A two-dimensional lip model for Mandarin Chinese

A two-dimensional lip model with inner lip information is provided in this paper. The lip model can precisely describe all possible lip states, which generally include complete closure, half opening, and full opening. By changing the values of the lip model’s parameters, all kinds of lip contours with different shapes can be generated, and the lip contours can fit the real lip shape quite well. The lip geometrical features based on lip contour are extracted and used to define a basic linguistic term, lip rounding. This paper has shown that the width of the inner lip is as important as the width of the outer lip when defining lip rounding. In the Audio-Visual (AV) speech perception experiment of the McGurk Effect, samples are developed with the aid of the lip model. The first sample is to keep all lip information including the tongue and the teeth information, the second sample is to keep both outer and inner lip information, and the last sample is to keep the outer lip information only. The result proves that the inner lip provides the most visual information of speech in the McGurk Effect experiment. It is concluded that the inner lip information is indispensable in the lip model for linguistic study based on the above research.