Brain and Cognition Research Centre, University of Toulouse Paul Sabatier, Toulouse, France; Brain and Cognition Research Centre, CNRS-UMR, 5549, Toulouse, France; Cochlear France SAS, Toulouse, France.
Hôpital Pierre-Paul Riquet, CHU Toulouse Purpan, France.
Neuropsychologia. 2020 Dec;149:107683. doi: 10.1016/j.neuropsychologia.2020.107683. Epub 2020 Nov 17.
Unilateral hearing loss (UHL) generates a disruption of binaural hearing mechanisms, which impairs sound localization and speech understanding in noisy environments. We conducted an original study using fMRI and psychoacoustic assessments to investigate the relationships between the extent of cortical reorganization across the auditory areas for UHL patients, the severity of unilateral hearing loss, and the deficit in binaural abilities. Twenty-eight volunteers (14 UHL patients) were recruited (twenty-two females and six males). The brain imaging analysis demonstrated that UHL induces a shift in aural dominance favoring the better ear, with a cortical reorganization located in the non-primary auditory areas, ipsilateral (same side) to the better ear. This reorganization is correlated not only to the hearing loss severity but also to spatial localization abilities. A regression analysis between brain activity and patient's performance clearly showed that the spatial hearing deficit was linked to a functional alteration of the posterior auditory areas known to process spatial hearing. Altogether, our study reveals that UHL alters the dorsal auditory stream, which is deleterious to spatial hearing.
单侧听力损失 (UHL) 会破坏双耳听觉机制，从而影响嘈杂环境中的声音定位和言语理解。我们使用 fMRI 和心理声学评估进行了一项原创研究，以调查 UHL 患者听觉区域皮质重组的程度、单侧听力损失的严重程度以及双耳能力缺陷之间的关系。共招募了 28 名志愿者（14 名 UHL 患者）（22 名女性和 6 名男性）。脑成像分析表明，UHL 会导致听觉优势偏向于较好的耳朵，这种皮质重组位于对侧（较好耳朵的同侧）非主要听觉区域。这种重组不仅与听力损失的严重程度相关，还与空间定位能力相关。大脑活动与患者表现之间的回归分析清楚地表明，空间听力缺陷与已知处理空间听力的后听觉区域的功能改变有关。总的来说，我们的研究表明，UHL 改变了背侧听觉流，这对空间听力有不利影响。
