This happened to me and it did both ways. 1. I could hear, others could not hear me. 2.They could hear, but I could not hear them.
A lot of mics are not made very well man..I mean you can can buy those turtle beaches, but just regular mics need to be made better.
Sometimes you may find your mic will start working as mine did, but it usually indicates an internal failure and you need a new one. If you say others can hear you, but you can not hear them then you could turn the speakers on. You could hear them through your tv. This is what i did.
I wrote a hub about mics