Hearing in Bats

描述（由申请人提供）：该项目的长期目标是确定哺乳动物听觉能力变化的生态学和形态学相关性，并研究视觉在听觉进化中的作用。它继续我们的比较方法，探索蝙蝠的广泛的听觉能力。蝙蝠提供了一个发现回声定位的听觉专门化可能对哺乳动物基本听觉能力产生的任何影响的机会。拟议的项目是对普通吸血蝙蝠（Desmodus rotundus）的听力进行比较调查。吸血鬼是本半球热带地区的一种害虫，对人类尤其是牲畜的健康构成严重危害。它们会导致牲畜严重失血，因为它们往往会反复从同一个人身上取食;它们也是疾病的载体。了解蝙蝠如何利用声音来寻找和识别猎物可能有助于指导控制工作。蝙蝠是中等大小的蝙蝠，使用低强度的调频回声定位信号寻找猎物对一个混乱的基板。与大多数蝙蝠不同，它们严重依赖被动倾听来发现猎物。因此，他们可能处于更重的选择压力下，以获得良好的声音定位敏锐度，也许利用高度发达的回声定位机制来增强被动定位。它们也可能对低频声音有些敏感，包括猎物的呼吸声，如果这是真的，这表明它们具有多功能的中耳和耳蜗机制来编码声音。我们将使用行为测试方法来确定1）在整个听力范围内的绝对灵敏度，2）检测非常短暂的声音和声音中非常短暂的间隙的能力，因为回声定位脉冲通常非常短（<5 ms）并且由非常短暂的间隔隔开，3）被动声音定位敏锐度，4）使用耳间时间和强度差异线索来确定位置的能力，5）声音定位与视觉的关系，因为蝙蝠对视觉的依赖各不相同。此外，我们还将研究与生物相关的声音的可探测性，包括人类的呼吸声和吸血鬼幼崽的交流叫声。这些声音的频谱将与成人听力图的频率范围和最佳灵敏度进行比较（适当时获得生物声音的行为检测阈值）。这项研究的最终目标是进一步了解听觉系统中的神经处理，以获得对人类听觉的看法。此外，我们将深入了解不同生活方式中感官的相互作用如何影响感知适应的演变以及这些适应背后的神经基质。吸血蝙蝠是本半球热带地区人类及其牲畜的直接健康危害。他们也是严重疾病的携带者。这个项目将有助于了解吸血鬼如何检测，定位和识别他们的猎物，以更好地管理牲畜的安全。

DESCRIPTION (provided by applicant): The long-range goals of this project are to determine the ecological and morphological correlates of the variation in hearing abilities of mammals and to examine the role of vision in the evolution of hearing. It continues our comparative approach to explore the wide range of hearing abilities in bats. Bats present an opportunity to discover any effects that the auditory specialization for echolocation may have had on basic mammalian auditory abilities. The proposed project is a comparative survey of hearing in Common Vampire bats (Desmodus rotundus). Vampires are a pest in the tropics of this hemisphere and a serious health hazard to humans and especially to their livestock. They can cause severe blood loss in livestock because they tend to feed repeatedly from the same individual; they also are vectors for disease. Understanding how Vampires use sound to find and identify prey may help guide efforts at control. Vampires are medium-sized bats that use low-intensity FM echolocation signals to seek prey against a cluttered substrate. Unlike most bats, they depend heavily on passive listening to detect prey. They may thus be under heavier selective pressure for good sound localization acuity, perhaps taking advantage of the highly developed echolocation mechanisms to enhance passive localization. They may also be somewhat sensitive to low-frequency sounds, including the breathing sounds of their prey, which, if true, suggests a versatile middle ear and cochlear mechanism for encoding sound. We will use behavioral tests methods to determine 1) absolute sensitivity throughout the hearing range, 2) the ability to detect very brief sounds and very brief gaps in sound, since echolocation pulses are usually very short (<5 ms) and separated by very brief intervals, 3) passive sound-localization acuity, 4) the ability to use interaural time and intensity difference cues for locus, and 5) the relation of sound-localization to vision, since bats vary in their reliance on vision. In addition we will 6) examine the detectability of biologically relevant sounds, including human breathing sounds and communication calls of vampire pups. The spectra of these sounds will be compared to the frequency range and best sensitivity of the adult audiogram (with behavioral detection thresholds for biological sounds obtained as appropriate). The ultimate goal of this research is to further our understanding of neural processing in the auditory system to gain perspective on human hearing. In addition, we will gain insight into how the interaction of the senses in different lifestyles has influenced the evolution of perceptual adaptations and the neural substrates underlying those adaptations. Vampire bats are a direct health hazard for humans and their livestock in the tropical regions of this hemisphere. They are also carriers of serious disease. This project will help understand how vampires detect, locate, and identify their prey for better management of safety of livestock.