强噪声引起听觉脑干慢波电位的即时性增大效应

Immediate enhancing effect of slow wave of brainstem auditory evoked potential induced by intensive noise exposure

目的：观察强噪声对听觉脑干慢波电位波幅的即时性增大效应。方法：将３６只豚鼠分３组，分别暴露在９５、１１５、１２５ｄＢＳＰＬ不同声强的噪声中，３０ｍｉｎ后，立即检测听觉脑干慢波电位（ＳＷ－ＢＡＥＰ）正相波的波幅。结果：在９５ｄＢＳＰＬ组，可见１ｋＨｚ短纯音诱发的ＳＷ－ＢＡＥＰ波幅明显增大（Ｐ＜０．０５），在１１５ｄＢＳＰＬ组，增大更加明显（Ｐ＜０．０１）；在１２５ｄＢＳＰＬ组，短声及１、４ｋＨｚ短纯音诱发的ＳＷ－ＢＡＥＰ波幅均有减小趋势，但只４ｋＨｚ差异显著（Ｐ＜０．０５）。结论：表明只有在适当强度的噪声暴露后，才能引起ＳＷ－ＢＡＥＰ正相波的波幅即时性增大，并具有频率特性；即时性增大效应的出现，常预示出现暂时性阈移（ＴＴＳ），因而可用于永久性阈移（ＰＴＳ）的早期预测。

Objective:To observe the immediate enhancing effect of slow wave amplitude of brainstem auditory evoked potential after intensive noise exposure.Methods:Thirty-six guinea pigs were divided into three groups,and exposed to different intensive noise at 95,115 and 125 dB SPL respectively for thirty minutes,and the amplitude of positive wave of SW-BAEP within five minutes after exposure was measured.Results:In group of 95 dB SPL,the amplitude evoked by 1 kHz tone burst was augmented evidently (P<005);in group of 115 dB SPL,the amplitude was increased obviously (P<001);in group of 125 dB SPL,the amplitude induced by click and 1,4 kHz tone burst were all tended to reduce,but only the difference was obviously induced by 4 kHz tone butrst (P<005).Conclusion:The result indicated that only after appropriate intensive noise exposure,the immediate enhancing effect of amplitude of positive wave of SW-BAEP can be evoked,and with frequency characteristics;appearance of the immediate enhancing effect usually predict emergence of temporary threshold shift (TTS),as a result it can be applied to early forecast of perpetual threshold shift(PTS). 