 and greater) and an acceptable level of sensitivity and specificity in discriminating between normal and pathological voices. However, with AUC 0.99, the VWI demonstrated the highest diagnostic accuracy. The highest Youden index equaled 0.93, revealing that a VWI cut-off of 4.45 corresponds with highly acceptable sensitivity (97.50%) and specificity (95.92%). In conclusion, the VWI was found to be beneficial in describing differences in voice quality status and discriminating between normal and dysphonic voices based on clinical diagnosis, i.e., dysphonia type, implying the VWI's reliable voice screening potential.

Latoszek B, Hunter EJ. Clinical Utility and Validation of the Acoustic Voice Quality and Acoustic Breathiness Indexes for Voice Disorder Assessment in English Speakers

BACKGROUND

While several acoustic voice metrics are available for clinical voice assessment, there remains a significant need for reliable and ecologically valid tools. The Acoustic Voice Quality Index version 03.01 (AVQI-3) and Acoustic Breathiness Index (ABI) hold potential due to their comprehensive assessment approach, incorporating diverse voice aspects. However, these tools still need to be validated in English-speaking populations.

METHODS

This study assessed the discriminatory accuracy and validity of AVQI-3 and ABI in 197 participants, including 148 with voice disorders. Voice samples were collected, followed by AVQI-3 and ABI calculations. Additionally, auditory-perceptual assessments were conducted by a panel of speech-language pathologists.

RESULTS

AVQI-3 and ABI effectively identified disordered voice quality, evidenced by high accuracy (AUCs: 0.84, 0.89), sensitivity, and specificity (thresholds: AVQI-3 = 1.17, ABI = 2.35). Strong positive correlations were observed with subjective voice quality assessments (rs = 0.72, rs = 0.77, p < 0.001).

CONCLUSIONS

The study highlights AVQI-3 and ABI as promising instruments for clinically assessing voice disorders in U.S. English speakers, underscoring their utility in clinical practice and voice research.

Smartphone-Based Voice Wellness Index Application for Dysphonia Screening and Assessment: Development and Reliability

OBJECTIVE

This study aimed to develop a Voice Wellness Index (VWI) application combining the acoustic voice quality index (AVQI) and glottal function index (GFI) data and to evaluate its reliability in quantitative voice assessment and normal versus pathological voice differentiation.

STUDY DESIGN

Cross-sectional study.

METHODS

A total of 135 adult participants (86 patients with voice disorders and 49 patients with normal voices) were included in this study. Five iOS and Android smartphones with the "Voice Wellness Index" app installed were used to estimate VWI. The VWI data obtained using smartphones were compared with VWI measurements computed from voice recordings collected from a reference studio microphone. The diagnostic efficacy of VWI in differentiating between normal and disordered voices was assessed using receiver operating characteristics (ROC).

RESULTS

With a Cronbach's alpha of 0.972 and an ICC of 0.972 (0.964-0.979), the VWI scores of the individual smartphones demonstrated remarkable inter-smartphone agreement and reliability. The VWI data obtained from different smartphones and a studio microphone showed nearly perfect direct linear correlations (r = 0.993-0.998). Depending on the individual smartphone device used, the cutoff scores of VWI related to differentiating between normal and pathological voice groups were calculated as 5.6-6.0 with the best balance between sensitivity (94.10-95.15%) and specificity (93.68-95.72%), The diagnostic accuracy was excellent in all cases, with an area under the curve (AUC) of 0.970-0.974.

CONCLUSION

The "Voice Wellness Index" application is an accurate and reliable tool for voice quality measurement and normal versus pathological voice screening and has considerable potential to be used by healthcare professionals and patients for voice assessment.

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

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

The use of basic fibroblast growth factor to improve vocal function: A systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis examines if intralaryngeal injection of basic fibroblast growth factor 2 (FGF2) can improve voice outcomes in those with vocal disability.

DESIGN

A Systematic review of original human studies reporting voice outcomes following intra-laryngeal injection of basic fibroblast growth factor 2 in those with vocal dysfunction. Databases searched were Medline (1946-July 2022), Embase (1947-July 2022), Cochrane database and Google Scholar.

SETTING

Secondary or tertiary care centres that undertook the management of voice pathology Hospital.

PARTICIPANTS

Inclusion criteria were original human studies reporting voice outcome measurements following intralaryngeal injection of FGF2 to treat vocal fold atrophy, vocal fold scarring, vocal fold sulcus or vocal fold palsy. Articles not written in English, studies that did not include human subjects and studies where voice outcome measures were not recorded before and after FGF2 injection were excluded from the review.

MAIN OUTCOME MEASURES

The primary outcome measure was maximum phonation time. Secondary outcome measures included acoustic analysis, glottic closure, mucosal wave formation, voice handicap index and GRBAS scale.

RESULTS

Fourteen articles were included out of a search of 1023 and one article was included from scanning reference lists. All studies had a single arm design without control groups. Conditions treated were vocal fold atrophy (n = 186), vocal cord paralysis (n = 74), vocal fold fibrosis (n = 74) and vocal fold sulcus (n = 56). A meta-analysis of six articles reporting on the use of FGF2 in patients with vocal fold atrophy showed a significant increase of mean maximum phonation time of 5.2 s (95% CI: 3.4-7.0) at 3-6 months following injection. A significant improvement in maximum phonation time, voice handicap index and glottic closure was found following injection in most studies assessed. No major adverse events were reported following injection.

CONCLUSIONS

To date, intralaryngeal injection of basic FGF2 appears to be safe and it may be able to improve voice outcomes in those with vocal dysfunction, especially vocal fold atrophy. Randomised controlled trials are needed to further evaluate efficacy and support the wider use of this therapy.

Advances in Clinical Voice Quality Analysis with VOXplot

BACKGROUND

The assessment of voice quality can be evaluated perceptually with standard clinical practice, also including acoustic evaluation of digital voice recordings to validate and further interpret perceptual judgments. The goal of the present study was to determine the strongest acoustic voice quality parameters for perceived hoarseness and breathiness when analyzing the sustained vowel [a:] using a new clinical acoustic tool, the VOXplot software.

METHODS

A total of 218 voice samples of individuals with and without voice disorders were applied to perceptual and acoustic analyses. Overall, 13 single acoustic parameters were included to determine validity aspects in relation to perceptions of hoarseness and breathiness.

RESULTS

Four single acoustic measures could be clearly associated with perceptions of hoarseness or breathiness. For hoarseness, the harmonics-to-noise ratio (HNR) and pitch perturbation quotient with a smoothing factor of five periods (PPQ5), and, for breathiness, the smoothed cepstral peak prominence (CPPS) and the glottal-to-noise excitation ratio (GNE) were shown to be highly valid, with a significant difference being demonstrated for each of the other perceptual voice quality aspects.

CONCLUSIONS

Two acoustic measures, the HNR and the PPQ5, were both strongly associated with perceptions of hoarseness and were able to discriminate hoarseness from breathiness with good confidence. Two other acoustic measures, the CPPS and the GNE, were both strongly associated with perceptions of breathiness and were able to discriminate breathiness from hoarseness with good confidence.

Reliability of Universal-Platform-Based Voice Screen Application in AVQI Measurements Captured with Different Smartphones

The aim of the study was to develop a universal-platform-based (UPB) application suitable for different smartphones for estimation of the Acoustic Voice Quality Index (AVQI) and evaluate its reliability in AVQI measurements and normal and pathological voice differentiation. Our study group consisted of 135 adult individuals, including 49 with normal voices and 86 patients with pathological voices. The developed UPB "Voice Screen" application installed on five iOS and Android smartphones was used for AVQI estimation. The AVQI measures calculated from voice recordings obtained from a reference studio microphone were compared with AVQI results obtained using smartphones. The diagnostic accuracy of differentiating normal and pathological voices was evaluated by applying receiver-operating characteristics. One-way ANOVA analysis did not detect statistically significant differences between mean AVQI scores revealed using a studio microphone and different smartphones (F = 0.759; p = 0.58). Almost perfect direct linear correlations (r = 0.991-0.987) were observed between the AVQI results obtained with a studio microphone and different smartphones. An acceptable level of precision of the AVQI in discriminating between normal and pathological voices was yielded, with areas under the curve (AUC) displaying 0.834-0.862. There were no statistically significant differences between the AUCs (p > 0.05) obtained from studio and smartphones' microphones. The significant difference revealed between the AUCs was only 0.028. The UPB "Voice Screen" application represented an accurate and robust tool for voice quality measurements and normal vs. pathological voice screening purposes, demonstrating the potential to be used by patients and clinicians for voice assessment, employing both iOS and Android smartphones.

Evidence on Vocal Interventions in Adults: A Scoping Review

OBJECTIVE

To map the evidence on vocal intervention in people over 18 years old.

METHODS

A literature search was conducted using the following electronic databases: Cochrane Library, EMBASE, Latin American and Caribbean Literature on Health Sciences (LILACS), LIVIVO, Pubmed/Medline, Scopus, SpeechBITE, and Web of Science. Gray literature was also used as an information source through searches on Google Scholar, Open Grey, ProQuest Dissertation and Thesis, and the Brazilian digital library of theses and dissertations. Systematic reviews (SR) with a population of individuals over 18 years old were included. The included reviews addressed speech-language pathology interventions in the vocal area with reports of their respective outcome. The methodological quality of the included systematic reviews was analyzed using the AMSTAR II tool. Quantitative analysis was performed by frequency distribution, and qualitative research was analyzed through narrative synthesis.

RESULTS

A total of 2,443 references were retrieved, among which 20 studies met the inclusion criteria. The included studies had critically low quality, lacking the use of population, intervention, comparison, and outcome (PICO) components. Among the included SRs, 40% were made in Brazil, 45% were published in the Journal of Voice, and 75% analyzed dysphonic patients. The most frequent intervention was voice therapy (direct therapy associated with indirect therapy approaches). Positive results were observed in most of the outcomes for all studies.

CONCLUSION

Voice therapy was described as inducing positive effects for voice rehabilitation. However, due to the critically low quality of studies, the literature did not enable us to understand the best results for each intervention. Well-designed studies are necessary to clarify the relationship between the intervention goal and how the intervention was evaluated.

Vocal Fatigue Index in Finnish-Speaking Population

BACKGROUND AND OBJECTIVE

Vocal fatigue is an important complaint that may indicate a voice disorder or a risk thereof. There is a need for a reliable tool to detect and quantify vocal fatigue and distinguish dysphonic and vocally healthy speakers. The Vocal Fatigue Index (VFI) questionnaire has been found valid and reliable among speakers of different languages. This study aims to validate it for speakers of Finnish.

STUDY DESIGN

Experimental comparative study.

METHODS

The VFI questionnaire was translated from English to Finnish according to the WHO recommendations. Next, it was subjected to the validation procedure. In total, 160 Finnish speakers volunteered to participate in the study. Hundred-and-eight were voice patients (83 males, 25 females) and 52 were vocally healthy controls (37 females, 15 males). As a comparison, the Voice Handicap Index (VHI) questionnaire was completed and voice samples were recorded to enable Acoustic Voice Quality Index (AVQI03.01_FIN) analysis.

RESULTS

Results from the first and second completions of the VFI(F) questionnaire correlated strongly (Spearman's rho 0.901, P = 0.01). Answers to the individual questions the VFI(F) also correlated strongly, showing high internal consistency. Factor 1 (Tiredness of voice and avoidance of voice use) of the VFI correlated strongly with the VHI, and the two other factors (Physical discomfort associated with voicing and Improvement of symptoms) correlated moderately with the VHI. Factor one of the VFI(F) correlated moderately with AVQI03.01_FIN and its sub-parameters, CPPS, HNR, and shimmer. The VFI(F) showed good construct validity, differentiating voice patients and controls at cut-off 13.5, with sensitivity of 0.963 and specificity of 0.885. Discriminatory power was strong for all factors: F1 A_ROC = 0.985, F2 A_ROC = 0.864, and F3 A_ROC = 0.821.

CONCLUSION

The VFI(F) correlates with the VHI and with AVQI01.01_FIN and it is a valid and reliable tool for detecting vocal fatigue in Finnish speakers.

An iOS-based VoiceScreen application: feasibility for use in clinical settings-a pilot study

OBJECTIVES

To elaborate the application suitable for smartphones for estimation of Acoustic Voice Quality Index (AVQI) and evaluate its usability in the clinical setting.

METHODS

An elaborated AVQI automatization and background noise monitoring functions were implemented into a mobile "VoiceScreen" application running the iOS operating system. A study group consisted of 103 adult individuals with normal voices (n = 30) and 73 patients with pathological voices. Voice recordings were performed in the clinical setting with "VoiceScreen" app using iPhone 8 microphones. Voices of 30 patients were recorded before and 1 month after phonosurgical intervention. To evaluate the diagnostic accuracy differentiating normal and pathological voice, the receiver-operating characteristic statistics, i.e., area under the curve (AUC), sensitivity and specificity, and correct classification rate (CCR) were used.

RESULTS

A high level of precision of AVQI in discriminating between normal and dysphonic voices was yielded with corresponding AUC = 0.937. The AVQI cutoff score of 3.4 demonstrated a sensitivity of 86.3% and specificity of 95.6% with a CCR of 89.2%. The preoperative mean value of the AVQI [6.01(SD 2.39)] in the post-phonosurgical follow-up group decreased to 2.00 (SD 1.08). No statistically significant differences (p = 0.216) between AVQI measurements in a normal voice and 1-month follow-up after phonosurgery groups were revealed.

CONCLUSIONS

The "VoiceScreen" app represents an accurate and robust tool for voice quality measurement and demonstrates the potential to be used in clinical settings as a sensitive measure of voice changes across phonosurgical treatment outcomes.

What Are the Contemporary Trends on Euphonic Voice Research? A Scientometric Analysis

(1) Background: The study of the human euphonic voice is a subject that has been researched in recent years from different perspectives. Therefore, it is pertinent to assess the current state of the science. The aim of analyzing the characteristics of normal voice-related publications over the last 11 years is to identify research trends, the numerical and temporal evolution of the publications, their type, and the most-used descriptors. (2) Methods: Bibliometric data from 2011 to 2021 were obtained through several databases. Subsequently, a science mapping analysis was made via VOSviewer software. (3) Results: A total of 901 publications were obtained. The analysis of the scientific production on the field of study regarding the euphonic voice shows a slight increase over the last 11 years, with an average of 82 publications per year. Co-authorship analysis revealed a 6215 authors contributing to the field with a 901 articles (headed by Jiang, J.J. with 18 articles). Keyword co-occurrence analysis highlighted the lack of temporal advancement and variety in the terminology used in the field of voice research. (4) Conclusions: This scientometric study sheds light to the need to broaden in this field of study and the establishment of solid research groups to contribute to its advancement.