“Then a ringing silence, in which could be heard an apparent rain of small objects, striking walls and flagstones.”
The reason I choose this passage was it brought to mind an old field recording I'd recently used in the background of the first track on AND. It captured rain on a tin roof and seemed like it would suit.
The tinnitus-like ringing comes from Absynth, as does the low note. Both are treated with a lot of reverb, some delay, as well as compression.