《太平广记·卷四百六十五·水族二》
如果没有雷声，打鱼的人就在雷穴的洞口安上好几面鼓一起敲打起来，鱼也能流出来，捕到的鱼只有打雷时的一半。
非雷声，渔子聚鼓击于穴口，鱼亦辄出，所获半于雷时。
If there was no thunder, fishermen would fix several drums over the entrance to the thunder-hole and beat them together. Fish would still come out, even though the catch would be half that obtained during the thunder.