Vertebrate pressure-gradient receivers

摘要: The eardrums of all terrestrial vertebrates (tetrapods) are connected through Eustachian tubes or interaural canals. In some the animals, these connections create pressure-gradient directionality, an enhanced directionality by interaction sound arriving at both sides eardrum and strongly dependent on transmission attenuation. Even though tympanic middle ear has originated independently in major tetrapod groups, each group ancestral condition probably was that two ears were exposed mouth cavity with relatively high transmission. Recent form a continuum from perfect (0 dB certain frequency band) pronounced (30-40 dB) lizards, over somewhat attenuated limited birds frogs, to functionally isolated pressure receiver mammals. Since binaural already takes place animals coupled ears, producing time level differences, subsequent neural processing may be simpler. robotic simulations simple subtraction (EI cells, found brainstem nuclei frogs lizards) produces lateralized responses sufficient for steering animal robustly sources.