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.

尽管有100多年的实验研究，但我们对 噪音创伤的机制或保护的手段 噪音创伤，需要澄清。 最近的声音已经证明了对噪声创伤的保护 将豚鼠调节到低水平的长期声学刺激 （Canlon等，1988）。 这种声音调理改善了破坏性的 第二次噪声暴露的影响，预计会产生永久性 听力损失。 声音条件组显示出完全恢复，而 对照组继续显示20到30 dB的永久性听力损失。 这些发现对豚鼠并不特别，因为初步 结果表明，兔子对同一声音调节做出反应 时尚。 声音调节实验源自当前的概念 听觉生理学包括主动细胞机制。 自从 发现外毛细胞具有运动能力，已经是 建议它们是活跃的元素。 有人提出了声音 调理将增强外毛细胞的肌肉样能力 （Canlon等，1988）。 初步的形态学发现暗示着声音 调节可改善外毛细胞的代谢能力。 作为 这些令人兴奋的现象的结果，将在 为了检验我们的假设，即外部的内在特性 毛细胞直接受声调的影响。 电池 随时可用并已建立的电生理和形态学 可以应用测试以获取有关外部的特定信息 毛细胞。 将解决以下具体目标： （1）确定声音条件是否导致（i）形态改变 到Corti的器官； （ii）随后的损害模式改变 噪音曝光。 （2）测量声音调理后的外毛细胞电阻 分析临时阈值移位的大小和速率 恢复立方失真产品（2FL-F2）。 （3）确定声音条件如何保持频率选择性 听觉系统。 （4）确定需要哪些条件刺激的特征 用于保护噪声。 （5）确定传出系统是否在声音条件中起作用。 （6）确定中耳肌肉是否调节声音调节。 （7）量化声音调节如何修饰固有的生物学 毛细胞的特性。 这项研究不仅在理解人工耳蜗方面都很重要 机制，但在对噪声创伤的更深入了解时 以及如何减少它。