Problems with fan noises can drive drive you crazy.  They are loud annoying but, absolutely necessary to keep your CPU and other components cool.  I had originally posted a fun do it yourself project but, was ask to take it down.  Well, I built the project and it worked fine but, cost 3 times more than just purchasing a Zalman Fanmate 2 from New Egg.  Do not waste your time shopping anywhere else because some online stores are charging $18 US.  New Egg is only charging $4 US but the shipping is about $4 too.  So for $8 dollars you can get a great fan controller that looks better and is more reliable than the DIY one.  Take my advice, purchase 3 or 5 because you will save in shipping and will find that you will have one when you need one.