École d'orthophonie et d'audiologie, Université de Montréal, Montreal, Quebec, Canada.
PLoS One. 2010 Sep 24;5(9):e12975. doi: 10.1371/journal.pone.0012975.
Hearing ability is essential for normal speech development, however the precise mechanisms linking auditory input and the improvement of speaking ability remain poorly understood. Auditory feedback during speech production is believed to play a critical role by providing the nervous system with information about speech outcomes that is used to learn and subsequently fine-tune speech motor output. Surprisingly, few studies have directly investigated such auditory-motor learning in the speech production of typically developing children.
METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we manipulated auditory feedback during speech production in a group of 9-11-year old children, as well as in adults. Following a period of speech practice under conditions of altered auditory feedback, compensatory changes in speech production and perception were examined. Consistent with prior studies, the adults exhibited compensatory changes in both their speech motor output and their perceptual representations of speech sound categories. The children exhibited compensatory changes in the motor domain, with a change in speech output that was similar in magnitude to that of the adults, however the children showed no reliable compensatory effect on their perceptual representations.
The results indicate that 9-11-year-old children, whose speech motor and perceptual abilities are still not fully developed, are nonetheless capable of auditory-feedback-based sensorimotor adaptation, supporting a role for such learning processes in speech motor development. Auditory feedback may play a more limited role, however, in the fine-tuning of children's perceptual representations of speech sound categories.
听力能力对正常言语发展至关重要,然而,将听觉输入与言语能力提高联系起来的确切机制仍知之甚少。言语产生过程中的听觉反馈被认为通过提供有关言语结果的信息对神经系统起着关键作用,这些信息被用于学习和随后微调言语运动输出。令人惊讶的是,很少有研究直接调查典型发展儿童言语产生中的这种听觉-运动学习。
方法/主要发现:在本研究中,我们在一组 9-11 岁的儿童以及成年人中操纵了言语产生过程中的听觉反馈。在改变听觉反馈条件下进行一段时间的言语练习后,我们检查了言语产生和感知的补偿变化。与先前的研究一致,成年人在言语运动输出及其言语声音类别感知表示方面都表现出补偿性变化。儿童在运动领域表现出补偿性变化,言语输出的变化与成年人的变化幅度相似,但儿童在其言语声音类别感知表示方面没有可靠的补偿效应。
结果表明,9-11 岁的儿童,其言语运动和感知能力尚未完全发育,仍然能够进行基于听觉反馈的感觉运动适应,支持这种学习过程在言语运动发展中的作用。然而,听觉反馈在儿童言语声音类别感知表示的微调中可能发挥更有限的作用。