The Prosodic Marionette: a method to visualize speech prosody and assess perceptual and expressive prosodic abilities

Speech technology applications have emerged as a promising method for assessing speech-language abilities and at-home therapy, including prosody. Many applications assume that observed prosody errors are due to an underlying disorder; however, they may be instead due to atypical representations of prosody such as immature and developing speech motor control, or compensatory adaptations by those with congenital neuromotor disorders. The result is the same - vocal productions may not be a reliable measure of prosody knowledge. Therefore, in this study we examine the usability of a new technology application to express prosody knowledge without relying on vocalizations using the Prosodic Marionette (PM) graphical user interface for artificial resynthesis of speech prosody. We tested the ability of neurotypical participants to use the PM interface to control prosody through 2D movements of word-icon blocks vertically (fundamental frequency), horizontally (pause length), and by stretching (word duration) to correctly mark target prosodic contrasts. Nearly all participants used vertical movements to correctly mark fundamental frequency changes where appropriate (e.g., raised second word for pitch accent on second word). A smaller percentage of participants used the stretching feature to mark duration changes; when used, participants correctly lengthened the appropriate word (e.g., stretch the second item to accent the second word). Our results suggest the PM interface can be used reliably to correctly signal speech prosody, which validates future use of the interface to assess prosody in clinical and developmental populations with atypical speech motor control.