Harrison R V, Aran J M, Erre J P
J Acoust Soc Am. 1981 May;69(5):1374-85. doi: 10.1121/1.385819.
Measures of cochlear selectivity can be obtained from compound responses using tone-on-tone masking procedures [Dallos and Cheatham, J. Acoust. Soc. Am. 59, 591--597 (1976)]. For the normal guinea pig, cochlear fiber tuning is sharper by a factor of 1.8 than AP tuning curves using simultaneous masking (threshold criterion = 25% N1 amplitude reduction). Anesthesia does not appear to affect AP tuning. In pathological cochleas, AP tuning is broadened by a factor of 2--3, and differences between forward and simultaneous masking curves are reduced. Tuning changes can sometimes occur without threshold elevation. AP tuning curves were obtained from humans during transtympanic electrocochleography. For subjects with near normal thresholds, Q10dB values (simultaneous masking) are approximately 2.3 at 2 kHz, 3.6 at 4 kHz, and 4.7 at 8 kHz. Using the relationship between cochlear fiber tuning and AP tuning in the guinea pig, estimates of human cochlear fiber tuning are 4.2 at 2 kHz, 6.5 at 4 kHz, and 8.5 at 8 kHz. Patients with threshold elevations of more than 30 dB resulting from cochlear deafness have AP tuning curves less sharply tuned by a factor of 2--3.
使用纯音掩蔽程序，可以从复合反应中获得耳蜗选择性的测量结果[达洛斯和切瑟姆，《美国声学学会杂志》59, 591 - 597(1976)]。对于正常豚鼠，耳蜗纤维调谐比使用同时掩蔽的动作电位调谐曲线尖锐1.8倍(阈值标准 = 动作电位N1振幅降低25%)。麻醉似乎不影响动作电位调谐。在病理性耳蜗中，动作电位调谐拓宽2 - 3倍，前向掩蔽曲线和同时掩蔽曲线之间的差异减小。调谐变化有时在阈值未升高的情况下发生。在经鼓膜电耳蜗图检查期间从人类获取动作电位调谐曲线。对于阈值接近正常的受试者，2 kHz时的Q10dB值(同时掩蔽)约为2.3，4 kHz时为3.6，8 kHz时为4.7。利用豚鼠耳蜗纤维调谐与动作电位调谐之间的关系，估计人类耳蜗纤维调谐在2 kHz时为4.2，4 kHz时为6.5，8 kHz时为8.5。因耳蜗性聋导致阈值升高超过30 dB的患者，其动作电位调谐曲线的尖锐度降低2 - 3倍。
