The Relationship of Selected Perceptual Measures of Diadochokinesis to Speech Intelligibility in Dysarthric Speakers With Amyotrophic Lateral Sclerosis

The current experiment explored the relationship of two perceptual measures of diadochokinetic (DDK) performance to speech intelligibility in 15 men with amyotrophic lateral sclerosis (ALS). The perceptual measures of DDK performance took the form of scalings of articulatory precision and rhythmic consistency. Regression analyses indicated that both measures were statistically significant in their ability to predict scaled speech intelligibility, although the efficiency of that prediction was somewhat better for articulatory precision than for rhythmic consistency. Regressions involving articulatory precision and rhythmic consistency were also found to be statistically significant. These results are discussed in terms of the clinical significance of DDK measures, especially their potential independence (or lack thereof) from general estimates of speech severity.