Reliability and clinical relevance of perceptual evaluation of pathological voices.

The perceptual GIRBAS scale for deviant voice quality was tested in 5 different institutes on 943 voice patients. Each voice was evaluated separately by 2 professionals. The interrater and intrarater correlation is satisfactory for G, R and B. Experience with the scale significantly improves the interrater agreement. Further, GIRBAS/acoustical correlations were investigated by using the multidimensional voice program (MDVP) of Kay. Principal component analysis allows reduction of 21 MDVP parameters to 5 clinically relevant clusters, with a typical acoustical measurement for each of them. The GIRBAS scale seems to be a valuable instrument for clinical practice.