Institute of Biology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria
J Exp Biol. 2020 Jul 30;223(Pt 14):jeb203224. doi: 10.1242/jeb.203224.
Sound localisation is a fundamental attribute of the way that animals perceive their external world. It enables them to locate mates or prey, determine the direction from which a predator is approaching and initiate adaptive behaviours. Evidence from different biological disciplines that has accumulated over the last two decades indicates how small insects with body sizes much smaller than the wavelength of the sound of interest achieve a localisation performance that is similar to that of mammals. This Review starts by describing the distinction between tympanal ears (as in grasshoppers, crickets, cicadas, moths or mantids) and flagellar ears (specifically antennae in mosquitoes and fruit flies). The challenges faced by insects when receiving directional cues differ depending on whether they have tympanal or flagellar years, because the latter respond to the particle velocity component (a vector quantity) of the sound field, whereas the former respond to the pressure component (a scalar quantity). Insects have evolved sophisticated biophysical solutions to meet these challenges, which provide binaural cues for directional hearing. The physiological challenge is to reliably encode these cues in the neuronal activity of the afferent auditory system, a non-trivial problem in particular for those insect systems composed of only few nerve cells which exhibit a considerable amount of intrinsic and extrinsic response variability. To provide an integrative view of directional hearing, I complement the description of these biophysical and physiological solutions by presenting findings on localisation in real-world situations, including evidence for localisation in the vertical plane.
声音定位是动物感知外部世界的基本属性。它使它们能够定位配偶或猎物，确定捕食者的接近方向，并启动适应性行为。过去二十年来自不同生物学科的证据表明，体型远小于感兴趣的声音波长的小昆虫如何实现类似于哺乳动物的定位性能。本综述首先描述了鼓膜耳（如蚱蜢、蟋蟀、蝉、蛾或螳螂）和鞭状耳（蚊子和果蝇的特定触角）之间的区别。昆虫在接收定向线索时面临的挑战因它们是否具有鼓膜耳或鞭状耳而有所不同，因为后者对声场的质点速度分量（向量量）做出响应，而前者对声场的压力分量（标量量）做出响应。昆虫已经进化出复杂的生物物理解决方案来应对这些挑战，这些解决方案为定向听觉提供了双耳线索。生理挑战是可靠地将这些线索编码到传入听觉系统的神经元活动中，对于那些由仅少数神经细胞组成的昆虫系统来说，这是一个特别棘手的问题，因为这些系统表现出相当大的内在和外在响应可变性。为了提供对定向听觉的综合观点，我通过介绍真实情况下的定位发现来补充对这些生物物理和生理解决方案的描述，包括在垂直平面上定位的证据。
