The mic makes noise to other players on the xbox party, game, etc..... I only hear it in the turtle beach when the volume is full.
It is not the talkback cable because I am using the one from my X31 and it works just fine!
Remember I do not hear it other people do. I used these about two months ago and they worked fine.
My X4s started doing weird things too. Sometimes it will make a constant noise like you're saying, but I can't hear it. I've asked my friends and they said it's a very faint noise, and it only does it when the mic is muted! It also seems like it echoes when I have the volume all the way up. I haven't noticed these issues since I switched to a different controller though, you should try that.