One of my colleagues, who must give many presentations at our school, has a hearing aid. The problem we have run into is that when she is close to a wireless microphone, her hearing aid gives out a loud chirping noise. Has anyone else had this problem? Is this an interference issue? Could I fix this by switching to a wired mic instead? I'm trying to be discreet about this so as to not hurt her feelings. Any feedback would be appreciated. Thank you.