4-5 times per week we hear this through the ceiling:
The fidelity on that recording isn’t great, but you should be able to hear how it has very-fast-oscillation pulses of some sort, and then superimposed on that, it speeds up and slows down as if it were encountering resistance.
I’ve heard that general kind of sound from…
• Electrical drills and electrical screwdrivers, when set to slow speed. (But if she were constructing bookshelves or drilling holes in the wall, one would expect her to be at it for a couple hours on one day then BE DONE with it instead of 30 secs +/-, no more than once a day, every few days in perpetuity… ?)
• Electrical can openers, of the sort where you’d lift the bar, insert the can which gets pinched when you lower the bar, and it spins the can around… but those things don’t take 30 seconds to open a can of ANYTHING. And it sounds a bit too industrial for that, actually.
• Home dental tools, electric toothbrushes, water piks, etc. (But not this loud, not this industrial. Those generally sound more treble-pitched and raspier, chatterier, less ‘motorish’. Besides, it’s coming from the opposite end of the apartment from bathroom and kitchen; there would be no water supply close to where she runs this thing).
• My annoyed girlfriend says: “vibrator”. Naah. Those don’t sound like drills either, we aren’t under the gal’s bed (unless she sleeps in the entrance foyer of the apartment), the sounds are unaccompanied by gasps moans or etc.
•Floor polisher. Except it doesn’t travel around the apartment, there’s none of those gruff grumbly sounds you’d get when you buff up to the floorboard, it doesn’t last long enough, and there’s no sound of things rolling overhead. Whatever this is, it’s stationary.
•VHS tape rewinder. Not quite industrial enough EITHER (those are usually lower in pitch and not as loud), and who the heck still has VHS tape rewinding machines?
