Houston Derek M, Pisoni David B, Kirk Karen Iler, Ying Elizabeth A, Miyamoto Richard T
Department of Otolaryngology, Head and Neck Surgery, Indiana University School of Medicine, 699 West Drive, Indianapolis 46202, USA.
Int J Pediatr Otorhinolaryngol. 2003 May;67(5):479-95. doi: 10.1016/s0165-5876(03)00005-3.
We adapted a behavioral procedure that has been used extensively with normal-hearing (NH) infants, the visual habituation (VH) procedure, to assess deaf infants' discrimination and attention to speech.
Twenty-four NH 6-month-olds, 24 NH 9-month-olds, and 16 deaf infants at various ages before and following cochlear implantation (CI) were tested in a sound booth on their caregiver's lap in front of a TV monitor. During the habituation phase, each infant was presented with a repeating speech sound (e.g. 'hop hop hop') paired with a visual display of a checkerboard pattern on half of the trials ('sound trials') and only the visual display on the other half ('silent trials'). When the infant's looking time decreased and reached a habituation criterion, a test phase began. This consisted of two trials: an 'old trial' that was identical to the 'sound trials' and a 'novel trial' that consisted of a different repeating speech sound (e.g. 'ahhh') paired with the same checkerboard pattern.
During the habituation phase, NH infants looked significantly longer during the sound trials than during the silent trials. However, deaf infants who had received cochlear implants (CIs) displayed a much weaker preference for the sound trials. On the other hand, both NH infants and deaf infants with CIs attended significantly longer to the visual display during the novel trial than during the old trial, suggesting that they were able to discriminate the speech patterns. Before receiving CIs, deaf infants did not show any preferences.
Taken together, the findings suggest that deaf infants who receive CIs are able to detect and discriminate some speech patterns. However, their overall attention to speech sounds may be less than NH infants'. Attention to speech may impact other aspects of speech perception and spoken language development, such as segmenting words from fluent speech and learning novel words. Implications of the effects of early auditory deprivation and age at CI on speech perception and language development are discussed.
我们采用了一种已在听力正常（NH）婴儿中广泛使用的行为程序，即视觉习惯化（VH）程序，来评估聋儿对言语的辨别和注意力。
24名6个月大的听力正常婴儿、24名9个月大的听力正常婴儿以及16名在人工耳蜗植入（CI）前后不同年龄段的聋儿，在隔音室里坐在其照料者腿上，面对电视监视器接受测试。在习惯化阶段，每次向每名婴儿呈现一个重复的语音（如“hop hop hop”），在一半的试验中（“声音试验”）与棋盘格图案的视觉展示配对，在另一半试验中（“无声试验”）仅展示视觉画面。当婴儿的注视时间减少并达到习惯化标准时，测试阶段开始。测试阶段包括两次试验：一次“旧试验”，与“声音试验”相同；一次“新试验”，由不同的重复语音（如“ahhh”）与相同的棋盘格图案配对组成。
在习惯化阶段，听力正常的婴儿在声音试验中的注视时间显著长于无声试验。然而，接受了人工耳蜗植入的聋儿对声音试验的偏好要弱得多。另一方面，听力正常的婴儿和接受了人工耳蜗植入的聋儿在新试验中对视觉展示的注视时间都显著长于旧试验，这表明他们能够辨别语音模式。在接受人工耳蜗植入之前，聋儿没有表现出任何偏好。
综合来看，研究结果表明接受人工耳蜗植入的聋儿能够检测和辨别一些语音模式。然而，他们对语音的总体注意力可能低于听力正常的婴儿。对语音的注意力可能会影响语音感知和口语发展的其他方面，比如从流畅的言语中分割单词以及学习新单词。文中讨论了早期听觉剥夺和人工耳蜗植入年龄对语音感知和语言发展的影响。
