摘要
目的探讨听觉系统产生的抗噪声损伤能力是否依赖于条件声暴露的时程。方法将听力正常的31只杂色雄性豚鼠（250-400g）：按噪声暴露的时程不同随机分为四组，即条件声暴露1天组（n=8），条件声暴露7天组（n=8），条件声暴露14天组（n=7）及未经条件声暴露的对照组（n=8）。条件声为中心频率为1kHz、强度为95dBSPL的倍频程噪声，每天暴露8小时。条件声暴露结束5天后再将豚鼠暴露于相同频谱强度为115dBSPL的强噪声中连续暴露48小时。并于条件声暴露前、条件声暴露结束当天、条件声暴露结束后第5天、强噪声暴露后当天以及强噪声暴露后第14天分别测试动物的ABR阚。结果强噪声暴露48小时后当天，经过条件声暴露的三组动物的TTS（暂时性阔移）均较对照组低。条件声暴露1天组动物的平均闻移为48．4dB，虽然较对照组的50．5dB低，但差异无统计学意义（P〉0．05）。14天后条件声暴露1天组和对照组的PTS（永久性阈移）分别为27．2和31．3dB，差异无统计学意义（P〉0．05）。条件声暴露7天组动物在强噪声暴露后其丁rS和PTS分别为31．1和17．0dB，均明显低于对照组和条件声暴露1天组（P〈0．05）。条件声暴露14天组在强噪声暴露后其TTS和PTS分别为32．3和19．1dB，也明显低于对照组和条件声暴露1天组（P〈0．05）。结论间歇性的条件声暴露可以诱导豚鼠听觉系统产生抵抗噪声损伤的能力并与条件声暴露的时程有关系。
Objective To indicate whether or not the ability of the auditory system to agaist the noise trauma depend on the duration of conditioning exposure, Method Thirty- one guinea pigs served as subjects, the animals（250400g） were randomly divided into four groups according to the duration of conditioning exposure（animals were conditioning exposed to 1kHz at 95dBSPLwide band noise for 8 hours per day）, the first group（8 animals） received only one day（8h） conditioning exposure, the second （8 animals） and the third group（？ animals） were conditioning exposed for 7d（56h） or 1.4d（112h） respectively, the fourth group（8 animals） received no conditioning exposure served as control group, Five days after the last ＂conditioning＂ exposure, all conditioned animals were re- exposed to the same spectrum at 115dBSPL for 48h, the control group animals were exposed only to the higher level noise, TTS（temporary threshold shift） and PTS （permanent threshold shift）were measured at the planning time prior, Result The results showed that the average TTS in all the three conditioned groups were lower than that of the control group. The difference of TTS between the first group and the control group was insignificant （p〉0.05） while the differences between the control and the other two groups were significant（ p 〈0.05）. The second group animals showed the lowest TTS（about 20dB lower than the control＇s） among the four groups. At 14th day after noise trauma, PTS were measured, the TS showed substantial recovery in all animals, the degree of recovery of TS was consistent, PTS in the first, second, third and the control group was 27.2, 17.0, 19. 1 and 31.3rib respectively. The difference of PTS between the first and the control group was insignificant（ p 〉0.05）while the differencea between the control and the other two groups were significant（ p 〈0.05）. Conclusion Interrupted conditioning exposure can make auditory system of guinea pig more resistance to noise trauma a
出处
《医学信息（手术学分册）》
2006年第1期43-45,共3页
Medical Information Operations Sciences Fascicule
关键词
条件声
暴露时程
坚韧化
阈移
Conditioning sound
exposure. Duration
Toughening
Threshold shift
