Objective: To investigate the validity and reliability of multiple listener judgments of hypernasality and audible nasal emission, in children with repaired cleft palate, using visual analog scaling (VAS) and equal-appearing interval (EAI) scaling.
Design: Prospective comparative study of multiple listener ratings of hypernasality and audible nasal emission.
Setting: Multisite institutional.
Participants: Five trained and experienced speech-language pathologist listeners from the Americleft Speech Project.
Measures: Average VAS and EAI ratings of hypernasality and audible nasal emission/turbulence for 12 video-recorded speech samples from the Americleft Speech Project. Intrarater and interrater reliability was computed, as well as linear and polynomial models of best fit.
Results: Intrarater and interrater reliability was acceptable for both rating methods; however, reliability was higher for VAS as compared to EAI ratings. When VAS ratings were plotted against EAI ratings, results revealed a stronger curvilinear relationship.
Conclusions: The results of this study provide additional evidence that alternate rating methods such as VAS may offer improved validity and reliability over EAI ratings of speech. VAS should be considered a viable method for rating hypernasality and nasal emission in speech in children with repaired cleft palate.
Keywords: Americleft; cleft palate; hypernasality; nasal emission; perceptual ratings; psychological scaling; reliability; speech outcome; validity.