Why can't anyone hear me when I call or get called?

[Windows Central Question]

Not sure if this problem has been solved as I can't find a solution anywhere. I have a Lumia 830 and about a month ago when I call someone or someone calls me I can hear them fine but they can't hear anything unless I put in speaker where communication is fine. At that time I rebooted and reset my phone to same problem although on voice recording and Cortona the microphone works. I left it just in case somehow overtime it went back to being okay. But still have the problem, Is it the software or maybe the microphone is busted or if is in headphone mode? Any help or suggestions would be appreciated. Thanks...