15th International Congress of Phonetic Sciences (ICPhS-15)

Barcelona, Spain
August 3-9, 2003

Studying Articulatory Variability Using Functional Data Analysis

Laura L. Koenig (1), Jorge C. Lucero (2), Anders Löfqvist (1)

(1) Haskins Laboratories, USA
(2) University of Brasilia, Brazil

Production variability is frequently used as an index of the stability and maturity of the speech motor system. Here, we assess speech production variability using Functional Data Analysis (FDA). In FDA, a smooth warping function of time is used to align the data, and separate indices of temporal and amplitude variability are obtained. Results on adult kinematic data show that amplitude variability across articulators varies with place of constriction, suggesting task-specific production constraints. Amplitude and phasing indices for children and adults indicate both group differences (higher average indices in children relative to adults) and individual patterns of variability. Pilot data from a child treated for apraxia of speech show variability indices within normal limits. Overall, our work suggests that FDA may be useful for quantifying variability across populations and speaking tasks. This may have clinical utility in differentiating atypical speech production behavior, and/or in charting the success of treatment.

Full Paper

Bibliographic reference.  Koenig, Laura L. / Lucero, Jorge C. / Löfqvist, Anders (2003): "Studying articulatory variability using functional data analysis", In ICPhS-15, 269-272.