Acoustic and tongue kinematic vowel space in speakers with and without dysarthria

Purpose: The purpose is to investigate acoustic and tongue body kinematic vowel dispersion patterns and vowel space in speakers with and without dysarthria secondary to amyotrophic lateral sclerosis (ALS). Method: Acoustic and tongue kinematic vowel spaces were examined at the same time sampling point using electromagnetic articulography in 11 speakers with dysarthria secondary to ALS and 11 speakers without dysarthria. Tongue kinematic data were collected from the tongue body sensor (∼25 mm posterior from the tongue apex). A number of acoustic and tongue body kinematic variables were tested. Result: The result showed that the acoustic and tongue kinematic vowel dispersion patterns are different between the groups. Acoustic and tongue body kinematic vowel spaces are highly correlated; however, unlike acoustic vowel space, tongue body kinematic vowel space was not significantly different between the groups. Conclusion: Both acoustic and tongue kinematic vowel dispersion patterns are sensitive to the group difference, especially with high vowels. The tongue kinematic vowel space approach is too crude to differentiate the speakers with dysarthria secondary to ALS from speakers without dysarthria. To examine tongue range of motion in speakers with dysarthria, a more refined articulatory kinematic approach needs to be examined in the future.