Development and plasticity in normal and impaired ears

描述(由申请人提供)：该项目的长期目标是了解正常儿童和有渗出性中耳炎(OME)病史的儿童的听觉发育/可塑性。目标1和目标2分别涉及双耳时间处理和频谱处理的发展。目标3涉及有慢性OME病史的儿童言语知觉的发展和可塑性。目的1研究新发现的一种重要的双耳时间能力的发育方面，以利用在掩蔽噪声包络最小值中可获得的有利的信噪比。我们将检验两个具体的假设：1)儿童的这种能力显示出一种长期的改善，这可以通过双耳时间窗的发展来表征；2)这种能力可以解释到目前为止无法解释的成人和儿童掩蔽水平差异(MLD)的个体差异。第二个具体目标是研究解决和利用双耳耳间时间差(ITDS)中跨频差的能力。目标是开发有效的方法来表征这种能力及其发展，并检验这种能力在儿童中具有长期发展的假设。我们还将测试这一假设，即ITDS对跨频率差异的敏感性取决于伴随的刺激变量是否有利于综合或分析模式的处理。在目标3中，我们将使用语音感知方法来研究OME出现的异常/不稳定阈值和频谱形状条件下的听觉发育和可塑性。这些研究将检验这一假设，即在有OME病史的儿童中，频谱加权和组合来自不同频率区域的信息的能力是异常的，可能是因为在听觉发育过程中，语音信息的频谱形状在很长一段时间内是异常和不稳定的。心理声学研究将使用标准的自适应测试技术，语音研究将确定在安静或语音形状掩蔽噪声中出现的句子的正确率。该项目的所有阶段都将包括年龄匹配的对照听众。数据将使用方差分析和相关程序进行分析。

DESCRIPTION (provided by applicant): The long-term aim of this project is an understanding of auditory development/plasticity in normal children and in children having a history of otitis media with effusion (OME). Aims 1 and 2 concern the development of binaural temporal and spectral processing, respectively. Aim 3 concerns development and plasticity in the perception of speech for children who have histories of chronic OME. Aim 1 investigates developmental aspects of a newly identified important binaural temporal ability to take advantage of the favorable SIN ratios available in masking noise envelope minima. We will test two specific hypotheses: 1) this ability in children shows a protracted improvement that can be characterized in terms of the development of the binaural temporal window; 2) this ability can account for hitherto unexplained individual differences in the masking level difference (MLD) in adults and in children. The second specific aim investigates the ability to resolve and utilize across-frequency differences in binaural interaural time differences (ITDs). Goals are to develop efficient methods to characterize this ability and its development, and to test the hypothesis that this ability has a protracted development in children. We will also test the hypothesis that sensitivity to across-frequency differences in ITDs depends upon whether concomitant stimulus variables favor a synthetic or analytic mode of processing. In Aim 3 we will use a speech perception approach to investigate auditory development and plasticity under conditions of abnormal/unstable thresholds and spectral shape that occur with OME. These studies will test the hypothesis that spectral weighting and the ability to combine information from different frequency regions is abnormal in children with OME history, perhaps due to the fact that the spectral shape of speech information is abnormal and unstable for prolonged periods of time during auditory development. Psychoacoustic studies will use standard, adaptive testing techniques, and speech studies will determine percent correct for sentences presented either in quiet or in speech-shaped masking noise. All phases of the project will include age-matched control listeners. Data will be analyzed using analysis of variance and correlation procedures.