Hi and welcome to TSF
You say when you move the wire in a certain position you can hear others?And when you use normal tv speakers it works fine? Sounds like the wire is ripped inside, is it a little torn on the outside? I remember buying hi-def headphones and the wire was a bit ripped and when I put in a certain spot it worked, I exchanged. If it is the wire, I'd recommend exchanging it if possible, or just buy a new one.
Edit: When you say microphone, you mean headset?