I'm the vocalist in my band and sometimes it's hard to hear myself singing while the music is being played, and it bothers me because sometimes its hard to hear if im on key or not.

I noticed that many musicians have a "hearing aid" type mechinism in their ears (mostly the vocalists) and I am assuming thats how they hear themselves better.

Can you tell me what that is and if its what I think it is and perhaps any other info on it?

thanks

In-ear monitoring.

Yes...jazzfromhell is correct. It is difficult to get used to for many people though. The old style of monitoring is still quite common...glorified speakers facing all of the musicians often with a different mix than the mains.

Yeah, but if you're poor and you need to hear yourself you can just set up your PA or whatever you're using to amp yourself right behind you, usually works pretty well.