Severity Cut-Off Ranges for Auditory-Perceptual Evaluation Using Visual Analog Scales

This retrospective, observational analytic, cross-sectional research study aimed to establish cut-off scores for categorizing the severity of voice qualities on a 100-unit visual analog scale (VAS). The study investigated the VAS cut-off ranges corresponding to auditory-perceptual ratings of normal, mild, moderate, and severe severities from the GRBAS scale for overall severity, breathiness, roughness, and strain.

The study utilized voice samples and ratings from the Perceptual Voice Qualities Database (PVQD). The database contains 296 audio samples, including sustained vowels and sentences, rated by 19 experienced voice clinicians. The raters used a 100-point VAS and the GRBAS scale to evaluate voice qualities. Receiver operator curves (ROC) were calculated to determine cut-off scores for each severity category, balancing a 90% sensitivity with a 10% allowable false-positive categorization.

Cut-off ranges were established for overall severity, breathiness, and roughness, demonstrating similar values across severities. The ranges were: Overall severity: normal (0-15), mild (16-39), moderate (40-69), severe (70-100). Breathiness: normal (0-14), mild (15-34), moderate (35-68), severe (69-100). Roughness: normal (0-13), mild (14-37), moderate (38-65), severe (66-100). For strain, only the normal range (0-15) could be determined with statistical significance.

This study provided clinically relevant cut-off values for severity categories on a VAS, enhancing communication with patients and facilitating the use of both sensitive and specific categorical measures in voice evaluation. The findings contribute to a more standardized and objective assessment of voice quality.