Production of nasal vowels in children with CI (Fagniart et al., 2024)

Purpose: The objective of the present study is to investigate nasal and oral vowel production in French-speaking children with cochlear implants (CIs) and children with typical hearing (TH). Vowel nasality relies primarily on acoustic cues that may be less effectively transmitted by the implant. The study investigates how children with CIs manage to produce these segments in French, a language with contrastive vowel nasalization.Method: The children performed a task in which they repeated sentences containing a consonant-vowel-consonant-vowel–type pseudoword, the vowel being a nasal or oral vowel from French. Thirteen children with CIs and 25 children with TH completed the task. Among the children with CIs, the level of exposure to Cued Speech (CS) was either occasional (CS−) or intense (CS+). The productions were analyzed through perceptual judgments and acoustic measurements. Different acoustic cues related to nasality were collected: segmental durations, formant values, and predicted values of nasalization. Multiple regression analyses were conducted to examine which acoustic features are associated with perceived nasality in perceptual judgments.Results: The perceptual judgments realized on the children’s speech productions indicate that children with sustained exposure to CS (CS+) exhibited the best identified and most distinct oral/nasal productions. Acoustic measures revealed different production profiles among the groups: Children in the CS+ group seem to differentiate between nasal and oral vowels by relying on segmental duration cues and variations in oropharyngeal configurations (associated with formant differences) but less through nasal resonance.Conclusion: The study highlights (a) a benefit of sustained CS practice for CI children for the intelligibility of nasal–oral segments, (b) privileged exploitation of temporal (segmental duration) and salient acoustic cues (oropharyngeal configuration) in the CS+ group, and (c) difficulties among children with CI in distinguishing nasal–oral segments through nasal resonance.Supplemental Material S1. Tables containing all the information concerning the statistical models performed and the fixed-effects power analyses described in the Results section.Fagniart, S., Delvaux, V., Harmegnies, B., Huberlant, A., Huet, K., Piccaluga, M., Watterman, I., & Charlier, B. (2024). Producing nasal vowels without nasalization? Perceptual judgments and acoustic measurements of nasal/oral vowels produced by children with cochlear implants and typically hearing peers. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2024_JSLHR-24-00083

本研究旨在探讨法语音儿童植入耳蜗（CI）与正常听力（TH）儿童在鼻音和口音元音产生方面的差异。鼻音元音的感知主要依赖于声学线索，而这些线索可能通过植入装置传递得不够有效。研究探讨了CI儿童如何在法语这种具有对比性鼻音元音的语言中产生这些音素。儿童们完成了一项任务，重复包含辅音-元音-辅音-元音类型伪词的句子，其中的元音为法语中的鼻音或口音元音。13名CI儿童和25名TH儿童完成了该任务。在CI儿童中，接触提示语（CS）的程度为偶尔（CS-）或强烈（CS+）。通过感知判断和声学测量分析了他们的产出。收集了与鼻音相关的不同声学线索：音节持续时间、共振峰值和鼻音预测值。进行多项回归分析，以考察哪些声学特征与感知鼻音在感知判断中相关。结果表明，持续接触CS（CS+）的儿童在识别和区分口音/鼻音产出方面表现最佳。声学测量揭示了不同组别之间的产出特征：CS+组的儿童似乎通过音节持续时间线索和口腔咽喉配置（与共振峰差异相关）来区分鼻音和口音元音，而较少依赖鼻音共鸣。结论指出：（a）对于CI儿童而言，持续的CS练习对于鼻音-口音音节的清晰度具有益处；（b）CS+组在利用时间（音节持续时间）和显著声学线索（口腔咽喉配置）方面具有优势；（c）CI儿童在通过鼻音共鸣区分鼻音-口音音节方面存在困难。补充材料S1：包含在结果部分描述的统计模型和固定效应功效分析的所有信息的表格。Fagniart, S.，Delvaux, V.，Harmegnies, B.，Huberlant, A.，Huet, K.，Piccaluga, M.，Watterman, I.，& Charlier, B.（2024）。无需鼻音的鼻音元音？耳蜗植入儿童和正常听力同伴产生的鼻音/口音元音的感知判断和声学测量。言语、语言和听力研究杂志。在线预发表。https://doi.org/10.1044/2024_JSLHR-24-00083