Audibility, Sensory Aids and Cognition as Factors in Children's Speech Perception

描述(申请人提供)：听力障碍儿童和听力正常儿童之间最大的区别之一是词汇习得的速度。通常，听力正常的发育儿童每天可以学习2个以上的新单词，到5岁时已经掌握了4000-5000个单词。这与听力严重受损的儿童形成了鲜明的对比，后者在5岁时的词汇量可能只有500个单词(Bloom，2000；Conrad，1979)。词汇习得中的这些缺陷将影响高级语言能力的发展，包括句法、分词和最终的阅读理解。理解和改善词汇量的不足不仅可以提高单词识别能力，还可以加快其他语言能力的获得，这些能力对于交际和学术成功至关重要。具体目标1将确定影响听力受损儿童词汇习得的感觉、感知和认知因素(50名年龄在6-7岁、接受人工耳蜗植入或数字助听器的儿童；50名正常听力年龄的伙伴将在所有指标上进行比较)。拟检验的假设(D1.1-D1.3)基于这样一种观点，即听障儿童的接受性词汇需要感觉、知觉和认知能力的有效操作和整合。听力受损的儿童在日常环境(背景噪音和从柔和到响亮的所有级别的语音)中感知语言的能力有助于儿童“无意中听到”语言，并通过新词学习(内隐学习)促进接受性词汇量的增加。在严苛的听力条件下，儿童对言语的感知能力越差，他/她在工作记忆中保持信息的难度就越大。记忆广度的缩短会影响外显词汇习得，并导致词汇习得延迟，以接受性词汇量衡量。具体目标2的假设(D2.1和D2.2)将通过获取纵向数据，检验言语感知的长期影响和发展认知技能对词汇量的影响，来解决接受早期识别和设备使用的儿童语言增长速度的变异性。这项研究将使用综合多学科方法来考察感知和认知机制之间的相互作用，以理解和提高听力障碍儿童的语言技能。

DESCRIPTION (provided by applicant): One of the most profound differences between hearing-impaired and normal-hearing children is the rate of vocabulary acquisition. Typically developing children with normal hearing can learn more than 2 new words per day and have a vocabulary of 4,000-5,000 words by age 5. This is in stark contrast to the child with significant hearing loss who may have a vocabulary as small as 500 words at age 5 (Bloom, 2000; Conrad, 1979). These deficits in vocabulary acquisition will impact development of higher level language abilities including syntax, word segmentation and ultimately reading comprehension. Understanding and ameliorating deficits in vocabulary size can not only lead to improved word recognition but can also accelerate the acquisition of other linguistic competencies that are essential for communicative and academic success. Specific Aim 1 will determine the sensory, perceptual, and cognitive factors that mediate vocabulary acquisition in hearing impaired (50 children age 6-7 years with cochlear implants or digital hearing aids;50 normal hearing age mates will be compared on all measures). Hypotheses to be tested (D1.1-D1.3) are based on the idea that receptive vocabulary in hearing-impaired children requires the efficient operation and integration of sensory, perceptual, and cognitive abilities. Hearing impaired children's ability to perceive speech in every day environments (background noise and at all levels of speech from soft to loud) facilitates the child's ability to "overhear" language and promotes increased receptive vocabulary size through novel word learning (implicit learning). The less proficient a child is in perceiving speech in demanding listening conditions the more difficulty he/she will exhibit retaining information in working memory. Shortened memory span will influence explicit verbal learning and contribute to delayed vocabulary acquisition as measured by receptive vocabulary size. Hypotheses (D2.1 & D2.2) for Specific Aim 2 will address the variability in rate of language growth in children that have received early identification and device use by obtaining longitudinal data examining the long-term effects of speech perception and developing cognitive skills on vocabulary size. This study will use an integrated multidisciplinary approach to examine the interaction between perceptual and cognitive mechanisms in understanding and improving the linguistic skills of hearing impaired children.