计算机辅助设计和有限元分析法在耳模声学特性研究中的应用

Application of computer aid design and finite element method on the acoustic characteristics in earmold

目的探讨采用计算机辅助设计和有限元声固耦合计算方法分析耳模中导声管声学特性的可能性。方法通过螺旋断层数字扫描仪(computed tomography,CT)扫描并获取志愿者耳部数据,建立外耳模型,再布尔计算出耳模及导声管模型。应用Ansys软件和Aurical真耳分析仪分别计算和实测,输入90 d B声压,记录频率500~8000 Hz耳模导声管出口处压力值。结果有限元计算与实际测试耳模声学特性结果趋势相同;在导声管影响下耳模的共振频率在4000 Hz左右,最大增益约为24 d B,模拟计算结果较实际测试结果高6.8 d B。结论有限元分析方法可有效应用于耳模声学特性的研究。

Objective The possibility of using the computer aid design and the finite element method of acoustic-structural coupled to analyze transaudient of the acoustic tube in earmold is discussed.Methods First,we collect the whole ear data of a volunteer by computed tomography （CT） and build the 3D outer ear model.Second we obtain the earmold and the acoustic tube by Boolean operation.Third,we calculate and measure the transaudient characteristic of the acoustic tube at the range from 500 Hz to 8000 Hz under 90 dB SPL pressure by Ansys software and Aurical real-ear test equipment separately,and then we record the sound pressure at the outlet of acoustic tube.Results The trend of the results from the finite element analysis and the real-ear test are similar.The maximum gain of sound pressure level of finite element analysis is approximately 24 dB in 4000 Hz,which is 6.8 dB higher than that of the real-ear test.Conclusions Finite element method is effective to analyze transaudient of the acoustic tube in earmold.