First, they absorb sound since thick branches and leaves are great at absorbing high frequency noise.

首先，它们可以吸收声音，因为粗壮的树枝和树叶可以很好地吸收高频噪音。

Now, that means that if you're only able to hear the low end because of some high frequency noise that's in the environment, we can still communicate as human beings.

那意味着，如果你只能听到低频，比如在有高频噪音的环境中，我们人类仍然可以沟通。