Sensory integration of auditory and visual cues in diverse contexts given age, vestibular hypofunction and hearing loss

摘要 美国超过三分之一的成年人因前庭障碍和听力问题寻求医疗救治 损失；可使跌倒风险增加两倍，并对日常活动的参与产生深远影响的疾病 活着。听力损失已被证明会降低平衡能力，并可能是一种可修改的风险因素 瀑布。前庭功能低下的患者倾向于避免忙碌、忙碌、视觉复杂和嘈杂的环境 因为这些环境会引起头晕和失衡。虽然视觉上对平衡的影响很好 众所周知，人们对声音对平衡的重要性知之甚少。寻找一种可能的机制来解释 我们听到的声音和平衡控制之间的关系，一些研究表明，声音可能是 听觉锚，为平衡提供空间线索，类似于视觉。然而，这些研究中的大多数 测试了健康成年人对视觉受阻的声音的反应。也有可能的是， 听力损失和平衡问题是通过未发现的前庭缺陷来解决的。通过了解角色 在平衡控制方面的听觉输入，我们可以更好地帮助这一大部分人口 对于前庭紊乱和听力损失，请就医。因此，迫切需要一种 对同时受视觉和听觉干扰时的平衡性能进行系统研究， 类似于现实生活中的情况。 为了满足这一需求，我们的团队利用虚拟现实技术的最新进展，开发了一种头部 身临其境环境的安装式显示(HMD)协议，结合特定的视觉操作和 声音，包括生成的声音(即白噪声)和真实世界记录的声音(例如火车接近 一个站)。这项研究将回答以下问题：(1)声音是用来平衡的吗？如果是，是通过什么 机制？(2)单侧听力损失的个体即使没有平衡问题也会有平衡问题吗？ 前庭问题？(3)前庭功能丧失的人会因为声音而不稳定吗？为了解决这些问题， 在单侧外周前庭功能减退的个体中，将调查以下特定目标 (n=45)、单侧耳聋患者(n=45)和年龄匹配的对照组(n=45)：目的1：建立 在不同视觉环境中产生的声音和自然声音在姿势控制中的作用；目标2：确定 静态白噪声可以改善动态视觉环境中的平衡的程度。我们希望 阐明声音在平衡控制中的作用。这一贡献将是重大的，因为该机制 需要更好地了解听力损失和跌倒之间潜在的可能联系。我们的工作将告知 制定改进的平衡评估，特别是平衡测试是否需要包括姿势 对声音的反应。听力状况可能需要被视为跌倒风险增加的潜在指标。 我们的工作还将为将声音和视觉结合在一起的新康复技术的发展提供信息 上下文。HMD和耳机的可负担性和便携性将使未来能够转化为临床环境。

ABSTRACT More than 1/3 of adults in the United States seek medical attention for vestibular disorders and hearing loss; disorders that can triple one’s fall risk and have a profound effect on one’s participation in activities of daily living. Hearing loss has been shown to reduce balance performance and could be one modifiable risk factor for falls. Patients with vestibular hypofunction tend to avoid busy, hectic, visually complex, and loud environments because these environments provoke dizziness and imbalance. While the visual impact on balance is well known, less is known about the importance of sounds for balance. In search for a possible mechanism to explain a relationship between what we hear and balance control, some studies suggested that sounds may serve as an auditory anchor, providing spatial cues for balance, similar to vision. However, the majority of these studies tested healthy adults’ response to sounds with blocked visuals. It is also possible that a relationship between hearing loss and balance problems is navigated via an undetected vestibular deficit. By understanding the role of auditory input in balance control, we can be better equipped to help this large portion of the population who seek medical attention for vestibular disorders and hearing loss. Therefore, there is a critical need for a systematic investigation of balance performance in response to simultaneous visual and auditory perturbations, similar to real-life situations. To answer this need, our team used recent advances in virtual reality technology and developed a Head Mounted Display (HMD) protocol of immersive environments, combining specific manipulations of visuals and sounds, including generated sounds (i.e., white noise) and real-world recorded sounds (e.g., a train approaching a station). This research will answer the following questions: (1) Are sounds used for balance and if yes, via what mechanism? (2) Do individuals with single-sided hearing loss have a balance problem even without any vestibular issues? (3) Are those with vestibular loss destabilized by sounds? To address these questions, the following specific aims will be investigated in individuals with unilateral peripheral vestibular hypofunction (n=45), individuals with single-sided deafness (n=45), and age-matched controls (n=45): Aim 1: Establish the role of generated and natural sounds in postural control in different visual environments; Aim 2: Determine the extent to which a static white noise can improve balance within a dynamic visual environment. We expect to clarify the role of sounds in the control of balance. This contribution will be significant because the mechanism underlying possible link between hearing loss and falls needs to be better understood. Our work will inform the development of improved balance assessments, specifically whether balance tests need to include postural responses to sounds. Hearing status may need to be considered as a potential indicator of increased fall risk. Our work will also inform the development of new rehabilitation combining sounds and visuals in different contexts. HMDs and headphones affordability and portability will allow future translation to a clinical setting.