Why can't people hear me when I call or take a call from my HTC M8 one?

[AC Question]

Friends can't seem to make out what I am saying on the phone as if I am talking in a different language has been going now for a week or so? Can't find anything in settings and to be honest haven't a clue what I am looking for.
The sound is muffled apparently, but I can hear them crystal clear...

 

[IAmSixNine]

I would reccoment getting a wired headset with mic and testing that way. If it works well then you know its a microphone issue. If it still sounds bad then its a board issue.