Suzuki T, Horiuchi K
Scand Audiol. 1977;6(3):123-6. doi: 10.3109/01050397709043111.
The effect of high-pass filters on the vertex-positive brain stem response to tone pips at 500, 1000, 2000 and 4000 Hz was investigated in normal adults. The tape-recorded responses were averaged through high pass filters with 3 dB attenuation at 50, 100 and 200 Hz and with a slope of 6 dB/oct, and their amplitudes were compared with those of the averaged responses without filtering. These 3 filters reduced the amplitudes of the responses to 500-Hz tone pips by 3.3, 7.1 and 10.6 dB respectively. On the other hand, the mean attenuations caused by the same series of filters on the response amplitudes at 2000 Hz were only 0.2, 2.9 and 5.4 dB respectively. The responses at 4000 Hz were similar to those at 2000 Hz. This distinct difference in the effect of the high-pass filters suggests that the dominant frequency component of the brain stem response at 500 Hz is significantly lower than that at 2000 Hz and above. The results indicate that the use of a high-pass filter with cutoff frequency over 50 Hz is not recommended for recording the slow positive deflection of the brain stem response to low frequency tones.
在正常成年人中，研究了高通滤波器对500、1000、2000和4000赫兹短纯音诱发的顶点阳性脑干反应的影响。将磁带记录的反应通过在50、100和200赫兹处具有3分贝衰减且斜率为6分贝/倍频程的高通滤波器进行平均，并将其幅度与未滤波的平均反应幅度进行比较。这3种滤波器分别将对500赫兹短纯音反应的幅度降低了3.3、7.1和10.6分贝。另一方面，同一组滤波器对2000赫兹反应幅度造成的平均衰减分别仅为0.2、2.9和5.4分贝。4000赫兹的反应与2000赫兹的反应相似。高通滤波器效果的这种明显差异表明，500赫兹时脑干反应的主导频率成分明显低于2000赫兹及以上频率时的主导频率成分。结果表明，不建议使用截止频率超过50赫兹的高通滤波器来记录脑干对低频音调反应的缓慢正性偏转。
