| Language is the most basic way of people communication. As people’s living standard improves and social interaction becomes more frequent, verbal exchange serves a very important part in people’s life, study and work and it is through speech’s way to get mutual everything for people. The basic condition of the language communication is voice for people and if voice quality of each person is different, expression languages will be different. As well as, People’s requirement is higher increasing on voice quality and ability of verbal exchange.Because voice prevalence continues to increase, voice disease not only affects people’s daily lives and the quality of work, but only will endanger the lives of patients. Therefore, diagnosis and inspection of voice disorders is very pivotal. Accurate inspection is the condition to cure voice disorders. Change of variety of benign and malignant proliferation for vocal will make the vocal elasticity, quality and tightness damage to varying degrees, and will lead to irregular vibration of the vocal cords, and bad opening and closing of glottal, which lead to voice disorders. With the rapid development of voice medicine science, in particular in order to improve excellent postoperative recovery of the voice, research and treatment of Voice are also played more attention.Aiming at sound pressure of far field generated by the vocal cord vibration in the space, elliptic model simulating actual vibration of vocal cord is applied according to the physiological structure and vibration characteristics of the vocal cord and acoustic knowledge. To simplify the calculation, assuming vocal model is composed of multiple point sources, and each point source is distributed on the ellipse equiangularly, the combination of point source is used to calculate far sound field directivity generated by the normal vocal cord vibration. The following aspects are carried out in this paper:1、The physical characteristics of the sound, the composition of the Vocal organs,vibration mechanism of vocal organs, factors affecting vocal cords and the basic theoretical knowledge of voice disease are introduced and discussed.2、Elliptic model simulating actual vibration of vocal cord is applied according to the physiological structure and vibration characteristics of the vocal cord and the basic theory of acoustic knowledge. Assuming vocal model is composed of multiple point sources, and each point source is distributed on the ellipse equiangularly, function of sound field directivity generated by the vibration model in the space is calculated, and then the acoustic field characteristics of vocal fold vibration model is discussed.3、Based on the physical model proposed, the directivity of sound field of normal vocal and lesion vocal cord model in space and any model plane (xoz) were calculated, and then get the formula, and acoustic pressure is made simulation analysis draw by MATLAB obtaining(1)Pressure is generated in the far sound field by model of vocal fold vibration and sound pressure amplitude generated by the model of vocal cords is related to the model number of sources n, that is to say, the value of n in that model will affect sound pressure amplitude of the far sound field produced by the vibration of the vocal cords.(2)Sound pressure variation is generated by the model of vocal fold vibration in xoz plane, as well as the frequency size and the opening size of the normal and diseased vocal directly affects the radiation acoustic pressure. And then that radiation acoustic pressure and relationship between the frequency and opening size of the vocal cord vibration model is learned.Through discussion and study of this article, it has an extremely important reference value for explanation and revelation of the basic characteristics of the human voice and pathological physiological characteristics of the voice, and it provides a theoretical reference for identifying the normal voice, disease diagnosis of voice and treatment program of voice disorders. |
PDF Full Text Request