Hwang Juen-Haur, Wu Chang-Wei, Chen Jyh-Horng, Liu Tien-Chen
Department of Otolaryngology, Buddhist Dalin Tzu-Chi General Hospital, Chiayi, Taiwan.
Acta Otolaryngol. 2006 Sep;126(9):916-20. doi: 10.1080/00016480500546375.
Noise-induced masking has different effects on the two hemispheres during speech listening. Auditory-associated cortices in the left hemisphere were more affected by masking than the right side. However, activation of primary and secondary auditory cortices was not affected in both sides under the masking with high signal to noise ratio.
The purpose of this study was to investigate the effects of masking on the central auditory system during speech listening in white noise.
Twelve healthy young subjects with normal hearing participated in this study. Functional magnetic resonance imaging (fMRI) was performed while subjects were listening to speech sounds alone and speech plus white noise binaurally.
In humans, the activation of several regions including the middle parts of the superior and middle temporal gyri, parahippocampal gyrus, cuneus and thalamus of the left hemisphere was significantly reduced under the masking paradigm with +5 dB signal to noise ratio. In addition, reduced activation was also found at the lingual gyrus, anterior and middle parts of the superior temporal gyrus (STG), uncus, fusiform gyrus, and inferior frontal gyrus of the right hemisphere during masking.
在言语聆听过程中，噪声诱发的掩蔽对两个半球有不同影响。左半球与听觉相关的皮层比右侧受掩蔽的影响更大。然而，在高信噪比掩蔽条件下，两侧的初级和次级听觉皮层的激活均未受到影响。
本研究旨在探讨在白噪声环境下言语聆听过程中掩蔽对中枢听觉系统的影响。
12名听力正常的健康年轻受试者参与了本研究。在受试者单耳聆听语音以及双耳聆听语音加白噪声时进行功能磁共振成像（fMRI）。
在人类中，在信噪比为 +5 dB 的掩蔽范式下，包括左半球颞上回和颞中回中部、海马旁回、楔叶和丘脑等几个区域的激活显著降低。此外，在掩蔽期间，右半球的舌回、颞上回（STG）前部和中部、钩回、梭状回和额下回也发现激活减少。
