外中耳传声对响度感知影响的数值研究

Numerical analysis of the influence of external and middle ear on loudness perception

现有响度模型主要通过滤波器组在传递特性上模拟人耳感声特性,未能真实反映人耳的生理结构。基于新鲜人体颞骨标本微CT扫描影像,通过逆向成型技术及有限元法建立了基于真实生理结构的人耳模型,并基于该模型,研究外、中耳与人耳响度感知的关系。该模型主要包括耳道和中耳两个部分,通过镫骨、鼓膜脐部位移响应,镫骨速度传递函数及鼓膜处声压级对模型进行可靠性验证。最终,基于该模型,系统分析了经过外、中耳传声,传递到镫骨的镫骨底板输出位移、速度、能量与响度感知听阀曲线的关系。研究结果表明,镫骨底板输出的等速曲线及等能量曲线在中、高频段内与听阀曲线较接近,可以用于近似评估人耳在该频段内的响度感知效果。

In the existing loudness model, the characteristics of the human ear are simulated by a filter set, but the physiological structure of human ear is not reflected. In this paper, based on the micro-CT scanning image of a fresh human temporal bone specimen, and by using reverse modeling technique and finite element method, a loudness mod- el with real physiological structure is built. Then the relationship between the external and middle ear and the loudness perception is studied. This model consists of ear canal and middle ear, its validity is verified by the displacement re- sponse of stapes footplate and TM umbo, the velocity transfer function of stapes footplate and the sound pressure level at the tympanic membrane. Finally, based on this model, the relationship between the auditory threshold and the out- put displacement, velocity, power transmitted to the stapes footplate via ear canal and middle ear is analyzed systemat- ically. The results show that the isovelocity and isopower curves of the stapes footplate output are close to the auditory threshold curve in the middle and high frequency band, which can be used to evaluate the loudness perception effect of the human ear in this frequency band approximately.