Cochlear Mechanisms of Otoacoustic Emission Generation

先天性和后天耳聋很可能成为未来十年或二十年澳大利亚劳动力、澳大利亚年轻人和某些类别的早产儿残疾的主要原因之一。虽然不会危及生命，但听力障碍剥夺了个人最基本的社会需求之一：与他人沟通的能力。虽然恢复失去的听力所能做的很少，但重要的是尽早发现听力损失，以减少进一步的损失（在接触噪音的成年人的情况下，通过行为改变），并为非常年幼的儿童提供听力援助，使他们能够在尽可能早的年龄接触某种程度的听觉体验。为此，耳声发射现象，即来自耳朵的噪音，现在已经被认识了二十年，很可能在下一个千年的最初几年变得更加重要。耳声发射首先被证明是非常柔和的回声在点击刺激后10毫秒左右的延迟后从耳朵中重新出现。这些回声是耳朵在正常工作时产生的声音，如果个人的听觉灵敏度低于正常水平，回声就会消失。人们已经发现了几种其他形式的耳声发射，并迅速应用于听力测试，因此今天评估新生儿和其他无法合作的人的听力状况的技术以及诊断应用已经广泛应用。然而，这项技术的应用在真正理解耳声发射是什么以及它们是如何产生的之前就已经开始了，目前它们的广泛应用有点类似于不了解发动机如何工作的汽车修理行业。本研究旨在探讨耳声发射的基本机制，以提高临床解释的效率和准确性。

Deafness, both congenital and acquired, is likely to be one of the major causes of disability in the Australian workforce, in young Australians, and in some categories of pre-term infants in the next decade or two. While not life-threatening, hearing impairment deprives individuals of one of their most basic social needs: the ability to communicate with others. Although little can be done to recover lost hearing, it is important to detect hearing loss as early as possible in order to reduce further loss (by behaviour modification in the case of noise-exposed adults) and to provide hearing assistance in very young children so that they may be exposed to some degree of auditory experience at as early an age as possible. To this end, the phenomenon of otoacoustic emissions, or noises from the ear, now recognised for twenty years, is likely to become even more significant in the early years of the next millennium. Otoacoustic emissions were first demonstrated as very soft echoes re-emerging from the ear after a delay of ten milliseconds or so following a click stimulus. These echoes are sounds produced by the ear as it goes about its normal function and are lost if the hearing sensitivity of the individual is below normal. Several other forms of otoacoustic emissions have been discovered and rapidly applied to the testing of hearing so that today the technique of assessing hearing status in neonates and others unable to co-operate, as well as in diagnostic applications, is widespread. The application of the technique, however, has preceded a real understanding of what otoacoustic emissions are and how they are generated, and their widespread use at the moment is somewhat akin to a car repair industry which does not understand how an engine works. This proposal intends to investigate the basic mechanisms behind otoacoustic emissions in order to improve their efficiency and accuracy of clinical interpretation.