Language Sciences and Metrology Unit, University of Mons, Belgium.
Research Institute for Language Science and Technology, University of Mons, Belgium.
J Speech Lang Hear Res. 2024 Apr 8;67(4):1243-1267. doi: 10.1044/2024_JSLHR-23-00274. Epub 2024 Mar 8.
The present study investigates the perception of vowel nasality in French-speaking children with cochlear implants (CIs; CI group) and children with typical hearing (TH; TH group) aged 4-12 years. By investigating the vocalic nasality feature in French, the study aims to document more broadly the effects of the acoustic limitations of CI in processing segments characterized by acoustic cues that require optimal spectral resolution. The impact of various factors related to children's characteristics, such as chronological/auditory age, age of implantation, and exposure to cued speech, has been studied on performance, and the acoustic characteristics of the stimuli in perceptual tasks have also been investigated.
Identification and discrimination tasks involving French nasal and oral vowels were administered to two groups of children: 13 children with CIs (CI group) and 25 children with TH (TH group) divided into three age groups (4-6 years, 7-9 years, and 10-12 years). French nasal vowels were paired with their oral phonological counterpart (phonological pairing) as well as to the closest oral vowel in terms of phonetic proximity (phonetic pairing). Post hoc acoustic analyses of the stimuli were linked to the performance in perception.
The results indicate an effect of the auditory status on the performance in the two tasks, with the CI group performing at a lower level than the TH group. However, the scores of the children in the CI group are well above chance level, exceeding 80%. The most common errors in identification were substitutions between nasal vowels and phonetically close oral vowels as well as confusions between the phoneme /u/ and other oral vowels. Phonetic pairs showed lower discrimination performance in the CI group with great variability in the results. Age effects were observed only in TH children for nasal vowel identification, whereas in children with CIs, a positive impact of cued speech practice and early implantation was found. Differential links between performance and acoustic characteristics were found within our groups, suggesting that in children with CIs, selective use of certain acoustic features, presumed to be better transmitted by the implant, leads to better perceptual performance.
The study's results reveal specific challenges in children with CIs when processing segments characterized by fine spectral resolution cues. However, the CI children in our study appear to effectively compensate for these difficulties by utilizing various acoustic cues assumed to be well transmitted by the implant, such as cues related to the temporal resolution of stimuli.
本研究调查了植入人工耳蜗（CI 组）的法语儿童和听力正常的儿童（TH 组）对元音鼻音的感知，年龄在 4-12 岁之间。通过研究法语中元音鼻音的特征，本研究旨在更广泛地记录 CI 在处理以声学线索为特征的片段时的声学限制，这些线索需要最佳的频谱分辨率。研究了与儿童特征相关的各种因素（如年龄、听觉年龄、植入年龄和接受提示性言语的情况）对表现的影响，并研究了感知任务中刺激的声学特征。
对两组儿童进行了法语鼻音和口腔元音的识别和辨别任务：13 名植入人工耳蜗的儿童（CI 组）和 25 名听力正常的儿童（TH 组）分为三组（4-6 岁、7-9 岁和 10-12 岁）。法语鼻音元音与它们的口腔语音对应物（语音配对）以及在语音相似性方面最接近的口腔元音（语音配对）进行配对。对刺激的事后声学分析与感知表现相关联。
结果表明，听觉状况对两个任务的表现都有影响，CI 组的表现低于 TH 组。然而，CI 组的儿童的分数远高于机会水平，超过 80%。识别中最常见的错误是鼻音元音和语音上相近的口腔元音之间的替代以及音素/u/和其他口腔元音之间的混淆。在 CI 组中，语音对的辨别性能较低，结果差异很大。仅在 TH 儿童中观察到在识别法语鼻音时存在年龄效应，而在接受人工耳蜗植入的儿童中，发现了提示性言语练习和早期植入的积极影响。在我们的研究中，在不同的组中发现了性能和声学特征之间的差异联系，这表明在接受人工耳蜗植入的儿童中，选择性地使用某些被认为可以通过植入更好地传递的声学特征可以导致更好的感知表现。
本研究结果揭示了植入人工耳蜗的儿童在处理以精细频谱分辨率线索为特征的片段时存在特定的挑战。然而，我们研究中的 CI 儿童似乎通过利用各种被认为可以通过植入很好地传递的声学线索，如与刺激的时间分辨率相关的线索，有效地弥补了这些困难。
