He invites us to hear the sweep of the scythe in those s sounds themselves, I think, and maybe even to hear the workers huff and puff, his rhythmic exhalation in the w's, which alternate and interact with those s's.

他让我们倾听镰刀扫过的声音,我觉得应该是这些s的发音上,也可能是听着劳动者的喘息声，他的有节奏的w似的发声，跟s音交替着互动。

耶鲁公开课 - 现代诗歌课程节选