Call audio issues with my 1520

[Mongotoo]

I'm experiencing some call audio problems when I make or receive a phone call. I have to use the "speaker" option in order for the caller on the other end to hear me. If I use it normally and hold it up to my ear, the caller can't hear me unless I scream at them. Anyone else have this issue and is there a resolution to this?
I am using Windows 8.1 (OS ver. 8.10.12397.895)