The Efficacy of the Manual Circumlaryngeal Therapy for Muscle Tension Dysphonia: A Systematic Review and Meta-analysis.

OBJECTIVE: Muscle tension dysphonia (MTD) is the most common functional voice disorder. Behavioral voice therapy is the front-line treatment for MTD, and laryngeal manual therapy may be a part of this treatment. The objective of this study was to investigate the effect of manual circumlaryngeal therapy (MCT) on acoustic markers of voice quality (jitter, shimmer, and harmonics-to-noise ratio) and vocal function (fundamental frequency) through a systematic review with meta-analysis. DATA SOURCES: Four databases were searched from inception to December 2022, and a manual search was performed. REVIEW METHODS: The PRISMA extension statement for reporting systematic reviews incorporating a meta-analysis of health care interventions was applied, and a random effects model was used for the meta-analyses. RESULTS: We identified 6 eligible studies from 30 studies (without duplicates). The MCT approach was highly effective on acoustics with large effect sizes (Cohen's d > 0.8). Significant improvements were obtained in jitter in percent (mean difference of -.58; 95% CI -1.00 to 0.16), shimmer in percent (mean difference of -5.66; 95% CI -8.16 to 3.17), and harmonics-to-noise ratio in dB (mean difference of 4.65; 95% CI 1.90-7.41), with the latter two measurements continuing to be significantly improved by MCT when measurement variability is considered. CONCLUSION: The efficacy of MCT for MTD was confirmed in most clinical studies by assessing jitter, shimmer, and harmonics-to-noise ratio related to voice quality. The effects of MCT on the fundamental frequency changes could not be verified. Further contributions of high-quality randomized control trials are needed to support evidence-based practice in laryngology. Laryngoscope, 134:18-26, 2024.

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.

The Impact of Protective Face Coverings on Acoustic Markers in Voice: A Systematic Review and Meta-Analysis.

BACKGROUND: Wearing respiratory protective masks (RPMs) has become common worldwide, especially in healthcare settings, since the onset of the COVID-19 pandemic. Hypotheses have suggested that sound transmission could be limited by RPMs, which possibly affects the characteristics of acoustic energy and speech intelligibility. The objective of this study was to investigate the effect of RPMs on acoustic measurements through a systematic review with meta-analysis. METHODS: Five database searches were conducted, ranging from their inception to August 2023, as well as a manual search. Cross-sectional studies were included that provided data on widely used gender-independent clinical acoustic voice quality measures (jitter, shimmer, HNR, CPPS, and AVQI) and habitual sound pressure level (SPL). RESULTS: We found nine eligible research studies with a total of 422 participants who were compared both without masks and with different types of masks. All included studies focused on individuals with vocally healthy voices, while two of the studies also included those with voice disorders. The results from the meta-analysis were related to medical/surgical and FFP2/(K)N95 masks. None of the acoustic measurements showed significant differences between the absence and presence of masks (p > 0.05). When indirectly comparing both mask types, statistical significance was identified for parameters of jitter, HNR, CPPS and SPL (p < 0.001). CONCLUSIONS: The present meta-analysis indicates that certain types of RPMs have no significant influence on common voice quality parameters and SPL compared to recordings without masks. Nevertheless, it is plausible that significant differences in acoustic parameters might exist between different mask types. Consequently, it is advisable for the clinical practice to always use the same mask type when using RPMs to ensure high comparability and accuracy of measurement results.

Validation of the Acoustic Voice Quality Index and the Acoustic Breathiness Index in the Persian Language.

OBJECTIVES/HYPOTHESIS: This study aimed to validate the acoustic voice quality index version 03.01 (AVQIv3) and the acoustic breathiness index (ABI) in the Persian language. METHODS: Six judges assessed the severity degree of the abnormal overall voice quality (hoarseness) and breathiness from continuous speech (cs) and sustained vowel (sv) in 136 voices samples of dysphonic and 45 vocally healthy participants. Firstly, the time length of cs and sv was balanced out for a higher level of ecological validity. Secondly, the concurrent validity and diagnostic accuracy were statistically analyzed with the Spearman rank-order correlation, and the receiver operating characteristics, likelihood ratio, and Youden index. RESULTS: There was substantial inter-rater reliability between judges regarding hoarseness and breathiness. Twenty syllables were identified as the standardized number of syllables for the cs part. Sufficient correlations were found between AVQI and hoarseness (rs = 0.74), and between ABI and breathiness (rs = 0.74), respectively. The thresholds of 1.63 (sensitivity of 73.2% and specificity of 91%) and 2.97 (sensitivity of 70% and specificity of 87%) yielded the highest level of diagnostic findings for AVQI and ABI, respectively. CONCLUSION: The AVQIv3 and ABI are reliable indices to quantify the abnormal overall voice quality and breathiness in the Persian language.

Test-Retest Reliability of the Acoustic Voice Quality Index and the Acoustic Breathiness Index.

OBJECTIVE: The acoustic voice quality index (AVQI) and the acoustic breathiness index (ABI) are two validated measurements for the objective-acoustic assessment of voice quality. The aim of this study was to evaluate the relative and absolute reliability of AVQI and ABI as well as detect the natural variability of vocally-healthy voices. METHODS: Totally, 39 vocally-healthy participants received weekly an AVQI- and ABI measurement using the freeware VOXplot over a period of 3 weeks. This study is a within-subject design to assess significant differences between the test and retest measurements (test and mean of two retests) of AVQI and ABI with the paired sample t test and to investigate the reliability of these two acoustic parameters with the intraclass correlation coefficient (ICC), Bland-Altman plot, and the minimal detectable change (MDC). RESULTS: No significant differences between the test-retest measurements of AVQI and ABI were revealed (all P-values > 0.05). The relative reliability of AVQI and ABI showed good results (eg, ICC = 0.81, and ICC = 0.92, respectively). Absolute reliability measured with the MDC yielded a test-retest value of 0.78 and 0.66 for the AVQI and ABI, respectively. Deviations within this range may be due to natural variations of the voice (random bias). CONCLUSION: AVQI and ABI revealed high-reliability results in a test-retest measurement of vocally-healthy participants.

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.

The Efficacy of Different Voice Treatments for Vocal Fold Polyps: A Systematic Review and Meta-Analysis.

BACKGROUND: Vocal fold polyps (VFP) are a common cause of voice disorders and laryngeal discomfort. They are usually treated by behavioral voice therapy (VT) or phonosurgery, or a combination (CT) of both. However, the superiority of either of these treatments has not been clearly established. METHODS: Three databases were searched from inception to October 2022 and a manual search was performed. All clinical trials of VFP treatment were included that reported at least auditory-perceptual judgment, aerodynamics, acoustics, and the patient-perceived handicap. RESULTS: We identified 31 eligible studies (VT: n = 47-194; phonosurgery: n = 404-1039; CT: n = 237-350). All treatment approaches were highly effective, with large effect sizes (d > 0.8) and significant improvements in almost all voice parameters (p-values < 0.05). Phonosurgery reduced roughness and NHR, and the emotional and functional subscales of the VHI-30 were the most compared to behavioral voice therapy and combined treatment (p-values < 0.001). Combined treatment improved hoarseness, jitter, shimmer, MPT, and the physical subscale of the VHI-30 more than phonosurgery and behavioral voice therapy (p-values < 0.001). CONCLUSIONS: All three treatment approaches were effective in eliminating vocal fold polyps or their negative sequelae, with phonosurgery and combined treatment providing the greatest improvement. These results may inform future treatment decisions for patients with vocal fold polyps.

The Performance of the Acoustic Voice Quality Index and Acoustic Breathiness Index in Synthesized Voices.

OBJECTIVE: The aim of the present study was to investigate the performance of the Acoustic Voice Quality Index (AVQI) and the Acoustic Breathiness Index (ABI) in synthesized voice samples. METHOD: The validity of the AVQI and ABI performances was analyzed in synthesized voice samples controlling the degree of predefined deviations for overall voice quality (G-scale) and breathiness (B-scale). A range of 26 synthesized voice samples with various severity degrees in G-scale with and without prominence of breathiness for male and female voices were created. RESULTS: ABI received higher validity in the evaluation of breathiness than AVQI. Furthermore, ABI evaluated accurately breathiness degrees without considering roughness effects in voice samples and confirmed the findings of other studies with natural voices. Furthermore, ABI was more robust than AVQI in the evaluation of severe voice-disordered voice samples. Finally, AVQI represented moreover overall voice quality with an emphasis of breathiness evaluation and less roughness although roughness had a necessary component in overall voice quality evaluation. CONCLUSION: AVQI and ABI are two robust measurements in the evaluation of voice quality. However, ABI received fewer errors than AVQI in the analyses of higher abnormalities in the voice signal. Disturbances of other subtypes of abnormal overall voice quality such as roughness were not demonstrated in the results of ABI.

The German Restructured Vocal Fatigue Index and Characteristics of Dysphonic and Vocally Healthy Populations.

OBJECTIVE: The Vocal Fatigue Index (VFI), a 19-item psychometric self-report questionnaire, enables individuals with vocal fatigue (VF) to be identified and their complaints to be characterized. The purpose of this study was to improve the German-language version (VFI-G) and to evaluate further vocal fatigue-related characteristics of dysphonic and control populations. METHODS: The VFI-G was restructured by replacing the three factors that structured the original: (1) tiredness of voice and voice avoidance; (2) physical discomfort; and (3) improvement of symptoms with rest, with two clusters developed on the basis of the results of a factor analysis by Nanjundeswaran et al. (2019). The two new clusters are: (1) tiredness and avoidance plus physical discomfort; and (2) symptom improvement through rest. One hundred one (101) individuals with voice disorders and 100 vocally healthy controls from a previous study that cross-validated the VFI-G participated in this study. In order to assess the validity of our newly adjusted VFI-G, independent samples t test, receiver operating characteristic curve, likelihood ratios and the Youden Index were calculated. The association of the two VF clusters with subject characteristics such as age, sex, type of voice disorder, and level of vocal usage was also analyzed using either a Pearson correlation or a one-way ANOVA for each of the two populations. RESULTS: Significantly higher scores were obtained in voice-disordered subjects in both clusters (all P values < 0.001) than in healthy-voice subjects. The threshold for cluster 1 of the VFI-G was determined as ≥17.5 (74.3% sensitivity and 88.0% specificity). The results of cluster 2 are identical to that of factor 3 of the previous cross-validation study of the VFI-G. Most subject characteristics show no significant association with cluster 1 of the VFI-G, but cluster 2 seems to be moderately associated with age, type of voice disorder and level of vocal usage in the dysphonic population. CONCLUSIONS: The restructured VFI-G showed improved validity and can be recommended for use in the assessment of VF. Cluster 2 is also moderately associated with several vocal fatigue-related subject characteristics of the dysphonic population.

The maximum phonation time as marker for voice treatment efficacy: A network meta-analysis.

PURPOSE: There is a diversity in treatment approaches for voice therapy in which aerodynamic treatment effects between the approaches are lacking. The evidence of voice treatments on the maximum phonation time (MPT) was quantified using the statistical approach of a network meta-analysis (NMA). DATA SOURCES: Three databases and manual search from inception to November 2021 were evaluated. STUDY SELECTION: Studies were considered which were reports of randomised controlled/clinical trials (RCT) evaluating the efficacy of a specific voice therapy treatment using MPT as an outcome measure in adult participants with voice disorders. Studies were excluded if participants had been diagnosed with neurological-motor-speech disorders or who were vocally healthy. Furthermore, no medical, pharmacological, or technical instrumental treatments were used. DATA EXTRACTION AND SYNTHESIS: Preferred Reporting Items for systematic reviews and meta-analyses extension statement guidelines were followed. Two reviewers independently screened citations, extracted data, and assessed risk of bias using PEDro scale. Random effects model was used for meta-analysis. RESULTS: We identified finally 12 RCT studies (treatment groups n = 285, and control group without an intervention n = 62). Eight interventions were evaluated. The only effective intervention with a significant effect was vocal function exercises (VFE) (mean pre-post difference 6.16 s, 95% confidence interval, 1.18-11.13 s). CONCLUSIONS AND RELEVANCE: VFE effectively improved MPT from pre- to post-treatment in comparison with other voice interventions which were identified in the present NMA. Further high-quality intervention studies with large samples sizes, multidimensional measures, and homogeneous groups of dysphonia are needed to support evidence-based practice in laryngology.

Validation of the acoustic breathiness index to the Brazilian Portuguese language.

OBJECTIVE: To assess the concurrent validity and the diagnostic accuracy of the Acoustic Breathiness Index (ABI) in Brazilian Portuguese. METHODS: The counting numbers 1-20 and the vowel /a/ of 150 subjects were recorded (37 vocally healthy and 113 with dysphonia). The analyzed samples were the counting number 1-11 and 3 s of the sustained vowel. Nine voice specialists performed the perceptual judgment of the degree of breathiness. The Spearman Correlation and the receiver operating characteristic (ROC) curve were used to assess ABI's concurrent validity and diagnosis accuracy. RESULTS: Results from five listeners were chosen for the study analyses due to moderate and substantial intra-rater reliability (Cohen's Kappa values = 0.520-0.772) and moderate inter-rater reliability (Fleiss Kappa = 0.353). The ABI presented a high concurrent validity (r = 0.746); 55.6% of the breathiness vocal deviation can be explained by the acoustic analysis (r2 = 0.556). The ROC curve presented good diagnostic accuracy (85.2%). At a threshold of 2.94, the sensitivity was 75.3% and the specificity was 93.4%. CONCLUSION: The ABI is a valid tool for screening and patient's follow-up regarding breathy vocal qualities in the Brazilian Portuguese language.

The cepstral spectral index of dysphonia, the acoustic voice quality index and the acoustic breathiness index as novel multiparametric indices for acoustic assessment of voice quality.

PURPOSE OF REVIEW: The objective assessment of voice quality using acoustic measures is an important pillar of voice diagnostics. This article reviews three recent acoustic measures and their clinical use in phoniatrics and laryngology. RECENT FINDINGS: Two acoustic parameters, the cepstral spectral index of dysphonia (CSID) and the acoustic voice quality index (AVQI), have gained importance as validated multiparametric indices in the objective assessment of hoarseness because they include both continuous speech and sustained vowels. The acoustic breathiness index (ABI), another multiparametric index, assesses breathiness admixture during phonation and identifies it robustly, unaffected by other characteristics of dysphonia such as roughness. SUMMARY: Acoustic measurements are useful diagnostic tools when used correctly with an appropriate recording system, consideration of environment and use of software programs. CSID, AVQI and ABI objectively improve the detection of voice quality abnormalities. In addition to their proven validity, their application is simple and their usability for clinicians is high.

The validity of the Acoustic Breathiness Index in the evaluation of breathy voice quality: A Meta-Analysis.

BACKGROUND: The evaluation of voice quality with acoustic measurements is useful to objectify the diagnostic process. Particularly, breathiness was highly evaluated and the Acoustic Breathiness Index (ABI) might have promising features. OBJECTIVE OF REVIEW: The goal of the present meta-analysis is to quantify, from existing cross-validation studies, the evidence for the diagnostic accuracy of ABI, including its sensitivity and specificity. TYPE OF REVIEW: Meta-analysis. SEARCH STRATEGY: We searched in MEDLINE, Google Scholar and Science Citation Index, and as manual search for the term Acoustic Breathiness Index from inception to February 2020. Studies were included that used equal proportion of continuous speech and sustained vowel segments, a recording hardware with a sufficient standard for voice signal analyses, the software Praat for signal processing and the customised Praat script, and two groups of subjects (vocally healthy and voice-disordered). Furthermore, the diagnostic accuracy of ABI was measured. EVALUATION METHOD: The primary outcome variable was ABI. The score ranged from 0 to 10 with varying thresholds according to different languages to determine the absence or presence of breathiness. A meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses of diagnostic test accuracy study guidelines. Data were extracted, and the risk of bias was assessed using the QUADAS-2 tool. The pooled sensitivity and specificity of ABI were determined using a summary receiver operating characteristic (SROC) approach to calculate also a weighted threshold value of ABI with its sensitivity and specificity. RESULTS: A total of 34 unique citations were screened, and 10 full-text articles were reviewed, including six studies. In total, 3603 voice samples were considered for further analysis separating into 467 vocally healthy and 3136 voice-disordered voice samples. The pooled sensitivity was 0.84 (95% CI, 0.83-0.85), and the pooled specificity was 0.92 (95% CI, 0.89-0.94). The area under the curve of the SROC curve of this analysis showed an excellent value of 0.94. The weighted ABI threshold was determined at 3.40 (sensitivity: 0.86, 95% CI, 0.84-0.87.; specificity: 0.90, 95% CI 0.88-0.92). CONCLUSIONS: The results confirm the ABI as robust and valid objective measure for evaluating breathiness.

A Case of Nervus Laryngeus Superior Paresis Treated With Novafon Local Vibration Voice Therapy.

OBJECTIVE: The aim of the study is to present a case of chronic idiopathic superior laryngeal nerve paresis (SLNp) treated with a novel voice therapy approach called Novafon Local Vibration Voice Therapy (NLVVT). METHODS: Outcome measurements including acoustics, aerodynamics, and self-perception of voice handicap were acquired before intervention (i.e., NLVVT) and after intervention (i.e.,follow-up). The use of NLVVT was modified from previous reports of use in functional voice disorders for application to a neurological voice disorder (SLNp). RESULTS: The results showed that NLVVT had meaningful improvements in Voice Range Profile boundaries, an increase in speaking fundamental frequency, and improved acoustic indices of voice quality in a case of SLNp. The follow-up after NLVVT intervention revealed maintenance of the post-treatment improvements at a 1-month measurement interval. CONCLUSION: The NLVVT program may have potential to improve voice quality and vocal function in a case of SLNp. Further research is necessary to test a potential effectiveness for NLVVT applied to vocal fold immobility due to paresis in both larger numbers of patients and more well-designed, controlled experiments.

Validation of the Acoustic Voice Quality Index, Version 03.01, to the Brazilian Portuguese Language.

INTRODUCTION: Multiparametric indexes provide a more robust acoustic analysis of voice quality considering more than one acoustic parameter in the evaluation of sustained phonation and continuous speech. However, once the continuous speech is considered, differences among languages must be addressed. OBJECTIVE: To assess the concurrent validity and the diagnostic accuracy of the Acoustic Voice Quality Index version 03.01 (AVQI 03.01) in the Brazilian Portuguese. METHOD: The counting numbers 1-20 and the vowel /a/ of 150 subjects were used (37 nondysphonic; 113 with dysphonia). To reach higher precision of the AVQI, the length of the voiced parts of the continuous speech and the sustained vowel were equalized. Nine voice specialists performed the perceptual auditory judgment of the samples. However, only five listeners were chosen for further analysis based on their moderate to substantial intrarater reliability (Cohen's Kappa: 0.605-0.773) and their reasonable inter-rater reliability (Fleiss Kappa: 0.429). The index concurrent validity and diagnosis accuracy were analyzed with the Spearman correlation and the receiver-operating characteristic curve. RESULTS: The AVQI 03.01 concurrent validity was high (r = 0.716). The coefficient of determination demonstrated that 51% of the vocal deviation can be explained by the acoustic analysis (r2 = 0.512). The diagnostic accuracy was excellent (90.4%). At a threshold of 1.33, the AVQI sensitivity and specificity were 78.8% and 90.6%, respectively. CONCLUSION: The AVQI is a valid tool in the Brazilian Portuguese language. It can be used as a screening tool, for clinical follow-up and evaluation pre- and post-treatment/procedures. Voice specialist should be aware of false-negative and false-positive results of the AVQI, especially for screening purposes.

Cross-Cultural Adaption and Validation of the Vocal Fatigue Index in German.

OBJECTIVE: The purpose of the study was to implement a cross-validation and adaption of the Vocal Fatigue Index (VFI) in German language. METHODS: The translation process for the German version (GV) of the VFI passed through three steps of translation before a final version was completed. Study subjects included 100 vocally healthy subjects and 101 voice-disordered subjects with various types of dysphonia. The internal consistency was determined using Cronbach's alpha (cron α) and the item-total analysis. Test-retest reliability was measured with the Pearson correlation coefficient. To assess the validity, the independent sample t test, the receiver-operating characteristic curve, the likelihood ratios, and Youden Index were used. RESULTS: The internal consistency across all three domains were good (#1: cron α = 0.945, #2: cron α = 0.904, and #3: cron α = 0.871) and no item of the GV of the VFI had to be deleted for further analysis relating to the item-total analysis. The test-retest reliability was high to very high (r = 0.86-0.93). Significant higher scores were revealed in voice-disordered subjects in comparison with vocally healthy subjects in all three domains (all Pvalues <0.01). Thresholds for the three domains of the GV of the VFI were determined at ≥15.5 (76.2% sensitivity and 90.0% specificity) for #1, ≥2.5 (71.5% sensitivity and 81.0% specificity) for #2, and ≤7.5 (50.5% sensitivity and 80.0% specificity) for #3. CONCLUSIONS: It can be considered that the VFI is a valid and reliable tool identifying vocal fatigue symptoms and its severity in the German-speaking population.

The effectiveness of voice therapy on voice-related handicap: A network meta-analysis.

BACKGROUND: Treatment approaches for voice therapy are diverse, yet their differential effects are not well understood. Evaluations of treatment effects across approaches are important for clinical guidance and evidence-based practice. OBJECTIVE OF REVIEW: To quantify the evidence of treatment effectiveness on the outcome measure Voice Handicap Index with the 30-items (VHI-30) from existing randomised controlled/clinical trials (RCT) of voice therapy using the statistical approach of a network meta-analysis (NMA) with a random effects model. TYPE OF REVIEW: Meta-analysis. SEARCH STRATEGY: We searched in MEDLINE (PubMed, 1950 to 2019), Embase (1974 to 2019) and Science Citation Index (1994 to 2019) using five key terms. The inclusion criteria were reports of randomised controlled/clinical trials (RCTs) published in English or German which evaluated the effectiveness of a specific voice therapy treatment using VHI-30 as an outcome measure in adult participants with non-organic or organic voice disorders. Studies were excluded if participants had been diagnosed with neurological motor speech disorders or who were vocally healthy. Furthermore, no medical, pharmacological or instrumental (eg voice amplification) treatments were considered. EVALUATION METHOD: The primary outcome variable was VHI-30 with a score from 0 to 120. The pre-post treatment change in VHI-30 scores was an average score of 13 points related to various VHI-30 test-retest results. RESULTS: We retrieved 464 publications (ie with duplicates) and included 13 RCTs, which evaluated nine interventions, in the final analysis. The most effective intervention with a significant and clinically relevant effect was Stretch-and-Flow Phonation (SFP) (mean pre-post difference -28.37, 95% confidence interval [CI], -43.05 to-13.68). Resonant Voice (RV), the Comprehensive Voice Rehabilitation Program (CVRP) and Vocal Function Exercises (VFE) also demonstrated significant improvements. CONCLUSIONS: Of the nine voice interventions identified with the present NMA, SFP, RVT, CVRP, and VFE effectively improved VHI-30 scores from pre- to post-treatment. SFP proved to be the most significant and clinically relevant treatment. Further contributions of high-quality intervention studies are needed to support evidence-based practice in vocology.

Treatment Effectiveness of Novafon Local Vibration Voice Therapy for Dysphonia Treatment.

BACKGROUND: The objective of this study was to explore the effectiveness of the five-week Novafon local vibration voice therapy (NLVVT) program with and without Novafon local vibration for dysphonia treatment. METHODS: Twenty-two voice-disordered subjects were divided into two groups. The intervention group (IG) performed the NLVVT program and the control group (CG) had the same voice exercises of this program without local vibration. RESULTS: After NLVVT, the IG showed significantly high results in all parameters of acoustics, multiparametric indices, and self-evaluation (all P values < 0.01). The CG revealed mostly much significantly lower results (P values < 0.05) or nonsignificant results for these parameters after the treatment. The intergroup comparison under consideration before and after NLVVT showed a large and significant treatment effect in voice quality (ie, narrowband spectrograms, and Acoustic Voice Quality Index), in which the IG had better treatment results. The aerodynamic measurement showed no significant changes for both groups after NLVVT (P value > 0.05). CONCLUSION: After the NLVVT program both groups showed significant improvements of various voice measurements, in which the IG revealed better treatment results than the CG. However, next to voice exercises an extra benefit for local vibration with the Novafon appliance was assessed in voice quality.

Validation of the Acoustic Voice Quality Index Version 03.01 and Acoustic Breathiness Index in German.

OBJECTIVE: The aim of this study was to validate the acoustic voice quality index (AVQI) version 03.01 and the acoustic breathiness index (ABI) in the German language. METHODS: Concatenated voice samples of continuous speech (cs) and sustained vowel (sv) [a:] from 175 subjects with dysphonia and 43 vocally healthy subjects were perceptually judged for overall voice quality and breathiness severity. First, to reach a higher level of ecological validity, the proportions of cs and sv were equalized regarding the time length. Second, concurrent validity and diagnostic accuracy were statistically verified using the Spearman rank-order correlation coefficient (rs) and several estimates of the receiver operating characteristics, likelihood ratio, and Youden index. RESULTS: A moderate reliability of overall voice quality and breathiness severity from three experts were found. It was found that 27 syllables as standardization of the cs part, which represents 3 seconds of voiced cs, allows the equalization of both speech tasks. A strong correlation was revealed between AVQI and overall voice quality (rs = 0.86, P < 0.01), and ABI and perceived breathiness severity (rs = 0.85, P < 0.01). Additionally, the best diagnostic outcome for AVQI and ABI was identified at a threshold of 1.85 (sensitivity of 72 % and specificity of 90 %) and 3.42 (sensitivity of 72 % and specificity of 95 %), respectively. CONCLUSION: AVQI and ABI showed in the German language valid and robust results to quantify abnormal voice qualities regarding overall voice quality and breathiness severity.

The acoustic voice quality index version 02.02 in the Finnish-speaking population.

Background: The Acoustic Voice Quality Index (AVQI) is a multiparametric tool for objectively measuring the general acoustic characteristics of voice. The AVQI uses both sustained vowel and continuous speech in its analysis, and therefore, a validation is required for different languages. In the present study, validation was performed in the Finnish-speaking population.Methods: The study included 200 native Finnish-speaking participants of whom 115 were voice patients attending a phoniatric clinic, and the remaining 85 subjects participated in the study as healthy controls. Voice samples were recorded, and the auditory evaluation was performed by five speech therapists. An ordinal four-point interval scale was used to evaluate the degree of voice abnormality (Grade, G). Several statistical analyses were performed to test the validity and the diagnostic accuracy of the AVQI in the Finnish-speaking population.Results: The inter-rater reliability of four of the five raters was high enough to allow the use of Gmean in the validation. There was a statistically significant correlation between the AVQI scores and the evaluation of overall perceptual voice quality (r = 0.74).Conclusions: The results confirmed the good discriminatory power of the AVQI in differentiating between normal and abnormal voice qualities. The AVQI 02.02 threshold value for dysphonia was 2.87 in the Finnish-speaking population.