Human pronunciation is a physiological process accomplished by the joint participation of several systems and organs, firstly, the power system built mainly by the respiratory system to produce airflow and subglottal pressure; secondly, the vibration system, in which the pair of vocal folds in the closed phase under the action of the power source produce vibrations to produce the basic sound; then the modulation of sound by the resonance system nasal cavity, pharyngeal cavity, oral cavity, thoracic cavity and other resonance cavities (enhance the sound waves of certain frequencies The final sound is formed by the activity of the lip, tooth, tongue and palate organs. In the whole process of articulation, the central nervous system (especially the auditory feedback) plays a regulatory control role. In other words, the physiological process of articulation is controlled by the nervous system, which consists of the dynamic system, vibration system, resonance system and the phonation system. The human body itself is a sophisticated musical instrument, if compared to a wind instrument, such as a saxophone, the vocal cords are equivalent to the reeds, the cavity is equivalent to the pharyngeal cavity, nasal cavity and other resonant cavity, and the power comes from the mouth blowing out the airflow. So which of these aspects have problems, it may affect the three elements of the sound – tone, timbre, sound intensity.