My PC ain't noisy, but it certainly isn't "silent" either. There's a slight hum at all times, but it's not noticeable compared to... say, my PS4 which has a much more noticeable sound when it ramps up.
My PC also just doesn't really seem to get louder than it is when it's idle. I dunno.
I have two noctua static force fans or whatever they're called ("Noctua NF-F12 PWM, Premium Quiet Fan") hooked up to an all-in-one water CPU cooler with a lot of other case fans pushing and pulling air through my case at a fairly low speed. Either my video card doesn't get really loud during load(EVGA GTX1080 FTW), or I just never notice it. I want to move to a custom water loop someday, but I just don't really know where to buy all that stuff and I need to educate myself properly on it. I want to get around to delidding my 8700K first.
The only time I really notice my PC make a loud noise is when I'm ripping a DVD or Bluray with MakeMKV.