It's just all one wall of sound.

这就是很单调的声音。

And it's a sort of slow-moving and really formidable, almost a sort of wall of sound, you could say.

这是一种缓慢移动且非常强大的声音，你可以说它几乎是一种音墙。

" The blare of traffic" , the blare, so as I said, like a wall of sound.

“交通的喧嚣”，喧嚣，就像我说的，就像一堵音墙。