Power Supply Faint Buzzing

[willreale7]

I turned on my computer and I heard a faint buzzing sound that I haven't heard before. I turned off my power supply and the noise went away. I'm not sure if this is something I should be worried about or not. It could also be that my ears never picked up on the noise until now...

 

[jankerson]

System specs including PSU make and model?