Sound Articulate Through Teeth And Throat

Since mediaeval times, velar and guttural and its opening closing mouth have had many transformations. This paper adopts historical comparison method. According to the characteristic of the sound, it deparates the developing process into three main times as medieval times, modern times(beginning, maturation,and develping) and nowadays. In every period chooses thyme diagrams that has representatively, through comparison and analysis, analogues sound for it; analyses its opening closing mouth, and obtains the form of this period.after the analysis had made before, compareds the conclusion, describes its transformations of initial and the opening closing mouth in the lengthways angle; and obtains the regular pattern of changes.