Temporally Resolved Articulatory Configuration Tracking of UltraSound (TRACTUS; Carignan, 2014) is a suite of Matlab (Mathworks, 2014) functions designed to perform temporal articulatory analysis on ultrasound images without the need for tracing of tongue contours. This software suite is freely available for download, distribution, and research use.
TRACTUS uses principal component analysis (PCA) to generate PC scores for each ultrasound frame and maps PC loadings onto their original spatial orientation (PC heatmaps). The PC scores for each ultrasound frame can be plotted sequentially and analyzed as temporal vectors which determine the extent to which each ultrasound frame is correlated with the given PC and associated heatmap. The PC scores can also be used as dimensions in discriminant or regression models to create articulatory signals which correlate with acoustic characteristics (example shown above) or articulatory configurations (example shown below).
Carignan, C. (2014). TRACTUS (Temporally Resolved Articulatory Configuration Tracking of UltraSound) software suite. URL: http://christophercarignan.github.io/TRACTUS. DOI: 10.13140/RG.2.2.27085.03047
Mathworks (2014). MATLAB R2014a (Version 8.3). URL: http://www.mathworks.com/products/matlab.