Effect of level of presentation on scaled speech intelligibility of speakers with dysarthriafurther data.

Abstract

This study seeks to examine the effect of level of presentation on scaling of speech intelligibility of speakers with dysarthria. Previous data [Kim et al. (2007)] reported the somewhat surprising result that different presentation levels do not cause a significant change in speech intelligibility scores of speakers with dysarthria, but do for healthy speakers. The current study reports further data using the same speech stimuli, however, with a main focus on the across‐conditions effect of presentation level, since the previous data were limited to within‐conditions effects. Four conditions of level of presentation were generated by varying absolute level of presentation (high and low) and normalizing each utterance for peak vowel intensity (adjusted and nonadjusted). In this presentation, we will report how scaled speech intelligibility is affected by the level of presentation of speech samples produced by speakers with various types and severity of dysarthria and by healthy speakers. The results of this study will be helpful to understand the rationale of speech therapy for dysarthria, especially considering the frequent use of speech intelligibility and speech therapy techniques designed based on intensity variation of speech. [Work supported by NIH DC00319 and internal fund from Louisiana State University.]