Acoustic change complex in background noise: phoneme level and timing effects.
Acoustic change complex in background noise: phoneme level and timing effects.
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DOI：
10.14814/phy2.13464
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发表时间：
2017-11
影响因子：
2.5
通讯作者：
Maamor N
中科院分区：
文献类型：
--
作者：
Billings CJ;Grush LD;Maamor N
背景噪声对语音诱发皮层听觉诱发电位（CAEP）的影响可以提供对听觉系统生理学的深入了解。本研究的目的是确定背景噪声对音节内不同音素的神经编码的影响。研究人员记录了15名听力正常的年轻成年人对语音信号/s/、/s/和/s/的反应。信号以不同的信噪比（SNR）呈现。信噪比和上下文（孤立或音节内）的影响进行了分析，为两个音素。对于所有三种刺激，随着SNR的改善，潜伏期通常降低，幅度通常增加，并且不存在背景效应;然而，/潜伏期/响应的幅度是例外，显示没有SNR效应和显著的背景效应。/s/和/s/的差分编码可能是由电平和定时差异引起的。神经不应性可能导致在音节上下文中缺乏对幅度的鲁棒SNR效果。响应于/s/中的元音的跨SNR的稳定幅度表明（1）在低SNR下音节和噪声的声学特性和（2）在高SNR下由音素定时引起的不应效应的组合效应。结果提供了对不同背景噪声水平下多起始语音音节编码的见解，并与行为措施一起，可能有助于提高我们对噪声中语音感知困难的理解。
The effects of background noise on speech‐evoked cortical auditory evoked potentials (CAEPs) can provide insight into the physiology of the auditory system. The purpose of this study was to determine background noise effects on neural coding of different phonemes within a syllable. CAEPs were recorded from 15 young normal‐hearing adults in response to speech signals /s/, /ɑ/, and /sɑ/. Signals were presented at varying signal‐to‐noise ratios (SNRs). The effects of SNR and context (in isolation or within syllable) were analyzed for both phonemes. For all three stimuli, latencies generally decreased and amplitudes generally increased as SNR improved, and context effects were not present; however, the amplitude of the /ɑ/ response was the exception, showing no SNR effect and a significant context effect. Differential coding of /s/ and /ɑ/ likely result from level and timing differences. Neural refractoriness may result in the lack of a robust SNR effect on amplitude in the syllable context. The stable amplitude across SNRs in response to the vowel in /sɑ/ suggests the combined effects of (1) acoustic characteristics of the syllable and noise at poor SNRs and (2) refractory effects resulting from phoneme timing at good SNRs. Results provide insights into the coding of multiple‐onset speech syllables in varying levels of background noise and, together with behavioral measures, may help to improve our understanding of speech‐perception‐in‐noise difficulties.