Identification of Stress Placement in Speakers with and without Dysarthria

1. Identification of Stress Placement in Speakers with and without Dysarthria Pamela Campellone Thomas DiCicco Rupal Patel

2. Background • Traditional research focus in dysarthria due to CP: Articulation • More recent research: Prosody • Acoustic findings: Preserved prosodic control at vowel & word level

3. Background • Are acoustic signals consistent and reliable? • Can humans and/or machines make use of these signals? • If prosody is a strength, can it be harnessed to improve segmental clarity?

4. Research Questions • Can listeners identify stress within phrases produced by speakers with dysarthria & age-gender matched healthy controls? • How accurate is machine classification of prosodic contrasts?

5. Method • Spoken database: 12 speakers with dysarthria (DYS) & 12 healthy controls (HC) • 5 phrases (4 monosyllabic words) produced with stress on 1 of the 4 words or neutrally • 48 monolingual speakers of American English served as listeners • 4 listeners per DYS-HC speaker pair

6. Listener Interface

8. Acoustic Predictors of Listener Accuracy (p<0.01)

9. Machine Classification • HC & DYS words classified as stressed vs. unstressed • HC accuracy: 98.1% • DYS accuracy: 97.4% • Separate combinations of duration, intensity, & F0 used to determine which were most predictive

10. Accuracy by Acoustic Predictors

11. Conclusions • Unfamiliar listeners & machine classifier both highly accurate • Communicative potential of prosody • Clinically: scaffolding for improved intelligibility • Application: communication aids which utilize prosodic variation

12. Future Directions • Examine productions of speakers with varying etiologies of DYS • Differences in acquired vs. congenital? • Assess prosodic control in more varied speech tasks • Design comprehensive interventions incorporating speaker and listener variables