Liu, Y. 1 , Huang, Z. 1 & Chen, J. 2
1 Department of Athletic Performance, National Taiwan Normal University
2 Department of Chinese as a Second Language, National Taiwan Normal University
Motor control plays an important role in speech production. Using a reiterant speech paradigm, Kelso et al. (1985) proposed a dynamic model of speech production where the estimated stiffness value was identified as the tuning parameter for different gestures and prosodic conditions. The tones in Mandarin are the unique feature that helps identifying words and understanding meanings. The purpose of the study was to explore the relations between the stiffness values and the different gestures, tonal conditions in spoken Mandarin. Six university students and 2 pre-school children who were native speakers of Taiwanese Mandarin performed 16 reiterant speech tasks. Each task was made up of 4 or 5 sets of disyllabic words where all the syllables were replaced with /ba/. A 200 fps high speed camera and a digitizing system were used to capture the kinematics of the lips movements, and the amplitude and the peak velocity of the lip movements were derived to approximate the stiffness of the movement system while producing the rhythmic speech tasks. The results show that the average value of stiffness is higher for the open gestures than the close gestures, but the coefficient of variation of the stiffness value was greater for the close gesture. The children share the similar trend with a lower stiffness values in the open gestures. No consistent trend for different tonal conditions is observed. These results provide evidence to support the dynamic model of speech production.