DEVELOPMENT AND PLASTICITY IN NORMAL AND IMPAIRED EARS

该项目的长期目标是了解正常儿童和特定临床儿童群体的听觉发育。 一个主要的研究领域是中耳炎对听觉发育的影响。 这一领域的具体目标是评估以下假设：有中耳炎病史的儿童在特定条件下对语音处理有特定损害：当双耳线索可用于掩蔽释放时，以及当任务设计为难以从掩蔽干扰中感知分离语音时。 第二个主要研究领域评估被诊断为特定语言障碍的儿童的听觉处理缺陷的性质。 一个具体的目标将是评估的假设，这样的听众有明确的赤字在编码的时间方面的信号。 竞争性假设将被评估，这些儿童在基于相对微妙/困难的线索的听觉处理中具有更普遍的缺陷。 一个相关的目的是控制听力损失史对特定语言障碍儿童的可能影响。 第三个主要研究领域将探讨双耳掩蔽释放的发展和基本机制。 对成年听众的基本实验将解决的问题，双耳掩蔽释放是否取决于选择性的时间加权的时间时期，有利于检测。 在这一领域的一项相关的发展研究将调查的发现，儿童减少了MLD的窄带噪声掩蔽，即使他们的MLD是成人一样的相对宽带掩蔽。 我们将研究的假设，儿童不利用窄带掩蔽谷时期包含最佳的信号噪声比。 在所有的研究领域中，大多数心理物理或语音识别方法将使用三选择或四选择强迫选择测试，并通过耳机进行声音呈现。 该项目的所有阶段都将包括年龄匹配的控制监听器。 将使用方差分析和相关程序分析数据。

The long-term aim of this project is an understanding of auditory development in normal children and in specific clinical popultions of children. One major Study Area is the effect of otitis media on auditory development. The specific aim in this area is assessment of the hypothesis that children with a history of otitis media have particular impairment for the processing of speech under particular conditions: when binaural cues are available for masking release, and when the task is designed such that it is difficult to perceptually segregate the speech from masking interference. The second major Study Area assesses the nature of auditory processing deficiencies in children diagnosed with specific language impairment. One specific aim will be to evaluate the hypothesis that such listeners have explicit deficits in coding the temporal aspect of the signal. The competing hypothesis will be assessed that such children have a more general deficit in auditory processing based upon relatively subtle/difficult cues. A related aim will be to control for possible effects of hearing loss history among the children with specific language disorder. The third major Study Area will investigate developmental and basic mechanisms of binaural masking release. Basic experiments on adult listeners will address the question of whether binaural masking release depends upon selective temporal weighting of temporal epochs that are favorable for detection. A related developmental study in this area will investigate the finding that children have reduced MLDs for narrowband noise maskers even though their MLDs are adult- like for relatively wideband maskers. We will examine the hypothesis that children do not take advantage of the narrowband masker valley epochs containing the best signal-to-noise ratios. In all Study Areas, most psychophysical or speech recognition methods will use three-alternative or four- alternative forced-choice testing with sound presentation over earphones. All phases of the project will include age-matched control listeners. Data will be analyzed using analysis of variance and correlation procedures.