You are on the right track—it is actually the echo of all the leaves as a whole that matters.

你找对思路了——真正重要的是所有树叶整体的回声。

youdao

We shouted in the valley, and in an instant, the echo came from the hillside with great distinctness.

我们在山谷里大喊，不一会儿，回声就清晰地从山坡上传来。

youdao

By hanging panels of sound absorbing felt on the walls, Sabine reduced the echo enough to make the hall usable.

通过在墙上悬挂吸音板，Sabine 减少了足够的回声，使大厅可用。

youdao

"We made some goofs that were kind of interesting,". "We didn't make the hallway wide enough to get a piano down, we forgot to put AC outlets in one of the studios, and we completely forgot the echo chambers, so we had to put them under the parking lot.

VOA: standard.2009.08.14

At this point it's wonderful: Samson begins to echo Milton from the invocation that we've been looking at, the invocation to Book Three of Paradise Lost.

这里很奇妙：,参孙开始附和弥尔顿的祈求,我们刚才看到的失乐园第三卷中的祈求。

耶鲁公开课 - 弥尔顿课程节选

The Virgilian echo gives this passage in Milton an unmistakable pathos and an undeniable beauty.

这个维吉尔式的共鸣在弥尔顿而言,传递了一种一目了然的悲怆和不可否认的绝美。

耶鲁公开课 - 弥尔顿课程节选

Indeed, Sprint appears to be dedicating a surprising amount of support to the Echo.

FORBES: Sprint, Chasing Innovation, Readies Phone That Unfolds Into Tablet

The upshot is that the Echo can feel more computer-like than a regular smartphone.

FORBES: Sprint, Chasing Innovation, Readies Phone That Unfolds Into Tablet

For surely woods, trees, and rocks produce the echo that man desires to hear.

NPR: Beethoven's Symphony No. 6 in F Major, Op. 68