Role of the Auditory Efferent System in Auditory Perceptual Learning

听觉传出系统在听觉感知学习中的作用

• 批准号: 9049094
• 负责人: Ian B. Mertes
• 金额: $ 5.51万
• 依托单位: LOMA LINDA VETERANS ASSN RESEARCH & EDUC
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2016-08-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9049094
• 关键词: Adult; Age; Amplifiers; Auditory; Auditory system; Biological; Biological Markers; Brain; Contralateral; Control Groups; Detection; Ear; Elderly; Environment; Exhibits; Hearing; Hour; Individual; Intervention; Learning; Masks; Measurement; Measures; Medial; Mediating; Noise; Outer Hair Cells; Participant; Perceptual learning; Performance; Phase; Physiological; Physiological Processes; Play; Population; Process; Randomized; Recruitment Activity; Reflex action; Role; Signal Transduction; Source; Speech; Speech Perception; System; Testing; Time; Training; Training Programs; Visit; base; experience; hearing impairment; improved; insight; medial superior olive; neurotransmitter release; noise perception; otoacoustic emission; public health relevance; response; sound; success

 DESCRIPTION (provided by applicant): The medial olivocochlear (MOC) branch of the auditory efferent system reduces the amplification mechanism of the outer hair cells, which may aid in signal detection in noise (Guinan, 2006). Because the MOC system is activated reflexively by sound (MOC reflex, or MOCR), its activity can be assessed by measuring otoacoustic emissions (OAEs), low-level sounds that are byproducts of outer hair cell-based amplification, and then repeating the OAE measurements with noise presented to the contralateral ear (e.g., Berlin et al., 1993). The MOCR activation by the noise reduces the amplitudes of OAEs (MOCR inhibition). Speech perception in noise performance is correlated with the magnitude of MOCR inhibition (e.g., Kumar & Vanaja, 2004), further suggesting that the MOCR is involved with hearing in noise. Previous studies have typically examined the relationship between MOCR inhibition and speech perception in noise using a single speech task. The first specific aim of the current study is to more clearly delineate this relationship by assessing speech perception in noise using multiple speech tasks (word and sentence recognition using either adaptive or fixed signal-to-noise ratios) in the same group of subjects. Both MOCR inhibition and speech perception abilities may be improved as a result of auditory training (de Boer & Thornton, 2008; Kumar et al., 2010), suggesting that MOCR inhibition may be a biomarker for auditory perceptual learning. Biomarkers may be used to identify the physiologic processes impacted by auditory training and may be predictive of the benefit obtained from training (de Boer & Thornton). These studies only examined young normal-hearing participants, so the generalizability to populations with speech-in-noise difficulties (e.g., older and hearing-impaired adults) is not known. The second specific aim of this study is to determine whether MOCR inhibition serves as a biomarker of auditory perceptual learning in a group of older adults with normal hearing or mild hearing loss. A total of 30 subjects ages 50-89 will be recruited. Subjects will be randomly assigned to an experimental or control group. The experimental group will undergo 15 hours of auditory training occurring across 10 lab visits. Auditory training will target the identification of phonemes and sentences in background noise in an adaptive manner. MOCR inhibition and speech perception in noise will be measured before, during, and after training. The control group (no training) will complete 4 visits, where MOCR inhibition and speech perception in noise will be measured to establish test-retest reliability. It is hypothesize that MOCR inhibition will be significantly correlated with all speech perception measures, with the largest correlations occurring for the more challenging signal-to-noise ratio conditions. It is also hypothesized that the change in MOCR inhibition across time in the experimental group will be significantly correlated with the changes seen in speech perception. The results of this study will have implications for understanding the physiologic mechanisms involved in speech-in-noise perception and for objectively assessing the benefit from auditory training.

 描述(申请人提供)：听觉传出系统的内侧橄榄耳蜗支(MOC)减少了外毛细胞的放大机制，这可能有助于在噪声中检测信号(Guinan，2006)。由于MOC系统是由声音(MOC反射，或MOCR)反射激活的，因此可以通过测量耳声发射(OAEs)来评估其活动，OAEs是基于外毛细胞的放大的副产品，然后利用提供给对侧耳朵的噪声重复OAE测量(例如，柏林等人，1993)。噪声对MOCR的激活降低了OAEs的幅度(MOCR抑制)。噪声操作中的言语知觉与MOCR抑制的大小相关(如Kumar&Vanaja，2004)，进一步表明MOCR与噪声中的听力有关。以前的研究通常使用单一的语音任务来考察MOCR抑制和噪声中的语音感知之间的关系。的第一个具体目标 目前的研究是通过在同一组受试者中使用多个语音任务(使用自适应或固定信噪比进行单词和句子识别)来评估在噪声中的语音感知，以更清楚地描述这种关系。听觉训练可以提高MOCR抑制能力和言语知觉能力(De Boer&Thornton，2008；Kumar et al.，2010)，这表明MOCR抑制可能是听觉知觉学习的生物标志物。生物标记物可用于识别受听觉训练影响的生理过程，并可预测训练的益处(de Boer&Thornton)。这些研究只调查了听力正常的年轻参与者，因此在噪音中有言语困难的人群(例如，老年人和听力受损的人)的概括性 (成人)是未知的。这项研究的第二个具体目的是确定在一组听力正常或轻度听力损失的老年人中，MOCR抑制是否可以作为听觉知觉学习的生物标志物。将招募30名年龄在50-之间的受试者。受试者将被随机分配到试验组或控制组。试验组将在10次实验室访问中接受15个小时的听觉训练。听力训练将以 自适应地识别背景噪声中的音素和句子。在训练前、训练中和训练后将测量噪声中的MOCR抑制和言语知觉。对照组(不进行训练)将完成4次访问，测量MOCR抑制和噪声中的言语知觉，以建立重测信度。假设MOCR抑制将与所有语音感知测量显著相关，其中最大的相关性发生在更具挑战性的信噪比条件下。它是 还假设，实验组中MOCR抑制随时间的变化将与语言知觉的变化显著相关。这项研究的结果将对理解噪声中语音感知的生理机制和客观评估听觉训练的益处具有重要意义。