If you've got a faucet at home that makes a lot of noise then you know how annoying it can be. I used to hate washing dishes because I couldn't even carry on a conversation with my wife over the shrill whine that erupted from the kitchen faucet every time the water ran. But I fixed it! It seems that the primary source of noise in a faucet is the aerator, numbered "1" in the diagram below.
First, unscrew the aerator and check it for mineral deposits. Removing debris will often eliminate a great deal of noise. Try running the faucet without the aerator to hear if the noise goes away. If not, then your problem is something else. Screw the newly-cleaned aerator back on and check if the noise returns. If so, buy a new aerator from Home Depot for 50 cents.