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近年来常用于蜗后病变的测听技术有言语测听、声阻抗测听及脑干反应测听等。偏侧试验(lateralization test)是用上升、下降时间为10ms,时程为50ms的40dB SL的400赫纯音,测试受试者足以辨别出到达两耳的声信号的最小时间差(Δt)和声强差(Δi)。正常人能辨别先后相差50～150μs到达两耳的声信号(临床以500μs为Δt正常值上限),和能辨别两耳声强相差1～2 dB的声信号(临床以4dB为Δi的上限)。言语测听主要测试合成语句(synthetic sentence)清晰度(简作SSI),和合成语句与竞争信号比率(MCR)。竞争语句测听包括同侧竞争(ICM)和对侧竞争(CCM)。SSI-ICM的正常值为:MCR为+10/0 dB时识别100%,MCR为-10dB时识
In recent years, commonly used audiometry audiometry audiometry audiometry, acoustic impedance audiometry and brainstem response audiometry. The lateralization test was a 400 Hz pure tone of 40 dB SL with a rise and fall time of 10 ms and a time duration of 50 ms. The test subjects were able to discern a minimum time difference (Δt) and sound intensity of the acoustic signal reaching both ears Difference (Δi). Normal people can distinguish between the sound signal of 50 ~ 150μs reaching the two ears (the upper limit of normal value of Δt is 500μs in clinical practice), and the sound signal of 1 ~ 2 dB difference between the two ears can be distinguished (the upper limit of Δi is 4dB in clinical practice) . Speech audiometry mainly tests synthetic sentence sharpness (SSI), and synthetic sentence to competition signal ratio (MCR). Competitive statement audiometry includes ipsilateral competition (ICM) and contra-lateral competition (CCM). Normal values for SSI-ICM are: 100% when MCR is +10 / 0 dB, and -10 dB when MCR is -10dB