University of Copenhagen, Department of Nordic Studies and Linguistics, Speech Pathology and Audiology, Emil Holms Kanal 2, 2300, Copenhagen, Denmark; Lund University, Humanities Laboratory, Helgonabacken 12, Lund, 22100, Sweden.
University of Copenhagen, Department of Nordic Studies and Linguistics, Speech Pathology and Audiology, Emil Holms Kanal 2, 2300, Copenhagen, Denmark.
Hear Res. 2019 Mar 1;373:1-9. doi: 10.1016/j.heares.2018.12.001. Epub 2018 Dec 6.
This paper investigates the salience of speech contrasts in noise, in relation to how listening attention affects scalp-recorded cortical responses. The contrasts that were examined with consonant-vowel syllables, were place of articulation, vowel length and voice-onset time (VOT) and our analysis focuses on the correspondence between the effect of attention on the electrophysiology and the decrement in behavioral results when noise was added to the stimuli. Normal-hearing subjects (n = 20) performed closed-set syllable identification in no noise, 0, 4 and 8 dB signal-noise ratio (SNR). Identification in noise decreased markedly for place of articulation, moderately for vowel length and marginally for VOT. The same syllables were used in two electrophysiology conditions, where subjects attended to the stimuli, and also while their attention was diverted to a visual discrimination task. Differences in global field power between the attention conditions from each contrast showed that that the effect of attention was negligible for place of articulation. They implied offset encoding of vowel length and were early (starting at 117 ms), and of high amplitude (>3 μV) for VOT. There were significant correlations between the difference in syllable identification in no noise and 0 dB SNR and the electrophysiology results between attention conditions for the VOT contrast. Comparison of the two attention conditions with microstate analysis showed a significant difference in the duration of microstate class D. These results show differential integration of attention and syllable processing according to speech contrast and they suggest that there is correspondence between the salience of a contrast in noise and the effect of attention on the evoked electrical response.
本文研究了在听力注意力影响头皮记录的皮质反应的情况下，语音对比在噪声中的显著性。通过检查辅音-元音音节的对比，研究了发音部位、元音长度和嗓音起始时间（VOT），我们的分析重点是注意力对电生理学的影响与将噪声添加到刺激物中时行为结果的下降之间的对应关系。正常听力受试者（n=20）在无噪声、0、4 和 8 dB 信号噪声比（SNR）下进行闭音节识别。对于发音部位，识别在噪声中明显下降，对于元音长度中度下降，对于 VOT 则略有下降。相同的音节用于两种电生理条件，一种是受试者注意刺激，另一种是他们的注意力转移到视觉辨别任务时。从每个对比的注意条件之间的全局场功率差异表明，注意力的影响对于发音部位来说可以忽略不计。它们暗示了元音长度的起始编码，并且对于 VOT 是早期的（从 117ms 开始），幅度高（>3μV）。在无噪声和 0dB SNR 条件下的音节识别差异与 VOT 对比的注意力条件之间的电生理学结果之间存在显著相关性。与微状态分析的比较表明，微状态类 D 的持续时间存在显著差异。这些结果表明，根据语音对比，注意力和音节处理的整合是不同的，并且它们表明在噪声中对比的显著性与注意力对诱发电反应的影响之间存在对应关系。
