声预处理对强噪声引起听力损伤保护作用的研究(英文)  

Effects of Sound Preconditioning on Hearing Loss from Low or Middle Frequency Noise Exposure

作　　者：刘亚光[1] 何延军 李道德 郑素贤 牛聪敏 

机构地区：[1]航天医学工程研究所,北京100094

出　　处：《航天医学与医学工程》2000年第5期313-317,共5页Space Medicine & Medical Engineering

摘　　要：目的探讨低频声预处理对强噪声及中频强噪声引起听力损伤的保护作用。方法两组声预处理组豚鼠在中心频率 0 .5kHz 85dB倍频带噪声作用下 ,连续暴露 4d(6h/d)后 ,在无噪声情况下恢复 3d。随后分别在中心频率 0 .5kHz和 1kHz 1 1 0dB的倍频带噪声下 ,暴露 1h。两组对照组豚鼠不经声预处理 ,分别直接暴露在中心频率 0 .5KHz和 1KHz 1 1 0dB的信频带噪声下 ,暴露 1h。然后观察各组在强噪声暴露后 ,听力恢复情况、红细胞膜丙二醛 (MDA)含量以及耳蜗外毛细胞铺片检查。结果强噪声暴露后 ,经过声预处理的两组动物 ,听阈偏移程度、红细胞膜MDA含量、耳蜗外毛细胞受损情况明显好于对照组 (P <0 .0 5)。结论声预处理不仅可以减轻随后同一频率段的强噪声 (0 .5kHz、1 1 0dB)引起的听力损伤 ,还可减轻随后稍高频率段的强噪声 (1kHz、1 1 0dB)引起的听力损伤 ,声预处理的保护作用可能是通过激活细胞抗氧化酶系统 ,抑制或减少毒性自由基产生 ,从而减轻毒性自由基对细胞膜的损伤。Objective To explore prior noise exposures or sound conditioning as a moderator of hearing loss produced by traumatic exposure to low or middle frequency noise. Method Two experimental groups of guinea pigs were conditioned using a 0.5 kHz octave band noise (OBN) at 85 dB,6 h/d for 4 d.The subjects were allowed to recover for 3 d after conditioning.Then the first group was exposed to a 0.5 kHz OBN at 110 dB for 1 h,the second group was exposed to 1 kHz OBN at 110 dB for 1 h.Two control groups received 0.5 kHz and 1 kHz OBN respectively at 110 dB for 1 h without prior sound conditioning. Result Hearing threshold shifts recorded at 48 h after the high level noise exposure in conditioned groups and control groups demonstrated that conditioning provided significant protection on hearing threshold shift from low or middle frequency noise exposure.Histological examination revealed significantly less hair cell loss in the conditioned than in the control groups.In addition,malondialdehyde(MDA) levels in red blood cell(RBC) of conditioned groups were significantly lower as compared with that of the control groups. Conclusion Low frequency conditioning provided significant protection not only on hearing threshold shift caused by noise of the same frequency,but also on that caused by middle frequency noise.

关 键 词：声预处理 听力保护 听力损伤 强噪声 LPO 航空 

分 类 号：R852.24[医药卫生—航空、航天与航海医学]