Susceptibility to and Release from Masking in Infancy and Childhood

描述（由申请人提供）：婴儿和儿童比成人更容易受到来自竞争背景声音的干扰。听觉掩蔽的这些发展效应对于听力正常的儿童来说可能是实质性的，但对于听力障碍的儿童来说更明显。尽管婴儿必须在竞争性声音的存在下学习言语和语言，但我们对影响儿童在噪音中听力的因素的了解有限，很少有研究涉及婴儿和听力障碍儿童所面临的具体挑战。该项目的长期目标是确定和解释在包含多个声源的复杂声学环境中听力发展的因素。拟议的实验将表征在存在竞争性背景声音的情况下听到目标音调或语音的能力的发展效果，并将确定声学提示组合，以改善听力正常和听力受损的婴儿和儿童在噪声中的听力。目的1将描绘从婴儿期到青春期的远程频率掩蔽的发展的时间过程。拟议中的研究将检验这一假设，即对远频背景声音干扰的敏感性随着年龄的增长而降低。目标2将调查在何种程度上，婴儿和儿童受益于提供强大的和/或冗余的听觉分组线索存在竞争的背景声音。这些研究将测试这一假设，即婴儿和儿童受益于声源隔离线索时，这些线索是相对稀疏的成年人少。目标3将确定在存在竞争性背景声音的情况下改善听力的声学线索，以帮助听力受损的婴儿和儿童。这项工作将测试的假设，听力障碍干扰的听觉处理能力有关的分离和选择的目标从背景声音。所有这三个目标的实验建议依赖于严格的行为方法，使用良好的特点多音调和噪声刺激，以及语音感知测试中存在的竞争噪声或语音掩蔽。拟议的研究结果将提供急需的规范性数据，并预计将有助于形成复杂的听觉感知的儿科措施。这些数据也有可能导致改进策略，以优化听力障碍婴儿和儿童的听觉信息传递。

DESCRIPTION (provided by applicant): Infants and children are more vulnerable to interference from competing backgrounds sounds than adults. These development effects in auditory masking can be substantial for children with normal hearing sensitivity, but are more pronounced for children with hearing impairment. Despite the fact that infants must learn about speech and language in the presence of competing sounds, we have a limited understanding of the factors that influence children's hearing in noise, and few studies have addressed the specific challenges faced by infants and children with hearing impairment. The long-term aim of this project is to identify and explain the factors responsible for the development of hearing in complex acoustic environments that contain multiple sources of sound. The proposed experiments will characterize developmental effects in the ability to hear target tones or speech in the presence of competing background sounds and will identify acoustic-cue combinations that improve hearing in noise for both normal-hearing and hearing-impaired infants and children. Aim 1 will delineate the time course of development for remote-frequency masking from infancy to adolescence. The proposed studies will test the hypothesis that susceptibility to interference from remote-frequency background sounds decreases with increasing age. Aim 2 will investigate the extent to which infants and children benefit from the provision of robust and/or redundant auditory grouping cues in the presence of competing background sounds. These studies will test the hypothesis that infants and children benefit less than adults from sound source segregation cues when those cues are relatively sparse. Aim 3 will identify acoustic cues that improve hearing in the presence of competing background sounds for infants and children with hearing impairment. This work will test the hypothesis that hearing impairment interferes with auditory processing abilities related to the segregation and selection of target from background sounds. Experiments proposed for all three aims rely on rigorous behavioral methods using well-characterized multi-tonal and noise stimuli as well as speech perception testing in the presence of competing noise or speech maskers. The results of the proposed studies will provide much needed normative data and are expected to contribute to the formation of pediatric measures of complex auditory perception. There is also the potential these data will lead to improved strategies to optimize the delivery of auditory information for infants and children with hearing impairment.