Vertebrate pressure-gradient receivers
Vertebrate pressure-gradient receivers
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DOI：
10.1016/j.heares.2010.08.007
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发表时间：
2011-03-01
期刊：
影响因子：
2.8
通讯作者：
Christensen-Dalsgaard, Jakob
中科院分区：
文献类型：
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作者：
Christensen-Dalsgaard, Jakob
所有陆生脊椎动物（四足动物）的鼓膜都通过耳咽管或耳间管连接。在一些动物中，这些连接产生了压力梯度方向性，通过到达鼓膜两侧的声音的相互作用增强了方向性，并且强烈依赖于耳间传输衰减。尽管鼓室中耳在主要的四足动物中独立起源，在每一组中，祖先的条件可能是两个中耳暴露在口腔中，耳间传播相对较高。现代脊椎动物从完美的耳间传播形成连续体（在某一频段为0 dB）和明显的鼓膜方向性（30-40分贝）在蜥蜴，在有些衰减的传输和有限的方向性，在鸟类和青蛙，与哺乳动物中强烈衰减的耳间传输和功能隔离的压力接收耳有关。由于一些双耳相互作用已经在鼓膜处发生，在具有强耦合耳朵的动物中，产生增强的耳间时间和水平差异，随后的神经处理可能更简单。在蜥蜴的机器人模拟中，简单的双耳减法（在青蛙和蜥蜴的脑干核中发现的El细胞）产生强烈的侧化反应，足以将动物稳健地引导到声源。(C)2010 Elsevier B. V.保留所有权利。
The eardrums of all terrestrial vertebrates (tetrapods) are connected through Eustachian tubes or interaural canals. In some of the animals, these connections create pressure-gradient directionality, an enhanced directionality by interaction of sound arriving at both sides of the eardrum and strongly dependent on interaural transmission attenuation.Even though the tympanic middle ear has originated independently in the major tetrapod groups, in each group the ancestral condition probably was that the two middle ears were exposed in the mouth cavity with relatively high interaural transmission. Recent vertebrates form a continuum from perfect interaural transmission (0 dB in a certain frequency band) and pronounced eardrum directionality (30-40 dB) in the lizards, over somewhat attenuated transmission and limited directionality in birds and frogs, to the strongly attenuated interaural transmission and functionally isolated pressure receiver ears in the mammals.Since some of the binaural interaction already takes place at the eardrum in animals with strongly coupled ears, producing enhanced interaural time and level differences, the subsequent neural processing may be simpler. In robotic simulations of lizards, simple binaural subtraction (El cells, found in brainstem nuclei of both frogs and lizards) produces strongly lateralized responses that are sufficient for steering the animal robustly to sound sources. (C) 2010 Elsevier B.V. All rights reserved.