Prosody and Discourse Marker
I conducted research on the speech prosody of children with Down Syndrome. Speech prosody, which involves both motor and cognitive mechanisms, is a crucial predictor of speech production in typical populations. Speech rhythm provides cues for segmenting linguistic information (syllables, words, phrases), and low-frequency information (e.g., stress syllable rates) is particularly important for speech intelligibility. Patterns of pitch accents, or emphases, signal new or important information and correlate with changes in F0, increased amplitude, and longer word duration. Typically, developing children produce stressed and unstressed syllables appropriate to the speech rhythm, accent new words in discourse, and interpret accents in real time from an early age.
However, compared with their mental-age-matched peers, children with Down syndrome (DS) exhibit prosodic impairments, including inappropriate stress and poorer prosodic imitation. Although they have speech production and linguistic delays, children with DS utilize some aspects of prosody, but their atypical F0 levels and variability impact their prosodic abilities. There is limited evidence that prosodic ability contributes to intelligibility in adults with DS or that speech prosody and speech accuracy are connected in children with DS. Therefore, examining prosody production as a predictor of both speech intelligibility and accuracy in children with DS is essential yet understudied. Disruptions in speech rates in children and adults with DS also warrant further investigation within prospective studies of speech intelligibility.