KU Leuven - University of Leuven, Department of Neurosciences, Research Group Experimental ORL (ExpORL), Leuven, Belgium.
KU Leuven - University of Leuven, Department of Neurosciences, Research Group Experimental ORL (ExpORL), Leuven, Belgium.
Neurobiol Aging. 2019 Feb;74:202-212. doi: 10.1016/j.neurobiolaging.2018.10.008. Epub 2018 Oct 11.
Hearing impairment goes with speech perception difficulties, presumably not only because of poor hearing sensitivity but also because of altered central auditory processing. Critical herein is temporal processing of the speech envelope, mediated by synchronization of neural activity to the envelope modulations. It has been suggested that hearing impairment is associated with enhanced sensitivity to envelope modulations which, in turn, relates to poorer speech perception. To verify this hypothesis, we performed a comparative electrophysiological study in hearing-impaired (HI) and normal-hearing (NH) human listeners of three age groups, investigating neural envelope encoding. HI young and middle-aged adults showed enhanced neural synchronization to envelope modulations relative to NH controls, particularly when stimulus audibility was corrected for. At an older age, the degree of neural synchronization was similar for HI and NH persons, yet HI persons showed a synchronization asymmetry toward the right hemisphere. This study demonstrates that hearing impairment is characterized by changes in the neural encoding of envelope modulations, the nature of which varies with age.
听力障碍伴随着言语感知困难，这可能不仅是由于听力敏感度差，还因为中枢听觉处理改变。关键在于言语包络的时程处理，这由神经活动对包络调制的同步介导。有人认为，听力障碍与对包络调制的敏感性增强有关，而这种敏感性又与言语感知能力下降有关。为了验证这一假设，我们对三组年龄的听力受损（HI）和正常听力（NH）的人类受试者进行了一项比较电生理学研究，以研究神经包络编码。HI 的年轻和中年成年人相对于 NH 对照组表现出对包络调制的神经同步增强，尤其是在对刺激可听度进行校正时。在较老的年龄，HI 和 NH 个体的神经同步程度相似，但 HI 个体表现出对右半球的同步不对称性。这项研究表明，听力障碍的特征是包络调制的神经编码发生变化，其性质随年龄而变化。
