Thümmler I, Tietze G
Scand Audiol. 1984;13(2):129-37. doi: 10.3109/01050398409043051.
Derived acoustically evoked brainstem responses determined by narrow-band and notched-noise masking at 2000 Hz frequencies and below were investigated and compared with those obtained in the use of the common high-pass masking technique. With all three masking methods a dominant late wave Wa could be detected at less than or equal to 1 600 Hz centre frequencies of the derived band and this wave is typical of the excitation of the apical section of the cochlea. The latency of this wave increases when the centre frequency is decreased at a constant stimulation level. For a constant centre frequency of the derived band the latency of wave Wa increases when the stimulation level of the click and in parallel to that the masking level is decreased. Wave Wa could be found near the hearing threshold in all three masking methods. The notched-noise masking method offers major advantages provided that full masking of the frequency regions above and below the notch frequency range is carried out. A direct frequency-specific stimulation takes place and there is no need for subtracting one response from a second one. This reduces the investigation time and the memory capacity of the measuring device. The advantages and applicability of the notched-noise masking method have to be re-checked in patients with different frequency-dependent loss of hearing.
研究了通过2000Hz及以下频率的窄带和带陷噪声掩蔽所确定的衍生听觉诱发脑干反应，并将其与使用常见高通掩蔽技术获得的反应进行比较。使用这三种掩蔽方法时，在衍生频段中心频率小于或等于1600Hz时均可检测到一个主要的晚期波Wa，该波是耳蜗顶部区域兴奋的典型表现。当在恒定刺激水平下降低中心频率时，该波的潜伏期会增加。对于衍生频段的恒定中心频率，当短声刺激水平以及与之平行的掩蔽水平降低时，波Wa的潜伏期会增加。在所有三种掩蔽方法中，均可在听力阈值附近发现波Wa。如果对陷波频率范围上下的频率区域进行完全掩蔽，则带陷噪声掩蔽方法具有主要优势。会发生直接的频率特异性刺激，无需从第二个反应中减去一个反应。这减少了研究时间和测量设备所需的存储容量。带陷噪声掩蔽方法的优势和适用性必须在患有不同频率依赖性听力损失的患者中重新检查。
