The fans should not be heard and only be heard if your system is using a lot of electricity.
When that happens the fans speed up, at least they do in my Power Station Unit.
If you can hear your fan revving up that's okay. But be warned, it shouldn't revv up enough so you hear it all the time.
If it doesn't quiet down to a whisper after an intense video pix load causes it to start screaming at you (because of the load on the PSu) even when you're not using a super duper video card on High and Ultra High settings, THEN, you haven't got an adequate power supply for your peripheral parts when you are gaming. Any one of the parts???
No, mostly the Video Card is really the electricity sucking v(amp)ire.
The v(amp)ire that puts a load on your PSU. It should only SCREAM when when the v(amp)ire starts feeding. Like the nice Halloween musical YouTubes you posted last will drink up lots of electricity! Your electricity!
If the fan is making noise enough to be heard all the time, you're likely sitting too close to the computer.
Or its a fan built for closed in systems that redirect the heat from a houses Furnace to get to places in corners to keep rooms warm that is difficult to put large heat duct in there, and in the case of a necromancers revived PSU (also known as a Refurbished unit) running in the standard running state; Well; you've likely got a BANSHEE riding on the blades of the fan for fun; because she knows it will die sooner than later.
She's riding it like a ride at the carnival free of charge a'waiting for the fan to stop.
If you are happy with the electric power supply system, it might be best to put a muffler on it. Or hook a heat pipe from it to the floor to warm your feet. Or get and replace it with a gamer's fan that is made to be faster and quieter with more fins.
We only want to hear your joyful agonizing sounds that you make when you're hearing the background sounds like a draugr sneaking up on you, your heart racing in your chest, and not hear tears flowing down your cheeks because the fan racing is interrupting your focus on the game instead to keep the PSU cool.
Maybe it's time you found a 1000 Watt PSU with a fan that's meant for the v(amp)ires kiss that your PC doesn't mind, until, the v(amp)ire kisses you a third time or uses you once more for food?
Super Duper Gaming Computers need a Power Supply with 1200 Watts. OR some v(amp)ires won't even bother to come around for a visit much less take big sips of electrical juice from your system.
You could always use some heater vents and assemble them so they go under your floor over to up under your beds mattress so when you retire to your wife's or Ghoulfriend's queen size coffin to get some sleep you'd find the PSU fan warmed it up for you. Succubus (known as Dream ghouls or dream girls) are not known to warm up anything and only arouse us when we're already asleep in our cozy warm bed covered in soft clean sheets and blankee's. I understand they like to mess the clean beds up. Jealous of us single Boils (boys) with money enough for a decent bed to sleep in? Maybe?
That is; unless you like it cold like Frank(enstein) so you don't feel overheated body parts while you've got your necks charging posts hooked up to the power station while you're laying on your morgue table getting all charged up for Halloween.