I have stayed at Pop many times since the room renovation. I would occasionally hear a muffled toilet flush, but that’s it, even on the ground floor. EXCEPT the one trip where I got a room with a connecting door. I could hear everything that happened in the neighboring room, even if they weren’t being especially noisy. So if you get a connecting room, you should ask to be moved.
I second the white noise app recommendation. I use one all the time at home due to barking dogs in the neighborhood, and I use it when traveling. Get one with noises you can customize (mine lets me mix up to four different sounds) so you can find one that works for you.