PROTECTION AGAINST NOISE TRAUMA BY SOUND CONDITIONING

通过声音调节防止噪音伤害

• 批准号: 3218085
• 负责人: BARBARA CANLON
• 金额: $ 5.68万
• 依托单位: KAROLINSKA INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3218085
• 关键词: auditory discrimination; auditory stimulus; auditory threshold shift; conditioning; ear hair cell; guinea pigs; noise biological effect; organ of Corti; sound

Despite over 100 years of experimental research, our understanding of the mechanisms underlying noise trauma, or the means of protecting against noise trauma, needs to be clarified. Protection against noise trauma has been demonstrated recently by sound conditioning guinea pigs to a low level, long term acoustic stimulus (Canlon et al. 1988). This sound conditioning ameliorated the damaging effects of a second noise exposure that was expected to yield a permanent hearing loss. The sound conditioned group showed complete recovery, while the control group continued to show a 20 to 30 dB permanent hearing loss. These findings are not particular to the guinea pig, since preliminary results indicate that the rabbit responds to sound conditioning in the same fashion. The sound conditioning experiments originated from current concepts of auditory physiology which include active cellular mechanisms. Since the finding that the outer hair cells have a motile capacity, it has been suggested, that they are the active elements. It was proposed that sound conditioning would enhance a muscle-like capacity of the outer hair cells (Canlon et al. 1988). Preliminary morphological findings imply that sound conditioning improves the metabolic capacity of the outer hair cells. As a result of these exciting phenomena, numerous studies will be pursued in order to test our hypothesis that the intrinsic properties of the outer hair cells are directly affected by sound conditioning. A battery of readily available and established electrophysiological and morphological tests can be applied to obtain specific information concerning the outer hair cells. The following specific aims will be addressed: (1) To determine if sound conditioning results in (i) an altered morphology to the organ of Corti; (ii) an altered pattern of damage after subsequent noise exposure. (2) To measure outer hair cell resistance after sound conditioning by analyzing the magnitude of a temporary threshold shift and the rate of recovery of the cubic distortion product (2fl-f2). (3) To determine how sound conditioning preserves the frequency selectivity of the auditory system. (4) To determine what features of the conditioning stimulus are necessary for noise protection. (5) To determine if the efferent system plays a role in sound conditioning. (6) To determine if the middle ear muscles regulate sound conditioning. (7) To quantify how sound conditioning modifies the intrinsic biological properties of the hair cells. This research will be of importance not only in understanding cochlear mechanisms but also in developing a deeper understanding of noise trauma and how it may be possibly reduced.

尽管经过 100 多年的实验研究，我们对 噪声创伤的机制，或防止噪声损伤的方法 噪音创伤，需要澄清。 最近通过声音证明了对噪音创伤的保护作用 将豚鼠调节到低水平、长期的声刺激 （Canlon 等人，1988）。 这种声音调节改善了破坏性 第二次噪声暴露的影响预计会产生永久性的影响 听力损失。 声音调节组显示出完全康复，而 对照组继续表现出 20 至 30 分贝的永久性听力损失。 这些发现并不是豚鼠所特有的，因为初步 结果表明兔子对声音调节的反应相同 时尚。 声音调理实验源于当前的概念 听觉生理学，包括活跃的细胞机制。 自从 发现外毛细胞具有运动能力， 建议，它们是活性元素。 有人建议声音 调理会增强外毛细胞的类似肌肉的能力 （Canlon 等人，1988）。 初步的形态学研究结果表明，声音 调理可提高外毛细胞的代谢能力。 作为一个 这些令人兴奋的现象的结果，将进行大量研究 为了检验我们的假设，即外部的内在属性 毛细胞直接受到声音调节的影响。 一块电池 容易获得且已建立的电生理学和形态学 可以应用测试来获取有关外部的特定信息 毛细胞。 将实现以下具体目标： (1) 确定声音调节是否会导致 (i) 形态改变 柯蒂氏器； (ii) 随后发生的损坏模式的改变 噪音暴露。 (2) 测量声音调节后的外毛细胞电阻 分析临时阈值偏移的幅度和速率 立方畸变产物 (2fl-f2) 的恢复。 (3) 确定声音调节如何保持频率选择性 听觉系统的。 (4) 确定条件刺激的哪些特征是必要的 用于噪音防护。 (5) 确定传出系统是否在声音调节中发挥作用。 (6) 确定中耳肌肉是否调节声音调节。 (7) 量化声音调节如何改变内在的生物 毛细胞的特性。 这项研究不仅对于理解耳蜗具有重要意义 机制，同时也有助于加深对噪音创伤的理解 以及如何减少它。