Reilly Kevin J
Department of Audiology and Speech Pathology, College of Health Professions, University of Tennessee Health Science Center, Memphis.
J Speech Lang Hear Res. 2020 Apr 27;63(4):1002-1017. doi: 10.1044/2020_JSLHR-19-00345. Epub 2020 Apr 15.
Purpose This study investigated vowel and sibilant productions in noise to determine whether responses to noise (a) are sensitive to the spectral characteristics of the noise signal and (b) are modulated by the contribution of vowel or sibilant contrasts to word discrimination. Method Vowel and sibilant productions were elicited during serial recall of three-word sequences that were produced in quiet or during exposure to speaker-specific noise signals. These signals either masked a speaker's productions of the sibilants /s/ and /ʃ/ or their productions of the vowels /a/ and /æ/. The contribution of the vowel and sibilant contrasts to word discrimination in a sequence was manipulated by varying the number of times that the target sibilant and vowel pairs occurred in the same word position in each sequence. Results Spectral noise effects were observed for both sibilants and vowels: Responses to noise were larger and/or involved to more acoustic features when the noise signal masked the acoustic characteristics of that phoneme class. Word discrimination effects were limited and consisted of only small increases in vowel duration. Interaction effects between noise and similarity indicated that the phonological similarity of sequences containing both sibilants and/or both vowels influenced articulation in ways not related to speech clarity. Conclusion The findings of this study indicate that sensorimotor control of speech exhibits some sensitivity to noise spectral characteristics. However, productions of sibilants and vowels were not sensitive to their importance in discriminating the words in a sequence. In addition, phonological similarity effects were observed that likely reflected processing demands related to the recall and sequencing of high-similarity words.
目的 本研究调查了在噪声环境中元音和咝音的发音情况，以确定对噪声的反应是否：（a）对噪声信号的频谱特征敏感；（b）受元音或咝音对比对单词辨别贡献的调节。方法 在对安静环境中或暴露于特定说话者噪声信号时产生的三字序列进行系列回忆过程中，引出元音和咝音的发音。这些信号要么掩盖说话者发出的咝音/s/和/ʃ/，要么掩盖其发出的元音/a/和/æ/。通过改变目标咝音和元音对在每个序列中同一单词位置出现的次数，来操纵元音和咝音对比对序列中单词辨别的贡献。结果 观察到咝音和元音都存在频谱噪声效应：当噪声信号掩盖该音素类别的声学特征时，对噪声的反应更大和/或涉及更多声学特征。单词辨别效应有限，仅表现为元音时长略有增加。噪声与相似度之间的交互效应表明，同时包含咝音和/或元音的序列的语音相似度以与语音清晰度无关的方式影响发音。结论 本研究结果表明，言语的感觉运动控制对噪声频谱特征表现出一定的敏感性。然而，咝音和元音的发音对它们在辨别序列中单词的重要性并不敏感。此外，观察到语音相似度效应，这可能反映了与高相似度单词的回忆和排序相关的加工需求。
