Reale R A, Geisler C D
J Acoust Soc Am. 1980 Mar;67(3):891-902. doi: 10.1121/1.383969.
Responses to two harmonically related tones, approximating the lowest formants of nine American English vowels, were recorded from single auditory-nerve fibers. Data were compiled as period histograms for tones presented singly and in combination using the fundamental frequency of the two-tone complex as the time base. The amplitudes of the primary frequency components present in a histogram were estimated by least-squares fitting a half-wave rectified sum of the stimulating sinusoids plus a constant. Nonlinear interactions resulted for most two-tone stimuli: one tone dominated the response. When one tone was equal to best frequency, that tone always controlled discharge timing, usually suppressing the response to the second tone. Complicated interactions took place when the stimulating frequencies bracketed best frequency. The tone nearest best frequency was most effective near threshold, while higher stimulus levels usually favored the low-frequency tone. Nevertheless, the suppression mechanisms appear to provide an effective spatial separation in the cochlea for the response components to each vowel approximation. Fourier analysis of the period histograms yielded qualitatively similar results.
从单根听神经纤维记录了对两个谐波相关音调的反应，这两个音调近似于九个美国英语元音的最低共振峰。数据被汇编成单音和组合音的周期直方图，使用双音复合体的基频作为时间基准。通过对刺激正弦波的半波整流和加上一个常数进行最小二乘拟合，估计直方图中存在的主要频率成分的幅度。大多数双音刺激都会产生非线性相互作用：一个音调主导反应。当一个音调等于最佳频率时，该音调总是控制放电时间，通常会抑制对第二个音调的反应。当刺激频率包围最佳频率时，会发生复杂的相互作用。最接近最佳频率的音调在阈值附近最有效，而较高的刺激水平通常有利于低频音调。然而，抑制机制似乎在耳蜗中为每个元音近似的反应成分提供了有效的空间分离。周期直方图的傅里叶分析产生了定性相似的结果。
