Fibers of collagens, secret and unknown of the eardrum: role in the reception of sounds in frogs

The ear is a complex biomechanical system dedicated to sound perception, even though part of the auditory function is located in the central nervous system. The evolution of a tympanic ear has been a key innovation in solving the impedance problem between air and biological tissues allowing sound to reach the inner ear. The coupling between the two middle ear cavities has an effect on the directionality of the eardrum, which acts as a pressure difference sensor. We aim at identifying and quantifying in detail the tympanum structures related to sound perception. We will use nanotomography as a basis for the construction of a highresolution three-dimensional dataset. Such 3D models and comparisons between data obtained for 20 samples of species varying in their frequency response should enable the understanding of the biomechanical basis of hearing very high frequency sounds.

耳朵是一套专司声音感知的复杂生物力学系统，尽管听觉功能的一部分位于中枢神经系统中。鼓膜耳（tympanic ear）的演化是解决空气与生物组织间声阻抗匹配难题、使声音得以传至内耳的一项关键创新。两个中耳腔（middle ear cavities）之间的耦合作用会影响鼓膜的方向性，而鼓膜作为压差传感器发挥功能。本研究旨在详细识别并量化与声音感知相关的鼓膜结构。我们将以纳米计算机断层扫描（nanotomography）为基础，构建高分辨率三维数据集。此类三维模型结合针对20个具有不同频率响应特性的物种样本所获取的数据开展的对比分析，将助力我们揭示极高频听觉的生物力学基础。