Dewey Rebecca Susan, Hall Deborah A, Guest Hannah, Prendergast Garreth, Plack Christopher J, Francis Susan T
Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom.
National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham, United Kingdom.
JMIR Res Protoc. 2018 Mar 9;7(3):e79. doi: 10.2196/resprot.9095.
Rodent studies indicate that noise exposure can cause permanent damage to synapses between inner hair cells and high-threshold auditory nerve fibers, without permanently altering threshold sensitivity. These demonstrations of what is commonly known as hidden hearing loss have been confirmed in several rodent species, but the implications for human hearing are unclear.
Our Medical Research Council-funded program aims to address this unanswered question, by investigating functional consequences of the damage to the human peripheral and central auditory nervous system that results from cumulative lifetime noise exposure. Behavioral and neuroimaging techniques are being used in a series of parallel studies aimed at detecting hidden hearing loss in humans. The planned neuroimaging study aims to (1) identify central auditory biomarkers associated with hidden hearing loss; (2) investigate whether there are any additive contributions from tinnitus or diminished sound tolerance, which are often comorbid with hearing problems; and (3) explore the relation between subcortical functional magnetic resonance imaging (fMRI) measures and the auditory brainstem response (ABR).
Individuals aged 25 to 40 years with pure tone hearing thresholds ≤20 dB hearing level over the range 500 Hz to 8 kHz and no contraindications for MRI or signs of ear disease will be recruited into the study. Lifetime noise exposure will be estimated using an in-depth structured interview. Auditory responses throughout the central auditory system will be recorded using ABR and fMRI. Analyses will focus predominantly on correlations between lifetime noise exposure and auditory response characteristics.
This paper reports the study protocol. The funding was awarded in July 2013. Enrollment for the study described in this protocol commenced in February 2017 and was completed in December 2017. Results are expected in 2018.
This challenging and comprehensive study will have the potential to impact diagnostic procedures for hidden hearing loss, enabling early identification of noise-induced auditory damage via the detection of changes in central auditory processing. Consequently, this will generate the opportunity to give personalized advice regarding provision of ear defense and monitoring of further damage, thus reducing the incidence of noise-induced hearing loss.
啮齿动物研究表明，噪声暴露可导致内毛细胞与高阈值听神经纤维之间的突触发生永久性损伤，而不会永久性改变阈值敏感性。这些通常被称为隐匿性听力损失的现象已在多个啮齿动物物种中得到证实，但对人类听力的影响尚不清楚。
我们由医学研究理事会资助的项目旨在通过研究终生累积噪声暴露对人类外周和中枢听觉神经系统造成损伤的功能后果，来解决这个尚未得到解答的问题。行为和神经成像技术正被用于一系列平行研究，旨在检测人类的隐匿性听力损失。计划中的神经成像研究旨在：（1）识别与隐匿性听力损失相关的中枢听觉生物标志物；（2）研究耳鸣或声音耐受性降低（这些情况常与听力问题并存）是否有任何累加作用；（3）探索皮层下功能磁共振成像（fMRI）测量与听性脑干反应（ABR）之间的关系。
年龄在25至40岁之间、在500赫兹至8千赫兹范围内纯音听力阈值≤20分贝听力级且无MRI禁忌症或耳部疾病迹象的个体将被纳入该研究。将通过深入的结构化访谈来估计终生噪声暴露情况。将使用ABR和fMRI记录整个中枢听觉系统的听觉反应。分析将主要集中在终生噪声暴露与听觉反应特征之间的相关性上。
本文报告了该研究方案。资金于2013年7月获批。本方案所述研究的入组工作于2017年2月开始，并于2017年12月完成。预计2018年得出结果。
这项具有挑战性的综合性研究有可能影响隐匿性听力损失的诊断程序，通过检测中枢听觉处理的变化实现对噪声性听觉损伤的早期识别。因此，这将有机会就提供耳部防护和监测进一步损伤给出个性化建议，从而降低噪声性听力损失的发生率。
