Milton is narrating or representing the process by which they are silenced. They're rendered speechless or dumb, and the poem effects this process in order to give someone else an opportunity to speak.

弥尔顿在叙述或描绘这个,他们缄默的过程，他们都变得沉默或哑巴了，同时诗歌也影响了这个过程,为了使另外某个人有机会开口说话。

耶鲁公开课 - 弥尔顿课程节选

Wireless communication devices must be silenced.

无线通讯的设备必须是静音的。

麻省理工公开课 - 固态化学导论课程节选