Gerhardt H C
Science. 1978 Mar 10;199(4333):1089-91. doi: 10.1126/science.628833.
Male Hyla cinerea produce two distinctive calls. Acoustically intermediate calls are rare. Females discriminate between synthetic intermediates that differ by one cycle of amplitude modulation (50 per second). Processing appears to be continuous. The tree frog's auditory system thus provides a wide margin for the discrimination of its two principal signals.
雄性灰树蛙会发出两种独特的叫声。声学上介于两者之间的叫声很罕见。雌性能够区分相差一个调幅周期（每秒50次）的合成中间叫声。处理过程似乎是连续的。因此，这种树蛙的听觉系统为区分其两种主要信号提供了很大的余地。
