空气负离子对白噪声及窄带噪声听力损伤的保护作用

PROTECTIVE EFFECTS OF NEGATIVE AIR IONS ON WHITE NOISE AND NARROW BAND NOISE-INDUCED HARING DAMAGE

本研究的目的为探索预防性吸入空气负离子对强噪声性听力损伤的保护作用和听力恢复规律。选用豚鼠暴露于１１８ｄＢＳＰＬ１ｈ的白噪声及２ｋＨｚ和４ｋＨｚ的窄带噪声，暴露前吸入空气负离子浓度０．９６×１０６～０．９９×１０６／ｃｍ３２ｈ／ｄ１１～１３ｄ。动态测定实验过程中豚鼠的皮层听觉反应阀指标。预先吸入空气负离子可减少白噪声性听力损失１７．９ｄＢ（噪声暴露停止后８ｈ与对照组比Ｐ＜０．０１），噪声暴露停止后８ｄ，动物听力大部分恢复至正常，而对照组则留有１８．２ｄＢ的永久性阈移；预先吸入空气负离子也可减少窄带噪声性听力损失，但听力都不能恢复至正常，并留有１７．８～２０．０ｄＢ的永久性阈移，而对照组则留有２７．８～３０．６ｄＢ的永久性阈移。结果提示，预防性吸入空气负离子对保护听力免遭噪声性损伤是有益的，对白嗓声性听力损伤具有更好的保护效果。

he present study was aimed to explore the protective effects of inha-lation of piegative air ions on intense noise-induced hearing damage and the pattern,of hearing recovery.The guniea pigs were exposed to white noise and narrow band noise (2kHz and 4kHz)at 118dB SPL for 1h after inha-lation of negative air ions with a concentration of 0.96×106-0.66×106/cm3 2h daily for 11-13d.Hearing threshold of the animals pre and post-inhala-tion of necrrsative air ions and 8h,48h,72h,8d,21d,31d,34d,35d after noise exposure Were determined using the auditory cortex evoked response to cli-ck by a computer averaging technique.The prophylactic inhalation of neg-ative air ions could alleviate the whie noise-induced hearing loss by 17.9 dB at 8h after noise cxposure (compared with control group P<0.01),and the hearing most animals recovered to pre-exposure level 8 days after noise exposure,whereas in the control group 18.2 dB permanent threshold shift remained.The prophylactic inhalation of negative air ions could also alleviate the narrow hand noise-induced hcaring loss,but the hearing could not recover to pre-exposure level and developed 17.8-20.0dB permanent thre-shold shift.Whereas in the control group 27.8-30.6dB permanent thresh-old shift remained.The results indicated that prophylactic inhalation of negative air ions was benificial in protection of hearing against noise and was nore effective on white noise-induced hearing loss.