AVQI and ABI Explained: Why Multiparametric Analysis Outperforms Single Measures
🎯 Key Takeaways
- AVQI combines 6 parameters into one validated score for overall dysphonia severity
- ABI combines 9 parameters specifically targeting breathiness perception
- Clinical cutoffs: AVQI > 1.33 and ABI > 2.94 indicate dysphonia/breathiness (Brazilian Portuguese validation)
- Protocol: Counting 1-11 (continuous speech) + sustained /a/ vowel
- Calculate instantly with our free AVQI/ABI tool—the first web-based implementation
If you've ever felt frustrated trying to quantify voice quality with a single number, you're not alone. No single acoustic parameter—not jitter, not shimmer, not even CPP—captures the full complexity of how we perceive voice quality. That's where multiparametric indices come in.
The Acoustic Voice Quality Index (AVQI) and Acoustic Breathiness Index (ABI)represent a significant advancement in voice assessment. By combining multiple acoustic measurements into single, validated scores, they provide clinically meaningful numbers that actually correlate with what we hear perceptually.
In this guide, I'll explain what AVQI and ABI measure, why they work better than individual parameters, and how to implement them in your clinical practice—including access to the first free web-based calculator.
The Problem with Single-Parameter Assessment
Traditional acoustic analysis relies on individual measures like jitter, shimmer, HNR, or CPP. Each captures one aspect of voice quality:
- Jitter: Pitch stability (cycle-to-cycle F0 variation)
- Shimmer: Amplitude stability (cycle-to-cycle intensity variation)
- HNR: Signal clarity (harmonic vs. noise energy)
- CPP: Overall periodicity (cepstral peak prominence)
The challenge? Perceptual voice quality is multidimensional. A voice might have elevated jitter but normal shimmer—or vice versa. Which number do you report? Which correlates with patient outcomes?
The Clinical Dilemma
When individual parameters point in different directions, clinicians face a difficult question: which measure matters most? Multiparametric indices solve this by weighting and combining parameters based on their actual contribution to perceived voice quality.
What is AVQI?
The Acoustic Voice Quality Index (AVQI) was developed by Maryn et al. to provide a single, robust measure of overall dysphonia severity. It combines 6 acoustic parametersusing a regression formula derived from correlations with expert perceptual ratings.
AVQI's 6 Component Parameters
CPPS
Smoothed Cepstral Peak Prominence—overall periodicity measure
HNR
Harmonics-to-Noise Ratio—signal clarity
Shimmer Local
Cycle-to-cycle amplitude variation (%)
Shimmer (dB)
Amplitude perturbation in decibels
Slope
Spectral slope measure (LTAS)
Tilt
Long-term average spectrum tilt
A key innovation of AVQI is its use of combined speech samples: both continuous speech (counting numbers) and sustained vowel phonation. This captures voice quality across different phonatory contexts, improving ecological validity over sustained-vowel-only analysis.
Why Counting 1-11?
The protocol uses counting numbers because it provides standardized continuous speech across languages (numbers exist in all languages), minimizes linguistic complexity, and creates predictable phonatory patterns. For Brazilian Portuguese validation, counting 1-11 ("um" to "onze") provides approximately 3 seconds of voiced material.
What is ABI?
The Acoustic Breathiness Index (ABI) specifically targets the breathiness component of dysphonia. While AVQI measures overall voice quality, ABI isolates breathiness perception—critical for conditions like vocal fold paralysis, presbyphonia, or incomplete glottal closure.
ABI uses 9 acoustic parameters, with some overlap with AVQI but additional measures specifically sensitive to breathy voice characteristics:
ABI's 9 Component Parameters
CPPS
Periodicity measure
Jitter Local
Pitch perturbation
GNE Max
Glottal-to-noise excitation
HFNO
High-frequency noise offset
HNRD
HNR difference measure
H1-H2
First harmonic difference
Shimmer (dB)
Amplitude perturbation
Shimmer Local
Local amplitude variation
PSD
Power spectral density
Clinical Cutoff Values
Brazilian Portuguese Validation (Englert et al., 2021)
AVQI and ABI were validated for Brazilian Portuguese using 150 subjects. The validated cutoffs provide optimal sensitivity and specificity for dysphonia detection in this population.
| Index | Cutoff | Interpretation |
|---|---|---|
| AVQI | > 1.33 | Indicates presence of dysphonia |
| ABI | > 2.94 | Indicates perceptible breathiness |
Important: Higher scores indicate greater severity for both indices. A patient with AVQI of 3.5 has more severe overall dysphonia than one with AVQI of 2.0. Similarly, ABI of 4.5 indicates more prominent breathiness than ABI of 3.2.
Language-Specific Validation Matters
AVQI and ABI have been validated for multiple languages with different cutoff values. The cutoffs above (1.33 and 2.94) are validated for Brazilian Portuguese. If using with other languages, consult validation studies for that specific language, or use these values as general reference points while interpreting results cautiously.
Recording Protocol
Both AVQI and ABI require two recordings that are concatenated for analysis:
Continuous Speech
Patient counting numbers 1-11
- Normal conversational volume
- Steady, comfortable pace
- Quiet recording environment
- ~3-4 seconds duration
Sustained Vowel /a/
Patient sustaining "aahhh"
- 3-5 seconds duration
- Comfortable pitch and volume
- One continuous breath
- Don't fade at the end
AVQI vs ABI: When to Use Each
| Use Case | AVQI | ABI |
|---|---|---|
| General dysphonia screening | âś“ Primary | Supplementary |
| Vocal fold paralysis/paresis | âś“ Use | âś“ Primary |
| Presbyphonia (aging voice) | âś“ Use | âś“ Primary |
| Muscle tension dysphonia | âś“ Primary | Less relevant |
| Nodules/polyps | âś“ Primary | âś“ Useful |
| Treatment progress tracking | âś“ Essential | âś“ Essential |
Clinical Tip: Use Both Together
For comprehensive assessment, report both indices. A patient might show elevated AVQI (overall dysphonia) with normal ABI (not primarily breathy), suggesting the voice quality issue relates to roughness or strain rather than incomplete closure. This differential information guides treatment planning.
Common Questions
Q: Can I calculate AVQI/ABI with free software?
Yes! PhonaLab offers the first free web-based AVQI and ABI calculator. Simply upload your two recordings (counting + sustained vowel), and get instant results with all component parameters displayed. No installation required.
Q: How do AVQI and ABI relate to CPP?
CPP (specifically CPPS) is one component within both AVQI and ABI. Think of CPP as a single powerful measure, while AVQI/ABI are composite scores that include CPP alongside other parameters. AVQI/ABI provide a more complete picture by combining multiple perspectives on voice quality.
Q: Are smartphone recordings acceptable?
Yes, with proper protocols. Recent research supports smartphone recordings for AVQI/ABI when standardized methods are followed: quiet environment, consistent device positioning, high-quality recording settings. This makes these indices practical for telehealth applications.
Q: How often should I re-assess?
Track AVQI/ABI at regular intervals during treatment—typically every 4-8 sessions depending on treatment intensity. Changes of 0.5+ in AVQI or 0.8+ in ABI generally represent clinically meaningful improvement. Consistent measurement conditions (same recording setup) are essential for valid comparisons.
Bottom Line: Why AVQI and ABI Matter
- 1Multiparametric beats single-parameter—combining measures provides better correlation with perceived voice quality
- 2AVQI for overall dysphonia, ABI for breathiness—use both for comprehensive assessment
- 3Validated cutoffs: AVQI > 1.33, ABI > 2.94 (Brazilian Portuguese)
- 4Simple protocol: Counting 1-11 + sustained /a/ captures both connected speech and phonation
- 5Excellent for tracking progress—single numbers simplify documentation and patient communication
đź“Š Calculate AVQI & ABI Instantly
The first free web-based AVQI and ABI calculator. Upload your two recordings and get instant multiparametric analysis with all component parameters, clinical interpretation, and PDF reports.
Try Free AVQI/ABI Calculator →Validated for Brazilian Portuguese • Includes all 6 AVQI and 9 ABI component parameters
⚠️ Clinical Documentation Tool
The information in this article is provided for educational purposes and clinical documentation support. AVQI and ABI scores are intended to supplement—not replace—comprehensive voice evaluation including perceptual assessment, patient history, and laryngoscopic examination when indicated. Cutoff values represent statistical thresholds and should be interpreted within the full clinical context. All clinical decisions should be made by qualified healthcare professionals. PhonaLab tools do not provide medical diagnoses.
References & Further Reading
- Maryn Y, De Bodt M, Roy N. (2010). The Acoustic Voice Quality Index: Toward improved treatment outcomes assessment in voice disorders. Journal of Communication Disorders, 43(3), 161-174.
- Englert M, Latoszek BBV, Behlau M. (2021). Acoustic Voice Quality Index and Acoustic Breathiness Index for Brazilian Portuguese. Journal of Voice, 35(1), 152.e15-152.e22.
- Maryn Y, Corthals P, Van Cauwenberge P, Roy N, De Bodt M. (2010). Toward improved ecological validity in the acoustic measurement of overall voice quality: Combining continuous speech and sustained vowels. Journal of Voice, 24(5), 540-555.
- Barsties B, Maryn Y. (2015). The Acoustic Breathiness Index (ABI): A multivariate acoustic model for breathiness. Journal of Voice, 29(5), 552-558.
Dr. Jorge C. Lucero
Professor of Computer Science, University of BrasĂlia
Dr. Lucero has 30+ years researching voice production and vocal fold dynamics. PhonaLab's AVQI/ABI implementation has been validated against reference algorithms with less than 0.2% error, ensuring research-grade accuracy for clinical use.