As to what I was referring to, yes, it's the copper lead that comes out of the faucet. You can take out the o-rings and buy new ones (for a few pennies) just to be sure that's not the problem. If the copper lead is 'kinked', any attempt to 'fix' it may actually ruin it.
And yes, if the flexible hose is kinked too much, you can get the whistling sound too. Get a loooooonger hose so it shapes into more of an 'S' than an 'L'. My best to ya and hope this helps.