摘要
强噪声暴露可致听力损伤，产生暂时性或永久性听阈偏移。听力损伤程度除和噪声暴露参数有关外，还和听觉系统本身的生理和代谢状态有关［１］。实验证实，外毛细胞在声刺激后有类似耳肌收缩样作用［２］，但这种收缩作用对听力的生物效应还不清楚。低强度无损害性噪声暴露对后来的强声刺激是否有保护作用，国内尚未见有报导。本实验以豚鼠为实验动物，预先暴露低剂量安全噪声，随后暴露能产生听觉损害的强噪声，观察前者对后者的听力损伤有无保护作用。
The protection against noise trauma by preexposure to low noise was investigated, 19 guinea pigs, divided into test (n=9) and control (n=10 ) group, were used as subjects. The animals of the test group were preexposed to go dB SPL white noise (2h/d) for 10 days,then were exposed to 110 dB SPL white noise for 30 min. The control group was exposed to 110 dB white noise for 30 min only and not pre-exposed to low level noise. The results showed that (1). The threshold shifts of the test group produced by the low level noise were diminished with the exposing days, i.e. the threshold shifts at the second day were 12 dB while at the five and at the tenth day were 7 dB and 5 dB respectively. (2). The threshold shifts of the test group produced by the high level noise were mush smaller than that of the control group between O.5 to 48h post exposure. There was significant difference between the two groups. It is clear that preexposure to low level noise ameliorated the damaging effects of a second intensive noise exposure on hearing.
出处
《声学技术》
CSCD
1990年第3期10-12,共3页
Technical Acoustics
