School of Foreign Studies, Nanjing University of Science and Technology, Nanjing, Jiangsu, China.
Department of Linguistics, The Centre for Language Sciences (CLaS), Macquarie University, Sydney, NSW, Australia.
Ear Hear. 2021 Sep/Oct;42(5):1405-1411. doi: 10.1097/AUD.0000000000001036.
Children with cochlear implants (CIs) face challenges in acquiring tones, since CIs do not transmit pitch information effectively. It has been suggested that longer CI experience provides additional benefits for children implanted early, enabling them to achieve language abilities similar to that of normal-hearing (NH) children (Colletti 2009). Mandarin is a tonal language with four lexical tones and a neutral tone (T0), characterized by distinct pitch and durational patterns. It has been suggested that early implantation (i.e., before 2 years) greatly benefits the acquisition of Mandarin tones by children with CIs (Tang et al. 2019c). In this study, we extend those findings to investigate the effect of CI experience on the acquisition of Mandarin tones for children implanted early. We asked the extent to which they were able to produce distinct pitch and durational patterns of both lexical tones and T0 as a function of CI experience, and the extent to which their tonal productions were acoustically like that of NH children.
Forty-four NH 3-year olds and 28 children implanted with CIs between 1 and 2 years, aged 3 to 7, were recruited. The children with CIs were grouped according to the length of CI experience: 3 to 6 years, 2 to 3 years, and 1 to 2 years. Lexical tone and T0 productions were elicited using a picture-naming task. Tonal productions from the children with CIs were acoustically analyzed and compared with those from the NH children.
Children with 3 to 6 years of CI experience were able to produce distinct pitch and durational patterns for both lexical tones and T0, with NH-like acoustic realizations. Children with 2 to 3 years of CI experience were also able to produce the expected tonal patterns, although their productions were not yet NH-like. Those with only 1 to 2 years of CI experience, however, were not yet able to produce the distinct acoustic patterns for either lexical tones or T0.
These results provide acoustic evidence demonstrating that, when Mandarin-speaking children are implanted before the age of 2, only those with 3 to 6 years of experience were able to produce NH-like tones, including both lexical tone and T0. Children with shorter CI experience (less than 3 years) were unable to produce distinct acoustic patterns for the different tones. This suggests that at least 3 years of CI experience is still needed for early implanted children to acquire tonal distinctions similar to those of NH 3-year olds.
患有耳蜗植入物（CI）的儿童在获取音调方面面临挑战，因为 CI 无法有效地传输音高信息。有人提出，更长的 CI 体验为早期植入的儿童提供了额外的益处，使他们能够达到与正常听力（NH）儿童相似的语言能力（Colletti 2009）。普通话是一种具有四个声调的声调语言，还有一个中声调（T0），其特点是音高和持续时间模式明显不同。有人提出，早期植入（即，2 岁之前）极大地有利于患有 CI 的儿童对普通话声调的获取（Tang 等人，2019c）。在这项研究中，我们将这些发现扩展到研究 CI 体验对早期植入的儿童普通话声调获取的影响。我们询问了他们在多大程度上能够根据 CI 体验产生明显的音高和持续时间模式，无论是词汇声调还是 T0，以及他们的声调产生在多大程度上与 NH 儿童相似。
招募了 44 名 NH 3 岁儿童和 28 名 1 至 2 岁植入 CI 的儿童，年龄在 3 至 7 岁之间。根据 CI 体验的长短，将植入 CI 的儿童分为三组：3 至 6 年，2 至 3 年和 1 至 2 年。使用图片命名任务引出词汇和 T0 发音。对植入 CI 的儿童的声调发音进行声学分析，并与 NH 儿童的发音进行比较。
具有 3 至 6 年 CI 体验的儿童能够为词汇和 T0 产生明显的音高和持续时间模式，具有 NH 类似的声学表现。具有 2 至 3 年 CI 体验的儿童也能够产生预期的声调模式，尽管他们的发音尚未具有 NH 特征。而只有 1 至 2 年 CI 体验的儿童，还无法为词汇和 T0 中的任何一个产生明显的声学模式。
这些结果提供了声学证据，表明当讲普通话的儿童在 2 岁之前植入时，只有那些具有 3 至 6 年经验的儿童才能产生类似 NH 的音调，包括词汇声调以及 T0。CI 体验较短（不到 3 年）的儿童无法为不同的音调产生明显的声学模式。这表明，至少需要 3 年的 CI 体验，早期植入的儿童才能获得与 NH 3 岁儿童相似的声调差异。
