A COMPARISON BETWEEN AUDITORY BRAINSTEM EVOKED RESPONSES (ABRs) AND FREQUENCY FOLLOWING RESPO SES (FFRs) IN NORMAL AND ABNORMAL GUINEA PIGS
正常和卡那霉素中毒豚鼠听觉脑干诱发反应及频率跟随反应的比较研究

A comparison between Auditory Brainstem Evoked Responses (ABRs) and Frequency Following Responses (FFRs) in normal and Kanamycin treated Guinea Pigw was made using threshold detection and spectrum analysis. The nonlinearity of FFRs became distinct as the stimulus frequency decreasd. An analysis of the data with Fast Fourier Trans-formation indicated that there was a primary peak wuth several other peaks at harmonic frequencys below 640Hz. We could easily identiky the thresholds of FFRs by the primary peak (its amplitude higher by 10 dB than that of backgroung noise) After medication of Kanamycin, the FFRs to high frequency sound stimulus were affected frist, with decreased amplitude and markedly increased threshold; whereas the FFRs to lower frequency sound stimulus were less affected. The amplitude of primary peaks of FFRs decreased significanyly or even no primary peaks could be seen for higher frequency stimuli. While the ABR thresholds still had no visible change. It suggests that the FFRs might be a more sensisive indicator than ABR in that case.