The Reliability and Validity of Speech-Language Pathologists' Estimations of Intelligibility in Dysarthria

This study examined the reliability and validity of speech-language pathologists' (SLP) estimations of speech intelligibility in dysarthria, including a visual analog scale (VAS) method and a percent estimation method commonly used in clinical settings. Speech samples from 20 speakers with dysarthria of varying etiologies were used to collect orthographic transcriptions from naive listeners n=70 and VAS ratings and percent estimations of intelligibility from SLPs n=21. Intra- and interrater reliability for the two SLP intelligibility measures were evaluated, and the relationship between these measures was assessed. Finally, linear regression was used to evaluate the relationship between the naive listeners' orthographic transcription scores and the two SLP intelligibility measures. The results indicated that the intrarater reliability for both SLP intelligibility measures was strong, and the interrater reliability between the SLP ratings was moderate to excellent. A moderate positive relationship between SLPs' VAS ratings and percent estimations was also observed. Finally, both SLPs' percent estimations and VAS ratings were predictive of naive listeners' orthographic transcription scores, with SLPs' percent estimations being the strongest predictor. In conclusion, the average SLP percent estimations and VAS ratings are valid and reliable intelligibility measures. However, the validity and reliability of these measures vary between SLPs.

Automated summary

This study examined the reliability and validity of speech-language pathologists' estimations of speech intelligibility in dysarthria. The results showed that these estimations had strong intra- and interrater reliability and a moderate positive relationship between different methods. The estimations were also predictive of listeners' scores. Overall, the study concluded that these estimations are valid and reliable, although there may be variability between pathologists.