The Usefulness of Auditory Perceptual Assessment and Acoustic Analysis for Classifying the Voice Severity

Acoustic Voice Quality Index (AVQI) in the Measurement of Voice Quality: A Systematic Review and Meta-Analysis

INTRODUCTION

Acoustic Voice Quality Index (AVQI) is a multiparametric construct of voice quality recognized for its clinical and research applications around the globe. This study aimed to review the validity and diagnostic accuracy of AVQI (v02&03) and determine the effects of age and gender.

METHODS

This is a systematic review and meta-analysis registered with the PROSPERO registry. The authors searched two databases (PubMed and Cochrane Library database) for relevant studies. Studies selected for the systematic review were grouped based on study objectives. To determine the quality of the selected studies, the authors utilized the QUADAS-2 tool.

RESULTS

Meta-analysis of seven studies on AVQIv02 revealed a diagnostic threshold ranging from 2.72 to 3.33 for AVQIv02. In comparison, eight studies investigating AVQIv03 suggested a diagnostic threshold ranging from 1.33 to 3.15 for AVQIv03. Altogether, these studies demonstrated a pooled sensitivity and specificity of 0.85 and 0.92 for AVQIv02 and 0.82 and 0.92 for AVQIv03. The Area under the Curve was slightly better for AVQIv03 (0.94) than AVQIv02 (0.92). Three studies investigating the effect of age and gender on AVQI had a consensus that AVQI is independent of gender. However, findings were contradictory about the impact of age on AVQI.

CONCLUSIONS

AVQI is found to be a valid tool for the assessment of voice quality. AVQIv03 is slightly better than AVQIv02 in its diagnostic accuracy. AVQI is independent of gender. Because of the contradictory evidence, additional research on the effects of age on AVQI is necessary.

Usefulness of Direct Magnitude Estimation (DME) and Acoustic Analysis in Measuring Dysphonia Severity

OBJECTIVES

The purposes of this study were (1) to analyze the reliability of direct magnitude estimation (DME) in auditory perceptual assessments measuring dysphonia severity and (2) to analyze the relationship between DME and four acoustic parameters (cepstral peak prominence [CPP], cepstral peak prominence-smoothed [CPPs], Acoustic Voice Quality Index [AVQI], and Acoustic Breathiness Index [ABI]) and (3) to predict dysphonia severity based on DME using four acoustic parameters.

STUDY DESIGN

One hundred and sixty-one voice samples for dysphonia patients were used. In this study, we combined sustained vowel samples and connected speech samples using the Praat software to make the concatenated samples for implementing acoustic analysis and auditory perceptual assessments. For acoustic analysis, we analyzed each value of CPP, CPPs, AVQI, and ABI. For auditory perceptual assessments, three speech-language pathologists evaluated dysphonia severity from the concatenated samples. Finally, we performed a stepwise multiple regression analysis to verify which combination of the four acoustic parameters could best predict perceived dysphonia severity based on the DME.

RESULTS

DME was found to have high reliability for auditory perceptual assessments measuring dysphonia severity, and there was a significant correlation between DME and four acoustic parameters. Finally, a two-variable model (AVQI and ABI) was useful for predicting perceived dysphonia severity based on the DME.

CONCLUSIONS

We verified the usefulness of DME scales in judging the dysphonia severity of dysphonic patients when used with acoustic analysis. Also, the two-variable model was useful to predict perceived dysphonia severity based on the DME.

Diagnostic Accuracy of DSI and AVQI v.02.03 in Discriminating across the Perceptual Levels of Dysphonia in Kannada Speaking Population

The present study investigated and compared the diagnostic accuracy of Dysphonia Severity Index (DSI) and Acoustic Voice Quality Index (AVQI) in Indian adults in the age range of 18-40years across different levels of dysphonia severity. Normophonic individuals (n=163) and individuals with dysphonia (n=134) were selected using purposive sampling in the age range of 18-40years. For DSI, Computerized Speech Lab 4500 and for AVQI, Praat 6.1.03 was used for recording. The results of receiver operating characteristics (ROC) analysis for DSI have revealed that DSI can discriminate the normophonic versus mild, mild versus moderate, and moderate versus severe dysphonic with cut-off values of 1.36, -1.83, and -4.07, respectively. The sensitivity and specificity reported for mild versus moderate and moderate versus severe are slightly lower for obtained threshold points. For AVQI v.02.03, ROC analysis revealed that high sensitivity and specificity cut-off points for normophonic versus mild, mild versus moderate, and moderate versus severe dysphonic are 2.50, 3.86, and 6.21, respectively. AVQI is a more effective technique than DSI for distinguishing between dysphonia severities levels, particularly when it comes to mild versus moderate and moderate versus severe, according to comparisons of AROC curves made using the DeLang method.

Auditory-perceptual Assessment of Healthy and Disordered Voices Using the Voice Deviation Scale

OBJECTIVE

This study aims to (1) determine the cut-off values of the Global Severity of vocal deviation on the Visual Analog Scale (VAS) from the numerical scale ratings, and (2) identify the cut-off values according to different degrees of vocal deviation used by Voice-Specialized Speech-Language Pathologists (SLP).

STUDY DESIGN

Prospective study.

METHODS

The auditory-perceptual assessment was performed by four SLPs using two protocols with different scales: the VAS and the 4-point numerical scale. Among the 211 voices analyzed, 147 corresponded to female participants, and 64 corresponded to males, plus 20% repeated voice samples. Participants were between 19 and 60 years. All of them were asked to count from 1 to 10 and were recorded in a sound-proof booth. For both protocols, the judges scored the overall severity. One SLP was excluded from the analysis due to inconsistency during the perceptual assessment.

RESULTS

For normal voice and mild deviations, overall severity cut-off score on the VAS was 21. For mild-moderate deviations, the cut-off was 55; and 81 points for moderate and severe deviations. The Area Under the Curve values correspond to 0.725, 0.905 and 0.851, respectively.

CONCLUSIONS

Our results suggest that the VAS is a good instrument to be used during voice assessment performed by Chilean SLPs. However, it evidences possible differences in voice analysis perception with other cut-off scores performed in other countries, which can be compared to future studies.

French-Language Adaptation of the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V)

OBJECTIVES

This study aimed to adapt the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) protocol for perceptual voice assessment to the French language. The primary objective was to achieve consensus among an international panel of voice experts on the content of the adapted protocol.

METHODS

To ensure the relevance and robustness of the French CAPE-V protocol, this study employed a systematic Delphi method and involved an international panel primarily comprising speech therapists and lecturers from France and Belgium. The multi-stage process included an initial panel size of 15 experts. Three rounds of online questionnaires, integrating both quantitative and qualitative data collection, were conducted. Participants provided feedback and ratings on various protocol elements until a consensus was reached. Adaptations targeted the choice of task stimuli (sustained vowel, sentence reading, semi-spontaneous speech), of the rating scales, and vocal quality terminology.

RESULTS

The Delphi process achieved consensus on all elements of the adapted CAPE-V protocol. Notably, the sustained vowel task saw consensus in favor of the vowel /a/. Sentence adaptations achieved substantial agreement, with the final set unanimously approved. The simple Visual Analog Scale emerged as the preferred rating scale. Agreement on terms for describing vocal qualities marked a crucial step in establishing a shared vocabulary among French-speaking voice experts.

CONCLUSIONS

The study successfully adapted the CAPE-V protocol for perceptual voice assessment to the French language through a systematic Delphi process. The final protocol closely resembles the original English version, maintaining its structure and core objectives. Consensus on sustained vowel tasks, sentence adaptations, rating scales, and vocal quality terminology indicates the relevance and robustness of the adapted protocol. Ongoing validation studies in France demonstrate the potential clinical utility of the adapted CAPE-V in French-speaking contexts, representing a significant step toward standardized and validated voice assessment tools for clinicians and researchers globally.

Risk of dysphonia and voice quality in performing arts students

PURPOSE

To analyse the relationship between the risk of dysphonia and vocal quality in undergraduate performing arts students.

METHODS

Observational cross-sectional study with 38 undergraduate students in Performing Arts. We applied screening protocols for general and specific risk of dysphonia for actors and made recordings of sustained emission of the vowel /a/, spontaneous speech and reading a text, used for perceptual analysis performed by three evaluators using the GRBASI scale. After intra and inter-rater reliability tests it was obtained final classification of the general degree of vocal deviation parameter for each participant. Comparisons were made considering groups that had or did not have other profession/activity with the use of voice, and the groups were formed from the general grade.

RESULTS

Most students were at high risk for dysphonia. All had vocal alteration, with a predominance of mild degree. Students who had another profession/activity with voice use scored higher in the specific protocol for actors, and in the sum of this protocol with the general screening protocol. There was no relationship between the degree of vocal alteration and the risk of dysphonia. Students who did not yet work professionally had more moderate or severe vocal alterations, and those who did work professionally had a higher frequency of mild vocal alterations.

CONCLUSION

Most students were at high risk for dysphonia. All had vocal alteration, with a predominance of mild alteration. There was no relationship between the risk of dysphonia and the degree of vocal alteration.

Normative Values of Cepstral Peak Prominence Measures in Typical Speakers by Sex, Speech Stimuli, and Software Type Across the Life Span

PURPOSE

The purpose of this study was to determine normative values for cepstral peak prominence measures across the life span as a function of sex using clinically relevant stimuli (/ɑ/, /i/, and two sentences of The Rainbow Passage) and two commonly used software types: Praat (Version 6.0.50) and Analysis of Dysphonia in Speech and Voice (ADSV).

METHOD

One hundred fifty speakers (75 males, 75 females; evenly distributed into three age groups) without voice disorders aged 18-91 years were recorded via headset microphone in a sound-treated booth. Cepstral measures were analyzed using common analysis methods in Praat and ADSV by sex, stimuli, and software type. Kruskal-Wallis tests and post hoc Mood's Median tests for significant factors were performed on cepstral measures to assess the effects of age group, sex, stimuli, and software type.

RESULTS

The results revealed statistically significant effects of sex, stimuli, and software type on cepstral measures, but no statistical effect of age group on cepstral values. Females had lower average cepstral values compared to males. Across stimuli, the highest average cepstral measure was found for sustained /ɑ/, followed by sustained /i/, and then of the two sentences of The Rainbow Passage. Average cepstral measures in Praat were higher than those from ADSV.

CONCLUSIONS

The current work did not find a statistical effect of age group on cepstral values; thus, normative cepstral values were reported by sex, stimuli, and software type. Future work should examine the applicability of these normative values for discriminating speakers with and without voice disorders.

Investigation of the Cepstral Spectral Acoustic Analysis for Classifying the Severity of Dysphonia

OBJECTIVES

The advantages of cepstral measurements in the evaluation of dysphonia have been noted in previous studies. However, there is an unclarity regarding the results of cepstral analyzes effect in determining the severity of dysphonia. The aims of this study were to determine the cut-off values of cepstral peak prominence, cepstral peak prominence standard deviation, low frequency/ high frequency ratio, low frequency/high frequency ratio standard deviation, and cepstral spectral index of dysphonia for predicting the voice severity within a Turkish speaking population, as well as to confirm the discriminative power of these cut-off values.

MATERIALS METHODS

One hundred ninety-five individuals with voice disorders and an equal number of age and gender-matched individuals without voice disorders were included. Included subjects had visited the Hacettepe University Hospitals Speech and Language Therapy Department for voice evaluation between January 2017 and September 2021. The voice recordings from all participants included the six CAPE-V/Turkish sentences and sustained vowel /a/. Three raters provided auditory perceptual ratings of the voice samples using the GRBAS scale (grade) and overall severity for the CAPE-V/Turkish. Participants were categorized into normal and mild, moderate, and severely dysphonic groups based on the auditory perceptual evaluation. Analysis of Dysphonia in Speech and Voice (ADSV) software was used for cepstral spectral acoustic analysis.

RESULTS

In the sustained vowel context, the area under the curve (ROC) for the CSID value was >0.8, except for mild vs. moderate dysphonia groups. In connected speech contexts, the ROC of the CPP value was also >0.8, except for normal vs. mild dysphonia groups. The cut-off values of CPP and CSID demonstrated high sensitivity and specificity for predicting voice severities.

CONCLUSION

The cut-off values for the parameters that predicted voice severities showed a significant degree of discriminative power for categorizing voice severities among Turkish-speaking people.

Reliability of Acoustic Measures in Dysphonic Patients With Glottic Insufficiency and Healthy Population: A COVID-19 Perspective

OBJECTIVES

The COVID-19 pandemic has affected the voice assessment protocols for dysphonic patients. In this study, we compared the changes in acoustic measures of the healthy population as well as dysphonic patients due to glottic insufficiency between the pandemic period requiring face masks and the prepandemic period when the masks were not essential. The clinical reliability of the acoustic measures with and without face masks was explored.

METHODS

A total of 120 patients (age = 42.3 ± 11.9 yrs) with glottic insufficiencies such as UVFP and sulcus vocalis and 40 healthy population (age = 40.5 ± 11.2 yrs) cohorts were enrolled during the pandemic period. Age- and gender-matched 120 patients and 40 healthy population cohorts who underwent voice assessment without face masks before the pandemic were enrolled as prepandemic controls. Acoustic measures and overall severity estimates of vowel and speech samples were compared, which included cepstral peak prominence (CPP), L/H spectral ratio (SR), their standard deviations, F0, jitter percent (Jitt), shimmer percent (Shim), noise-to-harmonic ratio (NHR), Cepstral Spectral Index of Dysphonia (CSID), and Acoustic Psychometric Severity Index of Dysphonia.

RESULTS

Both patients and healthy cohorts showed higher SRv and SRs but lower CSIDv during the pandemic compared to the prepandemic period. F0 of the healthy male controls during the pandemic was higher than during the prepandemic periods, while the CSIDs was lower for the pandemic period. The pandemic patient cohort showed lower σSRs compared to the prepandemic patient cohort. When the acoustic measures of patients were compared to the healthy population cohort, the patient cohort showed lower CPP and σCPPs, while higher σCPPv, Jitt, Shim, and NHR during both pandemic and prepandemic period. Overall, the area under the curve of the acoustic measures and overall severity estimates was similar between the mask and non-mask groups, although the AUC of the SR measures was poor.

CONCLUSIONS

Wearing face masks during the pandemic did not compromise the overall reliability of the acoustic analysis in patients with glottic insufficiency, suggesting the current protocol of acoustic analysis can be carried out reliably while wearing a mask to ensure safety in the pandemic era.

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

BACKGROUND

Acoustic measurements are useful tools to objectively measure overall voice quality. The Acoustic Voice Quality Index (AVQI) has shown to be a valid multiparametric tool to objectify dysphonia severity. The increasing number of validity studies investigating AVQI's validity demands a comprehensive synthesis of the available outcomes.

OBJECTIVE OF REVIEW

The aim of the present meta-analysis is to quantify the evidence for the diagnostic accuracy of the AVQI, including its sensitivity, specificity and likelihood ratio statistics, and its concurrent validity and sensitivity to changes in auditory-perceptual voice quality ratings.

TYPE OF REVIEW

Meta-analysis SEARCH STRATEGY: MEDLINE, EMBASE, the Cochrane library and Web of Science were searched from 2010 till April 2021 with an additional manual search, using keywords related to AVQI and common terminologies of validity outcomes. Studies considering the clinical validity of AVQI (ie, diagnostic accuracy, concurrent validity and sensitivity to change), using auditory-perceptual voice quality evaluation as reference, were included.

EVALUATION METHOD

The Preferred Reporting Items for Systematic reviews and Meta-Analyses of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines were used. Quality assessment of included studies was conducted using the QUADAS-2 tool. For the diagnostic accuracy of AVQI, the pooled sensitivity, specificity and likelihood ratio statistics were determined using a summary receiver operating characteristic approach. Weighted correlation coefficient measures (rW¯) were used to assess the concurrent validity and sensitivity to change.

RESULTS

A total of 198 studies were screened and 33 articles were included. In total, voice samples of 11447, 10272, and 367 different subjects were considered for analysis of diagnostic accuracy, concurrent validity and change responsiveness, respectively. Satisfying diagnostic accuracy results were found with a pooled sensitivity of 0.83 (95% CI: 0.82-0.83), a pooled specificity of 0.89 (95% CI: 0.88-0.90), a pooled positive LR of 7.75 (95% CI: 6.04-9.95), a pooled negative LR of 0.20 (95% CI: 0.16-0.23), and a pooled diagnostic odds ratio of 47.13 (95% CI: 34.82-63.79). Summary receiver operating characteristic curve analysis showed an excellent AUC value of 0.937 and Q* index of 0.874. Strong correlations of rW¯ = 0.838 for concurrent validity and rW¯ = 0.796 for sensitivity to change were found.

CONCLUSIONS

Our results confirm the general clinical utility of the AVQI as a robust and valid objective measure for evaluating overall dysphonia severity across languages and study methods.

"You Say Severe, I Say Mild": Toward an Empirical Classification of Dysarthria Severity

PURPOSE

The main purpose of this study was to create an empirical classification system for speech severity in patients with dysarthria secondary to amyotrophic lateral sclerosis (ALS) by exploring the reliability and validity of speech-language pathologists' (SLPs') ratings of dysarthric speech.

METHOD

Ten SLPs listened to speech samples from 52 speakers with ALS and 20 healthy control speakers. SLPs were asked to rate the speech severity of the speakers using five response options: normal, mild, moderate, severe, and profound. Four severity-surrogate measures were also calculated: SLPs transcribed the speech samples for the calculation of speech intelligibility and rated the effort it took to understand the speakers on a visual analog scale. In addition, speaking rate and intelligible speaking rate were calculated for each speaker. Intrarater and interrater reliability were calculated for each measure. We explored the validity of clinician-based severity ratings by comparing them to the severity-surrogate measures. Receiver operating characteristic (ROC) curves were conducted to create optimal cutoff points for defining dysarthria severity categories.

RESULTS

Intrarater and interrater reliability for the clinician-based severity ratings were excellent and were comparable to reliability for the severity-surrogate measures explored. Clinician severity ratings were strongly associated with all severity-surrogate measures, suggesting strong construct validity. We also provided a range of values for each severity-surrogate measure within each severity category based on the cutoff points obtained from the ROC analyses.

CONCLUSIONS

Clinician severity ratings of dysarthric speech are reliable and valid. We discuss the underlying challenges that arise when selecting a stratification measure and offer recommendations for a classification scheme when stratifying patients and research participants into speech severity categories.

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.

Cepstral Peak Prominence Values for Clinical Voice Evaluation

Purpose The goal of this study was to employ frequently used analysis methods and tasks to identify values for cepstral peak prominence (CPP) that can aid clinical voice evaluation. Experiment 1 identified CPP values to distinguish speakers with and without voice disorders. Experiment 2 was an initial attempt to estimate auditory-perceptual ratings of overall dysphonia severity using CPP values. Method CPP was computed using the Analysis of Dysphonia in Speech and Voice (ADSV) program and Praat. Experiment 1 included recordings from 295 patients with medically diagnosed voice disorders and 50 vocally healthy control speakers. Speakers produced sustained /a/ vowels and the English language Rainbow Passage. CPP cutoff values that best distinguished patient and control speakers were identified. Experiment 2 analyzed recordings from 32 English speakers with varying dysphonia severity and provided preliminary validation of the Experiment 1 cutoffs. Speakers sustained the /a/ vowel and read four sentences from the Consensus Auditory-Perceptual Evaluation of Voice protocol. Trained listeners provided auditory-perceptual ratings of overall dysphonia for the recordings, which were estimated using CPP values in a linear regression model whose performance was evaluated using the coefficient of determination (r ²). Results Experiment 1 identified CPP cutoff values of 11.46 dB (ADSV) and 14.45 dB (Praat) for the sustained /a/ vowels and 6.11 dB (ADSV) and 9.33 dB (Praat) for the Rainbow Passage. CPP values below those thresholds indicated the presence of a voice disorder with up to 94.5% accuracy. In Experiment 2, CPP values estimated ratings of overall dysphonia with r ² values up to .74. Conclusions The CPP cutoff values identified in Experiment 1 provide normative reference points for clinical voice evaluation based on sustained /a/ vowels and the Rainbow Passage. Experiment 2 provides an initial predictive framework that can be used to relate CPP values to the auditory perception of overall dysphonia severity based on sustained /a/ vowels and Consensus Auditory-Perceptual Evaluation of Voice sentences.

Monitoring the Outcome of Phonosurgery and Vocal Exercises with Established and New Diagnostic Tools

Instrument-assisted measuring procedures expand the options within phoniatric diagnostics by quantifying the condition of the voice. The aim of this study was to examine objective treatment-associated changes of the recently developed vocal extent measure (VEM) and the established dysphonia severity index (DSI) in relation to subjective tools, i.e., self-evaluation via voice handicap index (VHI-12) and external evaluation via auditory-perceptual assessment of hoarseness (H). The findings for H (3 raters' group assessment), VHI-12, DSI, and VEM in 152 patients of both sexes (age range 16–75 years), taken before and 3 months after phonosurgery or vocal exercises, were compared and correlated. Posttherapeutically, all of the recorded parameters improved (p < 0.001). The degree of H reduced on average by 0.5, the VHI-12 score sank by 5 points, while DSI and VEM rose by 1.5 and 19, respectively. The correlations of these changes were significant but showed gradual differences between H and VHI-12 (r = 0.3), H and DSI (r = −0.3), and H and VEM (r = −0.4). We conclude that all investigated parameters are adequate to verify therapeutic outcomes but represent different dimensions of the voice. However, changes in the degree of H as gold standard were best recognized with the new VEM.