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Voice assessment: rating scales, acoustic measures, stroboscopy and referral
Voice assessment combines trained listening (GRBAS), self-report (VHI), acoustic and aerodynamic measures and an examination of the folds by an ENT doctor — and no voice therapy starts before the folds have been examined.
Why it matters in the exam
Exam questions test whether you can read a measure: what a given GRBAS score means, whether 1% jitter is better than 2% (yes), whether a higher harmonics-to-noise ratio is better (yes), what the VHI measures (the impact of the voice on functioning as the patient sees it), and what stroboscopy does (light flashes timed close to the fundamental frequency, creating an apparent slow motion of the mucosal wave).
An important part is clinical judgement: hoarseness and cough lasting two months need ENT referral; even when a psychogenic disorder seems obvious, treatment starts only after a medical examination; a voluntary cough gives an impression of fold closure; and laryngeal palpation tells about tension in the extrinsic muscles. You may also be asked how to find optimal pitch, for example by the lower-quarter-of-range method or a yawn-sigh.
Key points
- GRBAS: five features, 0–3, the highest is the dominant one.
- VHI: self-report of the voice's impact on life.
- Low jitter and shimmer are good; high HNR is good.
- Stroboscopy shows the mucosal wave with timed flashes.
- Persistent hoarseness — ENT referral before any treatment.
Summary table
| Tool | What it measures | How to interpret |
|---|---|---|
| GRBAS | Perceptual rating: overall grade, roughness, breathiness, asthenia and strain, each 0–3 | The highest score shows the dominant feature, for example R3 = marked roughness |
| VHI | Self-report questionnaire on the impact of the voice on functioning | A higher score = a greater handicap as the patient sees it |
| Jitter and shimmer | Cycle-to-cycle instability in frequency (jitter) and amplitude (shimmer) | A lower value = a steadier voice |
| Harmonics-to-noise ratio (HNR) | How much of the voice is periodic tone versus noise | A higher value = better voice quality |
| Maximum phonation time (MPT) | How long a vowel can be held on one breath | A very short time suggests incomplete closure or weak breath support |
| Stroboscopy | Light flashes timed close to the fundamental frequency | Apparent slow motion of the mucosal wave; shows closure, symmetry and stiffness |
| Palpation and voluntary cough | Tension in the extrinsic muscles; an impression of fold closure | A high larynx that will not move sideways suggests muscle tension |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
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- What matters for the exam
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Sources
- ASHA Practice Portal, 2024 — Voice Disorders
- Patel et al., American Journal of Speech-Language Pathology, 2018 — Recommended protocols for instrumental assessment of voice (ASHA expert panel)
- Jacobson et al., American Journal of Speech-Language Pathology, 1997 — The Voice Handicap Index (VHI)
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.