论文部分内容阅读
对１５只正常豚鼠的ＡＢＲ时域波形和频谱特征以及对１８只豚鼠通过脑干核团立体定位技术，毁损听觉通路各不同部位后的时域波形及频谱改变进行了分析。实验证明：正常豚鼠９０ｄＢＳＰＬ短声诱发的ＡＢＲ，呈现波Ⅰ、Ⅱ、Ⅲ、Ⅳ，通过平均功率谱分析，ＡＢＲ频谱范围在５０～２０００Ｈｚ，有３个谱能量集中区，ｆ０主峰中心频率为１８７．４７±２７．６８Ｈｚ，ｆ１为６９５．８２±１０３．４０Ｈｚ，ｆ２为１１０３．６７±８１．５５Ｈｚ。听觉通路不同部位毁损后，除影响一个时域主波形外，每个核团还不同程度地影响两个或两个以上波的形成。频谱图改变，有几个共同特点：（１）各谱峰中心频率向低频偏移；（２）谱分析带宽明显缩窄，高频截止区也向低频移动；（３）谱峰能量全面下降，甚至有的谱峰消失；（４）随毁损平面上行，谱能量损失减少，谱峰向低频区移动的程度降低。大多数核团对ｆ１有贡献，听神经及低位脑子对ｆ２的合成贡献较大，因此，应该认为ＡＢＲ频谱特征是整个听觉通路各部位的综合效应。
The time-domain waveform and spectral characteristics of ABR in 15 normal guinea pigs and the changes of time-domain waveform and frequency spectrum of 18 guinea pigs after their different parts of the auditory pathway were destroyed by brainstem nucleus stereotaxis were analyzed. Experiments show that: The ABR induced by 90 dB SPL in normal guinea pigs shows wave Ⅰ, Ⅱ, Ⅲ and Ⅳ. According to the average power spectrum analysis, the ABR spectrum is in the range of 50-2000 Hz, and there are 3 spectral energy concentration areas. The center frequency of f0 main peak is 187 .47 ± 27.68 Hz, f1 695.82 ± 103.40 Hz, f2 1103.67 ± 81.55 Hz. After different parts of the auditory pathway are damaged, besides affecting a time-domain main waveform, each nucleus also affects the formation of two or more waves to different degrees. Spectrum changes, there are several common characteristics: (1) the peak center frequency of each spectrum to the low frequency offset; (2) the spectral analysis bandwidth is significantly narrowed, high-frequency cut-off area also moves to the low frequency; (3) , And even some peaks disappear. (4) As the damage plane goes up, the spectral energy loss decreases and the peak of the spectrum shifts to the low frequency region. Most nuclei contribute to f1. The auditory nerve and lower brain contribute more to the synthesis of f2. Therefore, the ABR spectrum should be considered as the combined effect of various parts of the auditory pathway.