LAUSR

Real-time three-dimensional ultrasound offers new opportunities to investigate the spatial and temporal complexities of speech production, but ultrasound by itself continues to be limited in significant ways because (typically) only one surface of the vocal tract can be imaged: the tongue. Nevertheless, many of these limitations can be overcome by appropriately time-aligning and spatially registering ultrasound volumetric images with additional data streams, such as lateral webcam video, acoustic recordings, and digitized palate impressions. One method by which this may be accomplished makes use of a new open-source toolbox for MATLAB, called “WASL,” which was originally designed specifically for real-time three-dimensional ultrasound, but is now extensible to other biomedical imaging modalities, including MRI, CT, and two-dimensional ultrasound. Examples from a study of rhotic sound production illustrate how multimodal investigations of speech production featuring real-time three-dimensional ultrasound m...