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

摘要 在美国，超过1/3的成年人因前庭障碍和听力问题而寻求医疗照顾。 损失;可以使跌倒风险增加三倍并对日常活动的参与产生深远影响的疾病 living.听力损失已被证明会降低平衡性能，并且可能是一个可改变的风险因素， 福尔斯。前庭功能减退的患者倾向于避免忙碌、忙乱、视觉复杂和嘈杂的环境 因为这些环境会引起头晕和失衡。虽然视觉效果对平衡的影响很好， 虽然我们知道，但对声音对平衡的重要性却知之甚少。为了寻找一种可能的机制来解释 我们所听到的和平衡控制之间的关系，一些研究表明，声音可能作为 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， 听力损失和平衡问题是通过未被发现的前庭缺陷来导航的。通过理解 听觉输入在平衡控制中的作用，我们可以更好地帮助这一大部分人口， 如有前庭障碍和听力损失，请就医。因此，迫切需要一个 系统研究了视觉和听觉同时扰动时的平衡性能， 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， 沉浸式环境的安装显示器（HMD）协议，结合了视觉效果的特定操作， 声音，包括生成的声音（即，白色噪声）和真实世界记录的声音（例如，驶近的火车 车站）。本研究将回答以下问题：（1）声音是否用于平衡，如果是，通过什么 机制？(2)单侧听力损失的人即使没有任何平衡问题， 前庭问题(3)那些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，将研究以下特定目的 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;目的2：确定 静态白色噪声可以改善动态视觉环境内的平衡的程度。我们期望 阐明声音在平衡控制中的作用。这一贡献将是重要的，因为该机制 听力损失和福尔斯之间潜在的联系需要更好地理解。我们的工作将告知 开发改进的平衡评估，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。 我们的工作也将通知新的康复结合声音和视觉在不同的发展 contexts. HMD和耳机的可负担性和便携性将允许未来转化为临床环境。

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.