An imaging system correlating lip shapes with tongue contact patterns for speech pathology research

Abstract

In this research, an imaging system was built to work with a newly developed electronic device to help people produce sounds correctly. The system consists of two parts, the internal tongue contact pattern data collection and the external lip shape information analysis. The tongue position information was gathered using the palatometer, an innovative tongue contact pattern-tracking device invented by Dr. Samuel Fletcher. The lip shape information was collected by processing images taken from people articulating different sounds. We developed an efficient color image segmentation technique to extract lip contour points and form a closed curve for shape analysis. The geometry invariant turn function vs. normalized length was then calculated for the lip shape for each sound and compared against the turn function of the lips in a resting position to quantify their variations from this reference. Both internal (vocal tract) and external (visible lip shape) information was collected for each of the speech sounds. The lip shape information extracted from the images was then correlated with tongue position information. The test results showed that this imaging system can be used to quantify the lip shape information and its relations with the tongue position and is a potentially useful tool for speech pathology research.