为分析中耳的声传递特性,采用声场与结构耦合的人耳有限元模型模拟声音在中耳中正向和逆向传递过程,分别获得外耳道声音激励经听骨链传递到耳蜗的中耳正向压力增益,以及耳蜗声音激励经中耳传递到外耳道的逆向压力增益.通过中耳正、逆向压力增益的乘积来分析声音在中耳往返传递的压力增益,评价中耳对耳声发射传递的影响.在1-3kHz范围内,计算结果显示中耳往返压力增益平均值为-18dB.
To evaluate the sound transfer across the middle ear in response to both normal acoustic stimulation and cochlear sound stimulation, an acoustic-structure coupled finite element model of human ear, consisting of the external ear canal, middle ear and cochlea, was used to analyze the trans- fer functions of human middle ear in the forward direction by an ear-canal sound source and in the re-verse direction by an inner ear sound source. The forward middle ear pressure gain and the reverse middle ear pressure gain were derived from the present model. The effect of the middle ear on otoa- coustic emissions (OAEs) was quantified by calculating the round trip middle ear gain as the product of the forward pressure gain and the reverse pressure gain. The results show that the mean round trip middle ear gain is about -18 dB in the 1-3 kHz region.