Indeed, some toothed whales and bats emit sound pulses around 200,000 hertz and listen for the reflections.

事实上，一些齿鲸和蝙蝠会发出 20 万赫兹左右的声脉冲收听反射声。

You send out a sound pulse and then once it bounces off an obstacle, you can tell how far the obstacle is.

你发出一个脉冲音波，一旦它被障碍物反弹回来，你就能知道距离障碍物有多远。