PSU making loud noise

[dadiablo]

So I have built my own computer and love it so far!
I have had it since May 2012 and it has suit my needs.

Recently I am concerned with what is happening to my computer. It started happening 2 days ago and I try not to use it often after it happening. Today I just cleaned my computer of dust, but it still happens. Here is the problem I am having, I will link it.

Youtube Videos

The first video is when I turn it on and it runs normal. The second video is when it starts to making a loud fan noise. It is titled of what is happening.
The PSU is a Corsair CX 500. I bought this unit from Amazon on April 25th 2012.

So I think I narrowed it down to the PSU heavily blowing. The loud noises happen after using my computer for 10-20 minutes. I have not experienced any glitches or freezes on my desktop. It runs fine. Has anybody had this problem? What are my options?

 

[Dark Lord of Tech]

Doesn't sound that bad.

 

[dadiablo]

Doesn't sound that bad.

Really? I just never heard it do that. I was scared to leave my computer on after hearing it.

Recently it has gotten cold in the Bay Area, California. It goes to low 30F at night. I am upstairs while my desktop sits on my desk. I think the cold could be one of the things making the PSU sound harsh to warm up, but that is my opinion. I took a bit extra measures by changing the power cord and surge protector. I had used it for an hour with light usage and it runs fine. I hope not to encounter more problems.