RESPONSES OF FIBERS IN CATS AUDITORY-NERVE TO CUBIC DIFFERENCE TONE
RESPONSES OF FIBERS IN CATS AUDITORY-NERVE TO CUBIC DIFFERENCE TONE
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DOI：
10.1121/1.382042
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发表时间：
1978-01-01
影响因子：
2.4
通讯作者：
RHODE, WS
中科院分区：
文献类型：
--
作者：
BUUNEN, TJF;RHODE, WS
用不同频率的单音和双音信号记录了猫S听神经的单纤维放电。单音频率从S纤维的最佳频率到此值的1.7倍左右呈阶梯式变化。双音信号的一个分量以完全相同的方式变化，而另一个分量的频率以这样一种方式增加，即在听觉系统内产生的立方差音(CDT，2f1-f2)的频率在光纤S最佳频率处保持恒定。收集了两种信号在放电率和周期直方图方面的反应。对单音和双音反应的尖峰率的差异可归因于CDT，并可用于估计CDT水平作为信号电平和频率的函数。在10 kHz以上的频率下，CDT水平相对于初级频率比较低的频率低约15dB值，并且随着刺激水平的增加，CDT水平略有下降。对频率低于4 kHz的CDT反应的周期直方图使估计CDT相位作为频率和2个产生音调的水平的函数成为可能。声调的强度对CDT相位没有影响。如果CDT的频率高于2.5 kHz，则变化的频率间隔会导致CDT相位发生数百度的偏移。对于较低的频率，位移较小，并且在不同的制剂之间差异很大。对于不同频率的声调和CDT，从周期直方图估计的相位以相同的方式变化。显然，CDT必须受到与由声调产生的耳蜗行波相同的延迟或相移的影响。
Recordings were made of discharges in single fibers of the cat''s auditory nerve using single-tone and 2-tone signals of varying frequency. The frequency of the single tone was varied stepwise from the fiber''s best frequency to about 1.7 times this value. One component of the 2-tone signal was varied in exactly the same manner while the frequency of the other was increased in such a way that the frequency of the cubic difference tone (CDT, 2f1-f2) generated within the auditory system was kept constant at the fiber''s best frequency. Responses in terms of discharge rate and period histograms were collected for both signals. The difference in spike rate between the response to the single tone and to the 2 tones could be ascribed to the CDT and was used to estimate the CDT level as a function of the signal level and frequency. The CDT level relative to that of the primaries was about 15 dB smaller for frequencies beyond 10 kHz than for lower frequencies, and slightly decreasing for an increasing stimulus level. Period histograms of responses to CDT of frequencies below 4 kHz made it possible to estimate CDT phase as a function of the frequencies and the level of the 2 generating tones. The intensity of the tones had no effect on the CDT phase. The varying frequency separation produced shifts in the CDT phase of several hundred degrees if its frequency was above 2.5 kHz. For lower frequencies the shifts were smaller and varied considerably between different preparations. The phase estimated from period histograms for acoustic tones and for CDT of varying frequency changed in an identical manner. Apparently the CDT must be subject to the same delays or phase shifts as the traveling wave in the cochlea produced by an acoustic tone.