Description

The GRBAS Voice Assessment Scale is one of the most widely recognized and scientifically validated instruments for the perceptual evaluation of voice quality. Developed by Minoru Hirano (1981), it is internationally used by speech-language pathologists, otolaryngologists, phoniatricians, and voice specialists to assess the severity of voice disorders and monitor changes in vocal performance over time.

The scale is based on the clinician’s auditory-perceptual judgment of voice quality and evaluates five fundamental dimensions of vocal function, from which the acronym GRBAS is derived:

  • G (Grade): Overall severity of dysphonia or global voice abnormality.
  • R (Roughness): Perceived irregularity or harshness of the voice resulting from irregular vocal fold vibration.
  • B (Breathiness): Degree of audible air escape during phonation caused by incomplete glottal closure.
  • A (Asthenia): Weakness or lack of vocal power and intensity.
  • S (Strain): Perceived excessive vocal effort, tension, or hyperfunctional voice production.

The GRBAS scale is extensively used in both clinical practice and research, serving as a standard instrument for diagnosing voice disorders, monitoring treatment outcomes, and evaluating therapeutic interventions in individuals with dysphonia, organic and functional voice disorders, neurological conditions affecting phonation, and professional voice users.

Purpose

The primary purpose of the GRBAS Voice Assessment Scale is to provide a standardized perceptual evaluation of voice quality and to determine the severity of vocal disorders.

Additionally, the instrument is widely used to:

  • Diagnose voice disorders in clinical settings.
  • Assess voice quality before and after medical or therapeutic interventions.
  • Monitor progress during voice rehabilitation.
  • Evaluate professional voice users, including teachers, singers, actors, broadcasters, and public speakers.
  • Compare the effectiveness of different treatment approaches.
  • Support research in speech-language pathology, phoniatrics, otolaryngology, and voice science.

Data Analysis and Interpretation

Assessment with the GRBAS is performed through careful auditory evaluation by a trained clinician, either during live voice production or from recorded speech samples.

The evaluation process includes:

  • Perceptual listening to the voice.
  • Rating each of the five GRBAS dimensions (Grade, Roughness, Breathiness, Asthenia, and Strain).
  • Recording individual category scores.
  • Interpreting the overall vocal quality profile.

GRBAS scores are frequently examined alongside other objective and subjective voice assessment measures, including:

  • Acoustic voice analysis
  • Aerodynamic voice measurements
  • Laryngeal imaging and videostroboscopy findings
  • Voice-related quality of life measures
  • Patient-reported outcome measures such as the Voice Handicap Index (VHI)

Psychometric evaluation of the GRBAS commonly includes intra-rater and inter-rater reliability, calculation of the Intraclass Correlation Coefficient (ICC), and assessment of convergent validity through comparisons with acoustic, physiological, and patient-reported voice measures.

Scoring

Each of the five GRBAS dimensions is rated on a four-point ordinal scale:

  • 0 = Normal voice
  • 1 = Mild abnormality
  • 2 = Moderate abnormality
  • 3 = Severe abnormality

Each component is scored independently, producing a five-part profile (e.g., G2R1B0A0S2) that describes the perceptual characteristics of an individual’s voice. Repeated assessments enable clinicians to monitor rehabilitation progress, evaluate treatment effectiveness, and compare voice quality across different time points. When administered by trained evaluators using standardized procedures, the GRBAS demonstrates excellent clinical utility and satisfactory reliability, making it one of the international reference standards for the perceptual assessment of voice quality.

References

Hirano, M. (1981). Clinical Examination of Voice. Springer-Verlag.

Kreiman, J., & Gerratt, B. R. (2005). Perceptual Evaluation of Voice Quality. Journal of Voice, 19(1), 7–40.

Dejonckere, P. H., Remacle, M., Fresnel-Elbaz, E., Woisard, V., Crevier-Buchman, L., & Millet, B. (1996). Differentiated Perceptual Evaluation of Pathological Voice Quality: Reliability and Correlations with Acoustic Measurements. Revue de Laryngologie Otologie Rhinologie, 117(3), 219–224.

Karnell, M. P., & Melton, S. D. (2019). Clinical Voice Disorders (5th ed.). Thieme.