Comparisons of 4-Point GRBAS, 7-Point-GRBAS, and CAPE-V for Auditory Perceptual Evaluation of Dysphonia

Abstract

Purpose: The GRBAS (grade, roughness, breathiness, asthenia, strain) scale, a 4-point scale, has been most widely used for judging auditory-perceptual severity for dysphonia. However, in current clinical practice, sometimes a more fragmented 0.5 scheme is being used if the original GRBAS scale is ambiguous to assess. Thus, the aim of the present study was to compare the dysphonia severity using the three auditory-perceptual evaluation tools, 4-point, 7-point GRBAS scale, and CAPEV and provide the information regarding differentiation of perceptual severity and acoustic correlations.Methods: Voice samples for sustained vowel and connected speech were obtained from 101 dysphonic patients. Auditory-perceptual assessments of dysphonia severity were performed by two certified experienced speech-language pathologists specializing in voice disorders using the grade of a 4-point and a 7-point GRBAS, OS of CAPE-V and also were compared with cepstral measures [cepstrum peak prominence (CPP), low/high spectral ratio].Results: OS and G of inter-rater reliability of dysphonia using CAPE-V and 4-point GRBAS scales were good (ICC > 0.800) while G of 7-point GRBAS was less strong (ICC > 0.681) than OS of CAPE-V and G of 4-point GRBAS scale. The highest correlation with CPP was the OS of CAPE-V in both vowel and connected speech, while L/H ratio showed low correlation with dysphonia severity. The OS of CAPE-V in vowel and connected speech differed significantly in G of both GRBAS scales. On the 4-point GRBAS scale, CPP showed only the difference between G1-G2, G2-G3 groups in /a/ vowel, whereas in the connected speech, the difference between G0-G1, G1-G2, and G2-G3 groups was relatively differentiated. Meanwhile, on a 7-point GRBAS scale, CPP showed only differences between G1.5-G2 groups in sustained vowel, while CPP showed no differences between G0-G0.5, G0.5-G1, G1-G1.5, G2-G2.5, and G2.5-G3 groups respectively in connected speech.Conclusion: 7-point GRBAS scale showed a higher correlation with CPP measures than the original GRBAS, but reduced the discrimination of dysphonia severity compared to the 4-point GRBAS scale. Consequently, modified 7-point GRBAS scale could be useful as a clinically-perceptual evaluation tool, along with the original GRBAS scale and CAPE-V.