Department of Neurosciences, KU Leuven-University of Leuven, Research Group Experimental ORL, Leuven, Belgium.
Department of Educational and Social Policy, University of Macedonia, Thessaloniki, Greece.
Ear Hear. 2020 Nov/Dec;41(6):1715-1731. doi: 10.1097/AUD.0000000000000893.
The present study investigated how children with cochlear implants (CIs), with optimal exposure to oral language, perform on sonority-related novel word learning tasks. By optimal oral language exposure, we refer to bilateral cochlear implantation below the age of 2 years. Sonority is the relative perceptual prominence/loudness of speech sounds of the same length, stress, and pitch. The present study is guided by a previous study that investigated the sonority-related novel word learning ability of a group of children with CIs, in the Greek language, of which the majority were implanted beyond the age of 2 unilaterally.
A case-control study with 15 Dutch-speaking participants in each of the three groups, i.e., children with CIs, normal-hearing children (NHC), and normal-hearing adults, was conducted using a sonority-related novel "CVC" word learning task. All children with CIs are implanted before the age of 2 years with preimplant hearing aids. Thirteen out of the 15 children had bilateral CIs. The CVC words were constructed according to four sonority conditions, where N is nonsonorous and S is a sonorous phoneme: NSN, NSS, SSN, and SSS. Outcome measures were accuracy and reaction times (RTs). In addition, the Peabody picture vocabulary test and the digit span forward test were administered to the children.
There were no statistical differences in accuracy or RTs between the children groups on the overall score and across the different conditions. However, children with CIs, unlike NHC, scored statistically less accurately and with longer RTs relative to normal-hearing adults, on the overall task. Within-group comparisons showed that none of the groups performed statistically differently on any of the conditions. The NHC showed higher receptive vocabulary scores relative to children with CIs. In addition, the group of children with CIs entailed a statistically significantly higher number of children with "weak" short-term memory.
Children with CIs who have optimal oral language exposure showed age-appropriate sonority-related novel word learning abilities and strategies relative to their NH peers. However, children with CIs continue to show lower receptive vocabulary scores than NHC, despite the equivalent novel word learning ability. This suggests that children with CIs may have difficulties in retaining newly learned words. Future work should look into possible causes of the gap in performance. This would eventually aid in rehabilitation tailored to the needs of the individual.
本研究旨在探讨在接受最佳口语语言输入的情况下，植入人工耳蜗的儿童在与音响度相关的新单词学习任务中的表现。通过最佳口语语言输入，我们指的是在 2 岁以下双侧植入人工耳蜗。音响度是指相同长度、重音和音高的语音的相对感知突出度/响度。本研究基于之前的一项研究，该研究调查了一组植入人工耳蜗的希腊语儿童在音响度相关的新单词学习能力，其中大多数儿童是在 2 岁以后单侧植入的。
采用病例对照研究，在三组中各有 15 名荷兰语参与者，即植入人工耳蜗的儿童、正常听力儿童（NHC）和正常听力成人，使用与音响度相关的新“CVC”单词学习任务进行。所有植入人工耳蜗的儿童均在 2 岁前使用植入前助听器。15 名儿童中有 13 名双侧植入人工耳蜗。CVC 单词是根据四个音响度条件构建的，其中 N 是非音响度，S 是音响度音素：NSN、NSS、SSN 和 SSS。结果测量为准确性和反应时间（RT）。此外，对儿童进行了 Peabody 图片词汇测试和数字跨度正向测试。
在总体得分和不同条件下，儿童组在准确性或 RT 方面没有统计学差异。然而，与正常听力成人相比，植入人工耳蜗的儿童在总体任务中的准确性得分较低，反应时间较长。组内比较显示，任何一组在任何条件下的表现均无统计学差异。NHC 的接受性词汇得分相对植入人工耳蜗的儿童更高。此外，植入人工耳蜗的儿童中，有统计学意义的是“较弱”短期记忆的儿童数量较多。
接受最佳口语语言输入的植入人工耳蜗的儿童表现出与正常听力同龄人相当的与音响度相关的新单词学习能力和策略。然而，尽管具有相同的新单词学习能力，植入人工耳蜗的儿童的接受性词汇得分仍然低于 NHC。这表明植入人工耳蜗的儿童可能难以记住新学的单词。未来的工作应该研究表现差异的可能原因。这最终将有助于为个体需求定制康复。
