噪声习服对听觉损伤保护作用

目的探讨噪声习服对听觉损伤的保护作用。方法取健康成年豚鼠40只，随机分为正常对照组、噪声习服组、噪声损伤暴露组和噪声习服后损伤暴露组。建立噪声习服实验动物模型。采用听觉电生理测试和耳蜗基底膜铺片的方法，分别测定听性脑干反应（ABR）阈值及毛细胞缺失率的变化。结果噪声习服暴露对其后强噪声损伤暴露引起的听力损失产生了13dB的保护作用。耳蜗基底膜铺片显示，本实验中暴露引起的毛细胞缺失较明显，习服后损伤暴露组与直接损伤的暴露组相比基底膜第Ⅰ、Ⅱ圈的毛细胞缺失减少。结论采用适宜的噪声暴露参数，噪声习服暴露可对其后强噪声损伤暴露引起的听力损失产生保护作用。噪声暴露引起的毛细胞形态学改变包括细胞缺失和非致死性细胞损伤。噪声习服暴露后减少其后强噪声损伤暴露引起的毛细胞缺失。

Protection effect of sound conditioning on acoustic trauma

Objective To investigate the protection of sound conditioning on acoustic trauma.Methods Forty healthy guinea pigs with normal Preyer's reflex were used.The animals were randomly divided into four groups:normal group,conditioning noise group,high-level noise group and conditioning noise followed by high-level noise group.Sound conditioning experimental model of animals was established.Auditory brainstem response(ABR) threshold was tested with auditory electrical physiology method.Hair cell loss was measured by surface preparation technique.Results Conditioning noise exposure protected hearing loss by 13?dB from an acoustic trauma that resulted in the following high-level noise exposure.Cochlear surface preparations indicated that the loss of hair cells induced by noise exposure was obvious.A significant difference was observed between high-level noise group and conditioning noise followed by high-level noise group at the first and the second turn of the basilar membrane.Conclusion Sound conditioning experimental model of animals is established successfully with appropriate noise conditions.Morphological changes in hair cell stem from noise exposure includes hair cell loss and other impairments instead of hair cell death.Sound conditioning can decrease hair cell loss induced by the following high-level noise exposure