Selected acoustic characteristics of contrastive stress production in control geriatric, apraxic, and ataxic dysarthric speakers

Contrastive stress drills are often used in speech therapy to increase the intelligibility and communicative effectiveness of persons suffering from motor speech disorders. The rationale behind these drills is that the local effects of stress may improve articulatory performance on segments in the stressed word, as well as improve sentence-level prosodic adequacy. The purpose of the present investigation was to explore selected acoustic aspects of contrastive stress productions in control geriatrics and speakers with apraxia of speech and ataxic dysarthria. Results suggest that the phrase-level temporal and spectral effects of contrastive stress production among disordered speakers are not straightforward, and do not necessarily parallel those for normal speakers. These data are discussed relative to normal and disordered speech motor control.