See also this question:
I recently soaked my Moen shower head in vinegar for a day to fix a problem where the center jets which pulsate were not working. Inside is an impeller of some kind and I assumed it was not spinning properly because of hard water buildup or lime, etc. Soaking in vinegar did the trick, the center jets are working better than ever.
But... the shrieking began. I looked up the above question but since I just cleaned the shower head, the answer is not satisfying.
So, how do I stop the shrieking? Is it time to get a new shower head? Will a more expensive one avoid this problem better?