The impact of stimulated vocal loudness on nasalance in dysarthria

This study was designed to determine the effect of stimulated vocal loudness on nasalance in individuals with various dysarthria subtypes. Thirty participants produced three stimulated levels of vocal loudness while reading a nonnasal passage. Data included dysarthria classification, vocal sound pressure level, nasalance, and listener perception of nasality. There was not a predictable relationship between a change in vocal sound pressure level (SPL) and a change in nasalance, nor did these changes result in consistent perceptual results. There were, however, dysarthria-specific effects of stimulated vocal loudness on nasality. Further, the study highlighted the importance of corroborating objective data with perceptual findings.