The physical model designed by Umeda and Teranishi simulating an arbitrary shape of the human vocal tract was a straight tube with a set of plastic plates inserted from one side. Although this model has the advantage that users can configure any shape of the vocal tract, manually manipulating several plates simultaneously is difficult. In this study, we present two models extending Umeda and Teranishi's work to overcome this disadvantage. The first model has a straight tube similar to the original Umeda and Teranishi's model, but the weight of the plates enables them to return to resting position automatically. The second model has a bent tube with the oral and pharyngeal cavities connected at 90 degrees. This feature simulates the actual human vocal tract. The plates move back to their original positions by means of spring coils. In both cases, the plates' automatic return movement facilitates manual manipulation as compared to the original Umeda and Teranishi's model.
Bibliographic reference. Arai, Takayuki (2015): "Two extensions of umeda and teranishi's physical models of the human vocal tract", In INTERSPEECH-2015, 2605-2606.