为使短声诱发的 ABR 阈值更接近实际反应阈,作者研究了短声极性对 ABR 阈值的影响。用宽100微秒的方波输入 TDH 49耳机产生疏相和密相的短声,刺激重复率为48次/秒。由不同极性短声的主观听阈至10dB(SL)之间。每2dB 一档刺激,以无规律变化的短声极性和强度顺序给声。测试10名(3男,7女),主观听力正常者,在自然睡眠状态下的 ABR 阈值。记录电极放置颅顶,参考电极放置颈部第七颈椎处,放大器滤波范围100～3000Hz(12dB/oct),扫描时间15ms,叠加次数10000,用Elberling 等提出的 ABR 反应信噪比 Fsp 值估计法,客观判断 ABR 阈值。结果发现疏相短声的主观阈值为32.7dB In order to make the short-sound-induced ABR threshold closer to the actual response threshold, the authors investigated the effect of short-sound polarity on the ABR threshold. Square wave with a width of 100 microseconds input TDH 49 headphone to generate phase and phase short beats, stimulation repetition rate of 48 beats / second. The subjective hearing threshold of short-sounding by different polarities is between 10dB (SL). Each 2dB stimulus, with irregular changes in the short-sound polarity and intensity order to sound. Ten (3 males and 7 females) subjects with normal subjective hearing were tested for ABR thresholds under natural sleep conditions. The recording electrode is placed on the cranial top. The reference electrode is placed on the neck of the seventh cervical vertebra. The filter range of the amplifier is 100 ~ 3000Hz (12dB / oct), the scanning time is 15ms and the superposition frequency is 10000. The ABR response signal- , Judge ABR threshold objectively. The result shows that the subjective threshold of sparse phase shortness is 32.7dB