STRUCTURE/FUNCTION RELATIONS IN MIDDLE EARS

描述：传导性听力损失由多种原因引起 病理性疾病，但所有这些都会降低人们的沟通能力。 现代外科实践包括戏剧性的手术治疗 传导性听力问题，包括重建异常或 病变的外耳和中耳，但一些治疗方法的效果 患者的听力往往是多变的，很难预测。在以下选项中选择 内科和外科治疗由诊断测试指导，由 医生的经验和病理如何影响正常的理论 外耳和中耳的突起。然而，目前的许多理论 是基于轶事证据，不完全经过测试的想法，或糟糕的 受控观察。动物的耳朵提供了一个机会 明确地确定结构变化对耳朵的影响 功能，并开发和测试耳朵的操作理论。这些 外耳和中耳的结构，控制收集和 将声音信号从环境传递到内耳，然后从那里 对大脑来说，它们的配置在不同物种之间以及在 从新生儿到成人的发育和可控的实验操作 在麻醉动物的生理实验中是可能的。我们用 所有这些方法来确定变异对听力的影响 外耳和中耳结构。 具体地说，中耳和外耳结构和功能的测量 将在具有不同中耳结构的麻醉啮齿动物身上制作 以及在猫的发育过程中。拟议的功能和结构措施 将引出外耳和中耳的量化理论 共同发挥作用。其中一个结果将是对如何 听力受到正常人气量变化较大的影响 和病态的人类中耳洞。这一知识的一个好处是 会不会是中耳液体的声学效应(异常 儿童中经常出现的情况)将被解释，并因此 两者都为医生对儿童听力损失原因的判断提供信息，并 使治疗效果的预测成为可能。我们的预期结果 也可能解释了人们识别方向的能力的缺陷 这种声音是由于耳朵结构不正常而发出的。听众的 在感知空间“本地化”说话者的能力对于 在不止一个人发言的环境中进行交流 同时，比如餐桌和汽车站。

DESCRIPTION: Conductive hearing losses result from a wide range of pathological conditions, but all degrade people's ability to communicate. Modern surgical practice includes dramatic procedures for treatment of conductive hearing problems, including reconstruction of abnormal or diseased external and middle ears, but the effects of some treatments on the patients hearing are often variable and hard to predict. Choices among medical and surgical treatments are guided by diagnostic tests, by physicians' experience and by theories of how pathologies affect the normal processes of the external and middle ear. However, many current theories are based on anecdotal evidence, incompletely tested ideas, or poorly controlled observations. The ears of animals provide an opportunity to determine unmistakably the effects of structural variations on the ear's function, and to develop and test theories of the ear's operation. These structures of the external and middle ear that control the collection and delivery of sound signals from the environment to the inner ear, and thence to the brain, vary in their configuration among species as well as during development from newborn to adult, and controlled experimental manipulation is possible in physiological experiments on anesthetized animals. We use all these approaches to determine the effects on hearing of variations of external- and middle-ear structures. Specifically, measurements of middle and external-ear structure and function will be made in anesthetized rodents with different middle-ear structures and in developing cats. The proposed functional and structural measurements will lead to a quantitative theory of how the external and middle ear function together. One result will be a quantitative understanding of how hearing is affected by the wide variations in the air volume of the normal and pathological human middle-ear cavities. One benefit of this knowledge will be that acoustic effects of fluid in the middle ear (an abnormal condition which occurs frequently in children) will be explained and thereby both inform physicians' judgments on causes of children's hearing loss and make possible prediction of the effects of treatments. Our expected results may also explain deficits in people's ability to identify the direction from which sound arrives, as a result of abnormal ear structures. A listener's ability to "localize" talkers, in perceptual space, is crucial to communication in environments where more than one person speaks simultaneously, such as dinner tables and bus stations.