Mechanisms of Conductive Presbycusis in Humans

人类传导性老年性耳聋的机制 老年性耳聋是一种几乎普遍存在的疾病， 仅在美国就有数千万人，每年在全世界造成的损失超过7500亿美元。 老年性耳聋导致难以理解言语，听环境声音的问题，如果 如果得不到解决，可能会导致社会孤立。鉴于目前的人口趋势， 预计老年性耳聋会加速。尽管老年性耳聋很普遍， 其致病机制。老年性耳聋一直被认为是继发于感觉神经功能障碍， 但新的证据表明传导性病理学有助于老年性耳聋。 听力临床评估的主要方法是行为纯音（500- 8 kHz）测听。 扩展的高频空气传导测试（> 8 kHz）现在通常被执行， 高频声音对语音理解和声音定位的作用。不幸的是，临床骨 传导测试在4kHz时停止。在4kHz以上，标准刺激传感器的限制主要是 从20世纪50年代起一成不变，缺乏规范的骨传导标准限制了高频研究 传导损耗感觉神经性和传导性老年性耳聋之间的区别不是常规进行的， 但这是令人感兴趣的，因为：1）先前的工作表明中耳内的离散变化可导致 孤立的高频传导损失（即：正常的低频阈值）和2）我们的能力， 通过手术修复中耳。进一步调查年龄的患病率和功能意义- 相关的中耳变化是必要的，以确保老年性耳聋的新兴疗法是适当的， 指导。 新开发的无高频限制的骨传导传感器允许全面的骨传导 在高达16 kHz的频率下进行传导测试。新型传感器将有助于最终确定 存在临床相关的传导性或混合性老年性耳聋，阐明了老化的功能效应 中耳高频传导性听力损失的可靠测试的发展带来了影响 包括中耳手术后的听力评估。我们的目标是确定 传导性老年性聋的机制，并建立可靠的诊断方法， 传导性听力损失我们假设一部分老年性耳聋患者的听骨强度增加， 导致传导性或混合性高频听力损失。

Mechanisms of Conductive Presbycusis In Humans Age-related high frequency hearing loss (presbycusis) is a near universally experienced condition, affecting tens of millions of individuals in the United States alone and costing worldwide more than $750 billion per year. Presbycusis results in difficulty understanding speech, problems hearing environmental sounds and, if unaddressed, can lead to social isolation. Given current demographic trends, the societal burden of presbycusis is expected to accelerate. Despite the prevalence of presbycusis, much remains unknown about its etiologic mechanisms. Presbycusis has long been assumed to be secondary to sensorineural dysfunction, but emerging evidence suggests conductive pathology contributes to presbycusis. The principal method for clinical evaluation of hearing is behavioral pure tone (500-8kHz) audiometry. Extended high frequency air conduction testing (>8kHz) is now commonly performed given new knowledge on the role of high frequency sound for speech understanding and sound localization. Unfortunately, clinical bone conduction testing stops at 4kHz. Above 4kHz, limitations in standard stimulus transducers that are largely unchanged from the 1950s, and a lack of normative bone conduction standards limit study of high frequency conductive loss. Differentiation between sensorineural and conductive presbycusis is not routinely performed, but is of interest because: 1) prior work demonstrates discrete changes within the middle ear can lead to isolated high frequency conductive loss (ie: with normal low-frequency thresholds) and 2) our ability to surgically repair the middle ear. Further investigation into the prevalence and functional significance of age- related middle ear change is necessary to ensure emerging therapies for presbycusis are appropriately directed. Newly developed bone conduction transducers without high frequency limitations permit comprehensive bone conduction testing at frequencies up to 16kHz. Novel transducers will help to finally establish whether a clinically relevant conductive or mixed presbycusis exists, shedding light on the functional effects of the aging middle ear. Development of reliable testing for high frequency conductive hearing loss carries implications beyond presbycusis, including post-middle-ear-surgery hearing assessment. Our goal is to identify mechanisms of conductive presbycusis and to establish methods to reliably diagnose high frequency conductive hearing loss. We hypothesize that a subset of patients with presbycusis have increased ossicular compliance resulting in conductive or mixed high frequency hearing loss.