I live in an apartment and there is a low frequency noise coming from the floor of my bedroom. It is coming from the ceiling fan in the apartment below. The sound is very low, but after listening for a while it becomes painful to my ears. Surprisingly the people living below don't hear anything (or perhaps it gets masked by the normal sound of the fan).
I also think its impact noise, like the sound travels from the fan into the ceiling and then my room, and is not coming through air.
My bedroom should be around 12x12 feet. I have observed that the noise is higher in one corner and also in the center of the room. From what i have read about this topic i think these are called standing waves (not sure).
I used a stethoscope to listen to the floor and the vibration is higher in the center and decreases as i move away. Its almost negligible towards the end of the room. There are no vibrations in the walls. And nothing outside the room (air or floor).
Is there any way to block or absorb this sound? Will placing some sound absorbing material on the floor help? Or any other ideas?
I will talk to my neighbors, but seeing that they aren't facing the problem it may take some time to get it fixed.