psu buzzing

Every now and then a buzzing sound comes from my PC and what I believe to be the PSU and what sounds like the fan. However by unplugging the computer and leaving it for a few minutes the sound is fixed which to me doesn't make sense for this to be the fan. The sound will then not come back for...

There is a really odd buzzing sound coming from my PSU that seems to heavily correspond to the load on power, which make sense I guess. However, this is very loud and concerning, as I'm not sure what's causing it. What makes this weirder, is that it only happens with certain games. (The only...