Default Call audio only working in one earphone

I recently installed Temasek CM11 build, and have found that when i take a call while using earphones, it barely plays through one of the earphones, almost as if it is mono. But everything else is perfect sound games videos. I have tried searching for similar problems to see if a solution exists, but no luck yet, i cant see anything suggestive in phone settings itself either. Anyone have any idea what could be wrong?