Egolf D P, Kennedy W A, Larson V D
Audiology Research Program, V.A. Medical Center, Augusta, Georgia 30910.
J Acoust Soc Am. 1992 May;91(5):2813-23. doi: 10.1121/1.402962.
Ear simulators were designed to replicate acoustical characteristics of the average adult ear. Due to variability of ear-canal geometry and eardrum impedance among individuals, the possibility of any one person exhibiting such "average" characteristics--especially if that person is a child and/or has a conductive pathology--is remote. Thus, ear simulators have been of only peripheral value when prescribing a hearing aid (a high output impedance device) to fit the acoustical requirements of a particular patient. Reported herein is development of a programmable artificial ear (PAE) that can account for individual differences in ear-canal geometry and eardrum impedance. It consists of a 2.0-cc coupler, microphone, amplifier, computer, PAE code, and a computer card and/or software for digitization and Fourier transformation. Required input data includes ear-canal dimensions, eardrum impedance, and output impedance of the hearing aid being tested. Sound-pressure recordings produced in the 2.0-cc coupler by the hearing aid are adjusted by the computer to what they would have been had the recordings been made at the eardrum of a particular patient wearing the same hearing aid. Good agreement was observed between experiment and theory for one test case involving a totally occluding miniature earphone.
耳模拟器旨在复制普通成年人耳朵的声学特性。由于个体之间耳道几何形状和鼓膜阻抗存在差异，任何一个人呈现出这种“平均”特性的可能性很小，尤其是当这个人是儿童和/或患有传导性病变时。因此，在为特定患者配备助听器（一种高输出阻抗设备）以满足其声学要求时，耳模拟器的价值仅处于边缘地位。本文报道了一种可编程人工耳（PAE）的开发，它可以考虑到耳道几何形状和鼓膜阻抗的个体差异。它由一个2.0立方厘米的耦合器、麦克风、放大器、计算机、PAE代码以及用于数字化和傅里叶变换的计算机卡和/或软件组成。所需的输入数据包括耳道尺寸、鼓膜阻抗以及正在测试的助听器的输出阻抗。计算机将助听器在2.0立方厘米耦合器中产生的声压记录调整为如果在佩戴相同助听器的特定患者鼓膜处进行记录时的声压记录。在一个涉及完全封闭的微型耳机的测试案例中，实验与理论之间观察到了良好的一致性。
