Hubbard A E, Mountain D C, Geisler C D
J Acoust Soc Am. 1979 Aug;66(2):415-30. doi: 10.1121/1.383093.
Cochlear microphonic (CM) in response to low-frequency tonal stimuli, measured as a function of sound-pressure level (SPL) in scala media of the guinea pig cochlea, was averaged and Fourier analyzed. The slope of the amplitude of the Nth CM harmonic versus sound intensity in log-log coordinates was approximately N (1 less than or equal to N less than or equal to 5) in the first three cochlear turns, but notable variations on such a slope rule were found to apply to CM in turn I. CM harmonic phases plotted versus SPL were found to group into two distinctive categories expressly delimited by whether the order of the harmonic was even or odd. Some difference between CM recorded between scala media and scala tympani and recorded between scala media and the animal's neck could be attributed to neural contamination. We also found CM in its saturation region to have a hysteretic relation to the input sound pressure. At high sound levels, large, physiologically produced acoustic harmonics existed at the animal's eardrum. Our data support an asymmetrical, saturating, single-valued nonlinearity as a model for CM generation at low sound levels. At higher sound levels a different, more complex, hysteretic nonlinearity seems mandatory.
测量豚鼠耳蜗中阶声压级（SPL）函数下对低频音调刺激的耳蜗微音器电位（CM），进行平均并进行傅里叶分析。在前三个耳蜗转中，第N个CM谐波幅度在对数-对数坐标中相对于声强的斜率约为N（1≤N≤5），但发现该斜率规则在I转CM中有显著变化。绘制的CM谐波相位与SPL的关系分为两个不同类别，明确由谐波阶数是偶数还是奇数界定。在中阶和鼓阶之间记录的CM与在中阶和动物颈部之间记录的CM之间的一些差异可归因于神经污染。我们还发现CM在其饱和区域与输入声压具有滞后关系。在高声级时，动物鼓膜处存在大量生理产生的声学谐波。我们的数据支持不对称、饱和、单值非线性作为低声级CM产生的模型。在较高声级时，似乎需要不同的、更复杂的滞后非线性。
