Tongue‐Shaped Measurement Using Piezoelectric Thin Film
M. Matsumura, Katsuhiko Fujii · Systems and Computers in Japan · 1988
Abstract A tongue‐shaped measuring system was developed using a polymer piezoelectric film to analyze the tongue motion in harmonization of utterance. The copolymer piezoelectric film has a bimorph structure and produces a voltage proportional to the curvature of the tongue. By attaching the film on the tongue, the curvature at each point on the surface is measured, and the shape of the tongue is calculated from the curvature. To evaluate the shape measurement using the developed system, a simulator for the tongue shape was constructed, which has a curved surface of curvature between −0.4 to −0.57 cm−1. The shape of the simulator was measured. It was verified as a result that the error of estimation along the normal direction of the surface is within 0.5 mm, which is sufficient for the measurement of the tongue shape. Then the developed system was applied to measure the shape of the median and the frontal shape of the tongue during utterance. It is shown that the shape of the tongue during utterance can be measured. In the case of median shape, the curving. process from the main part to the tongue tip during the utterance of /r/ was clearly measured. The frontal shape, which has been difficult to measure, can easily be measured as in the case of the median shape, by modifying the placement of the copolymer piezoelectric film. The concave shape on the median line of the tongue during vowel harmonization was observed clearly.