They have very keenly developed echo location sonar sense associated with their brains that is a unique feature of toothed whales.

它们有与大脑相关的非常发达的回声定位声纳感觉，那是齿鲸独一无二的特点。

They just have the added benefit of echo location to operate in the dark.

他们只是有回声定位的额外好处，可以在黑暗中操作。