噪声暴露对大鼠短纯音与短声听觉脑干反应的影响

目的 研究噪声暴露对大鼠听觉脑干反应(ABR)的影响,及大鼠短声ABR(C-ABR)和短纯音ABR(Tb-ABR)的特点,以探讨Tb-ABR在听力评估中的价值.方法 将成年SD大鼠随机分为噪声组和正常组,每组7只(14耳).噪声组暴露于100 dB(SPL)白噪声,6 h/d,连续12周.噪声停止后24 h分别测定C-...

EFFECTS OF NOISE EXPOSURE ON CLICK- AND TONE BURST-EVOKED AUDITORY BRAINSTEM RESPONSE IN RATS

Objective To study the effects of noise exposure on click-evoked auditory brainstem responses（C-ABR） and tone burst-evoked ABR（Tb-ABR） in rats,so as to provide the reference for application of Tb-ABR to hearing evaluation.Methods Fourteen SD rats were divided into two groups,named the control group and the noise exposure group with seven rats per group（fourteen ears）.The noise exposure group were exposed to the white noise（100 dB（SPL）,6 h/day,12 weeks）.C-ABR and Tb-ABR（2,4,8,16,32 kHz） were measured 24 hours after noise exposure. Results The peak latency in normal rats was prolonged when the stimulate tone changed from 32 kHz to 2 kHz;the peak latency of Tb-ABR with any frequency was significantly longer than that of C-ABR（P0.01）;the hearing threshold at 16 kHz of Tb-ABR was the lowest,and the hearing was the best.The hearing loss in noise exposure group was most severe at 8 kHz（11 dB more than the control）.The thresholds of C-ABR and Tb-ABR of noise exposure group were higher than those of control group.The peak latency of wave Ⅳ and Ⅱ-Ⅳ interpeak latency of C-ABR of noise exposure group were significantly longer than those of control group（P0.01,P0.05）.No difference in peak latency and interpeak latency was observed at any frequency of tone burst between the noise exposure group and the control group.Conclusion The auditory thresholds,sensitivity at different frequency were different in rats.The effect of noise exposure on different frequency of hearing was also different.Tb-ABR was more accurate than C-ABR in estimating hearing loss.