The Effect of Anchors and Training on the Reliability of Voice Quality Ratings for Different Types of Speech Stimuli

Abstract

The main objective of the present study was to investigate if the type of voice stimuli-sustained vowel, oral reading, and connected speech-results in good intrarater and interrater agreement/reliability. A short-term panel study was performed. Voice samples from 30 native European Portuguese speakers were used in the present study. The speech materials used were (1) the sustained vowel /a/, (2) oral reading of the European Portuguese version of "The Story of Arthur the Rat," and (3) connected speech. After an extensive training with textual and auditory anchors, the judges were asked to rate the severity of dysphonic voice stimuli using the phonation dimensions G, R, and B from the GRBAS scale. The voice samples were judged 6 months and 1 year after the training. Intrarater agreement and reliability were generally very good for all the phonation dimensions and voice stimuli. The highest interrater reliability was obtained using the oral reading stimulus, particularly for phonation dimensions grade (G) and breathiness (B). Roughness (R) was the voice quality that was the most difficult to evaluate, leading to interrater unreliability in all voice quality ratings. Extensive training using textual and auditory anchors and the use of anchors during the voice evaluations appear to be good methods for auditory-perceptual evaluation of dysphonic voices. The best results of interrater reliability were obtained when the oral reading stimulus was used. Breathiness appears to be a voice quality that is easier to evaluate than roughness.