Our parish’s new sound system includes those wireless microphones that fit over the speaker’s ear.
Our departing associate pastor gave them a thumbs-down. But he also moves his head side-to-side quite a bit while speaking, and doesn’t always give a consistent level of intelligibility to homilies or prayers.
One person on the committee was concerned a few months ago. This style is used by popular singers, and maybe it has too much association with secular life.
On the other hand, today’s concert singers use them because they are the best options for today’s multimedia pop presentations that employ singing, dance, and significant movement.
Sit in the purple chair. Do you care if Madonna and Father Pastor have the same head gear? Or does quality trump that consideration?
Catholic Sensibility 
I refuse to wear them. They don’t stay put, look terrible, and get in the way. I call them “Britney Spears”. If I am visiting a parish were there is no choice, I use them. For some priests with soft voices or a foreign accent, however, I realize that it may be the only option for some.
Our pastor got his first, called it Britney as well, loves it. We have two east Indian vicars who use them as well for accent issues.
I hate those things!