Diagnostics of the hearing organ by pulsed-DPOAE measurements of the ipsilateral olivocochlear reflex

本课题的目的是开发一种新的、高准确度和客观性的方法来诊断临床上的听力功能。为此，将使用所谓的失真产物耳声发射。耳声发射是耳蜗放大器的副产品，目前用于诊断依赖于外毛细胞的耳蜗放大器的状态。少数情况下，内毛细胞功能和通过脑干到达皮质的神经路径也会受到损害。众所周知，到达脑干的信号通过投射到内耳外毛细胞的传出纤维部分耦合回来，在那里它们略微改变了耳蜗放大器的操作点。这一效应将被用于诊断听力功能，包括直到脑干的神经功能。到目前为止，类似的方法失败的原因是：(1)传出信号引起的DPOAE变化很小，因此很难测量；(2)DPOAE容易受到其产生的两个源的干扰。使用一种新的脉冲方法来诱导DPOAE，我们的目标是实现对这种效应的更可靠的诊断。

The aim of this project is to develop a new, highly accurate and objective method for diagnosting the hearing function in the clinical practice. To this end, so-called distorsion-product otoacoustic emissions are to be used. Otoacoustic emissions are a by-product of the cochlear amplifier, and are currently used to diagnose the state of the cochlear amplifier which relies on the outer hair cells. Less frequently, inner-hair cell function and the neural paths to the cortex via the brainstem can also be impaired. It is known that signals arriving at the brainstem are partly coupled back via efferent fibers projecting to the outer hair cells in the inner ear, where they change the operating point of the cochlear amplifier slightly. This effect is to be used for diagnosing hearing function including neural function up to the brainstem. Up to now, comparable approaches failed due to the fact that (i) changes of DPOAE due to efferent signaling are of tiny size and therefore hard to measure, and that (ii) DPOAE are prone to interference of two sources of their generation. Using a new, pulsed method to elicit DPOAE, we aim to achieve a more reliable diagnosis of this effect.