Ear acoustic authentication is a new biometrics method and it utilizes the differences in acoustic characteristics of the ear canal between users. However, there have been few reports on the factors that cause differences in the acoustic characteristics. We investigate the relationship between ear canal shapes and acoustic characteristics in terms of user-to-user similarity. We used magnetic resonance imaging (MRI) to measure ear canal geometry. As a result, the correlation coefficient between shape similarity and acoustic characteristic similarity is higher than 0.7 and the coefficient of determination is higher than 0.5. This suggests that the difference in the shape of the ear canal is one of the important factors.

翻译：耳声学认证是一种新的生物测定方法,它利用了用户之间耳运河声学特性的差异,然而,关于造成声学特性差异的因素的报告很少。我们从用户与用户的相似性的角度调查耳声学形状和声学特性之间的关系。我们使用磁共振成像测量耳声学几何。结果,形状相似性和声学特征相似性之间的相关系数高于0.7,确定系数高于0.5。这表明耳声波形状的差异是重要因素之一。