A comparison of bottom-up and top-down training approaches: Brain responses as objective outcome measures of auditory training for improving speech perception in noise.

该项目通过了解语音感知的神经过程及其在衰老和听力损失后的变化，研究听觉训练方法在提高听力损失患者在噪音中语音理解方面的有效性。近年来，几项研究证明了听觉训练计划对听力受损者在噪音中提高言语理解的有效性。然而，不同的听众的个人收益不同，仍然不清楚哪种训练方法是最有效的。听力科学的研究发现，在听觉外围、沿听觉通路的声音处理阶段、皮层感知过程和认知大脑中，造成噪音中言语缺陷的多种原因。由于不同的训练方法与不同层次的加工相互作用，因此进一步研究的一个目标是记录和分析这些语音感知过程以及人脑中训练相关的变化。一个机会是解开导致听觉皮层变化的多模态自下而上和自上而下的神经机制。关键目标是在训练干预的同时，用脑磁图记录大脑的反应，以了解在哪种水平上训练提高噪音中的语音识别是有效的。在训练前和训练后的对照随机模式下，分为两个训练组。参与者将是健康的老年人（年龄在60至80岁之间），他们经历了正常的衰老相关的听力和噪音语音理解下降，但没有使用助听器。两组都将进行为期6周的两种不同的培训项目（自下而上和自上而下）。基于训练前、训练结束时以及训练结束后2个月以上的行为测量和听觉诱发反应来评估训练效果。作为听觉神经科学基础研究的一部分，本研究将为优化临床听觉康复过程中的个体护理提供重要信息。

The proposed project investigates the effectiveness of auditory training approaches for improving speech-in-noise understanding in people with hearing loss by gaining knowledge about neuronal processes underlying speech perception and its changes in ageing and after hearing loss. In recent years, several studies proved the efficacy of auditory training programs to improve speech understanding in noise in the hearing impaired. However, the individual benefit varies among the listeners, and still it is not clear which training method is the most effective. Research in hearing science identified multiple causes of speech-in-noise deficits at the auditory periphery, the stages of sound processing along the auditory pathway, cortical processes of perception and the cognitive brain. As different training approaches interact with processing at different levels, one aim in further research is to document and analyze these processes in speech perception and the training-related changes in the human brain. One opportunity is to disentangle the multi modal bottom-up and top-down neural mechanism contributing to changes in the auditory cortex. The key objective is to record brain responses with MEG in parallel to a training intervention to inform at which level the training to improve speech recognition in noise is effective. In the controlled randomized pre- to posttraining paradigm two training groups are conducted. Participants will be healthy older adults (age range 60 to 80 years) who experience normal aging related decline in hearing and speech-in-noise understanding, and however are not using hearing aids. Both groups will train over a period of 6 weeks with two different training programs (a bottom-up and a top-down). Evaluation of training outcome based on behavioral measures and auditory evoked responses before and at the end of the training as well as more than 2 months after the end of the training. As being part of fundamental research in auditory neuroscience, the study will generate important information to optimize individual care in the clinical auditory rehabilitation process.