Dunia R, Narins P M
Department of Biology and Brain Research Institute, University of California, Los Angeles 90024.
J Acoust Soc Am. 1989 Apr;85(4):1630-8. doi: 10.1121/1.397951.
Sinusoidally amplitude-modulated (SAM) noise was monaurally presented to the neotropical frog, Eleutherodactylus coqui, while recording intracellularly from auditory-nerve fibers. Neuronal phase locking was measured to the SAM noise envelope in the form of a period histogram. The modulation depth was changed (in 10% steps) until the threshold modulation depth was determined. This was repeated for various modulation frequencies (20-1200 Hz) and different levels of SAM noise (34-64 dB/Hz). From these data, temporal modulation transfer functions (TMTFs) were produced and minimum integration time (MIT) for each auditory fiber was calculated. The median MIT was 0.42 ms (lower quartile 0.32, upper quartile 0.68 ms). A noise level-dependent effect was noted on the shape of the TMTF as well as the minimum integration time. The latter results may be explained as a loss in spectral resolution with increasing noise level, which is consistent with the correlation that was found between minimum integration time and bandwidth.
以正弦幅度调制（SAM）的噪声单耳呈现给新热带蛙类，即寇奎姬蛙，同时从听神经纤维进行细胞内记录。以周期直方图的形式测量神经元对SAM噪声包络的相位锁定。改变调制深度（以10%的步长），直到确定阈值调制深度。针对各种调制频率（20 - 1200赫兹）和不同水平的SAM噪声（34 - 64分贝/赫兹）重复此操作。根据这些数据，生成了时间调制传递函数（TMTF），并计算了每条听神经纤维的最小积分时间（MIT）。MIT的中位数为0.42毫秒（下四分位数为0.32，上四分位数为0.68毫秒）。注意到噪声水平对TMTF的形状以及最小积分时间有影响。后一个结果可以解释为随着噪声水平增加，频谱分辨率下降，这与在最小积分时间和带宽之间发现的相关性一致。
