Joermann G
Zoological Institute, University of Bonn, F.R.G.
Hear Res. 1988 Sep 15;35(2-3):191-9. doi: 10.1016/0378-5955(88)90117-7.
Single-unit recordings from neurons in the torus semicircularis of Rana ridibunda were analyzed to determine the degree to which these neurons can detect acoustic stimuli superimposed on continuous, broad-band noise. In the first series of trials the stimuli were tone pulses 25 ms long, 5 dB above threshold, and at the characteristic frequency of the neuron. Most cells responded to the stimulus for signal-to-noise ratios of 25-35 dB (tone intensity minus spectral noise density); the lowest values were about 20 dB. The same signal-to-noise ratio was obtained with tones 20 dB above threshold. In the second series, conspecific mating calls at an intensity of 60 dB were tested. Here the signal-to-noise ratio (peak intensity of the call minus noise level) was usually 45-60 dB, in 5 of 27 cells it was 40 dB. Increasing the call intensity to 80 dB raised the SNR by an average of 6 dB. Noise-tolerant units more commonly gave synchronous responses to the pulse groups in the call, and are better tuned to its frequency range, than noise-sensitive units.
对泽蛙半规管神经元进行单单位记录分析，以确定这些神经元检测叠加在连续宽带噪声上的声学刺激的程度。在第一系列试验中，刺激为时长25毫秒、比阈值高5分贝且处于神经元特征频率的音调脉冲。大多数细胞对信噪比为25 - 35分贝（音调强度减去频谱噪声密度）的刺激有反应；最低值约为20分贝。对于比阈值高20分贝的音调，也获得了相同的信噪比。在第二系列试验中，测试了强度为60分贝的同种交配叫声。此处信噪比（叫声峰值强度减去噪声水平）通常为45 - 60分贝，27个细胞中有5个细胞的信噪比为40分贝。将叫声强度提高到80分贝，信噪比平均提高6分贝。与噪声敏感单位相比，耐噪声单位对叫声中的脉冲组更常产生同步反应，并且对其频率范围的调谐更好。
