Ultrasound and acoustic analysis of lingual movement in teenagers with childhood apraxia of speech, control adults and typically developing children
Kocjancic, T. (2010) Ultrasound and acoustic analysis of lingual movement in teenagers with childhood apraxia of speech, control adults and typically developing children, no. 260.
Childhood apraxia of speech (CAS) is a neurological motor speech disorder affecting spatiotemporal planning of speech movements. Speech characteristics of CAS are still not well defined and the main aim of this thesis was to reveal them by analysing acoustic and articulatory data obtained by ultrasound imaging. Ultrasound recording provided temporal and articulatory measurement of duration of syllables and segments, amount and rate of tongue movement over the syllables and observation of the patterns of tongue movement. Data was provided by three teenagers with CAS and two control groups, one of ten typically developing children and the other of ten adults. Results showed that, as a group, speakers with CAS differed from the adults but not from the typically developing children in syllable duration and in rate of tongue movement. They did not differ from either of the control groups in amount of tongue movement. Individually, speakers with CAS showed similar or even greater consistency on these features than the control speakers but displayed different abilities to adapt them to changes in the syllable structure. While all three adapted syllable duration and rate of tongue movement in the adult-like way, only two showed mature adaptation of segment durations and of the amount of tongue movement. Observing patterns of tongue movement showed that speakers with CAS produce different patterns than speakers in the control groups but are at the same time, like adults, very stable in their articulations. Also, speakers with CAS may move their tongues less in the oral space than speakers in the control groups. The differences between the control groups were similar to those found in previous studies. The results provide support for the validity of the methods used, new information about CAS and a promising direction for future research in differential diagnostic and therapy procedures.