Question I hear a wierd whoom sound from my system

[Alekan32]

I hear a wierd whoom sound from my system not that loud.I also can feel a little vibrate from that sound on the case.I thought it was COIL wine or something with the fans but idk what it i also been trying to record it for you to hear it but my mic cannot catch the that sound for some reason.Then i thiught it could be the hdd but idk or the psu??? IDK please help.The best i can discribe it is a kinda loud whooom it kinda goes like and alarm whoom whoom whoom but a fat noice you know what i mean thats why i thought it was a fan or something BUT IDK.

 

[Alekan32]

Also the performance is ok like its just the noice but some times its getting louder and annoying.And some times the noice just stops???And then again I NEED HELP!!!!