Is there any sound worse than the one created by feedback from a Portable PA System? You know the sound, a ringing noise or terrible squealing or screeching. It’s something that you very commonly hear over Portable Public Address Systems, but it’s one that can very much be avoided with just a little bit of preparation and placement of the PA System components. Before we get to these steps, you should know that if you are the speaker and you hear that awful screech, placing your hand over the mic will not dampen the sound, and will in fact just make it worse.