Aha. The occasional pulses of low-frequency noise are almost certainly coming from the building, somehow. Perhaps something to do with the heat, as the temperature has gone down in the last couple of days. Very eerie sound, but good to know that it's something local as opposed to odd in the city at large. Possibly some steam mechanism -- no idea how those things work here. When, before this last visit, I read a recent Russian novel that used the community's shared heating network as a plot point, I thought it was the author's invention.
Relatedly: cheap pasta over a low-power hob is a tricky skill, but one that must be mastered for digestive health. Raw wheat isn't generally what the body hopes to gain from the meal.