Could definitely be a 3rd party app or setting conflicting with the configuration/setup and causing this so I would recommend doing a backup and then doing a factory reset with the auto restore disabled to avoid "reloading" the problem if this is the case....
If after a factory reset you still can't hear the other party, then you know it is a physical problem with the earpiece speaker.... .
We know how important it is for you to be able to hear callers while on phone calls. We'll get to the bottom of this. How long have you been having this issue? What zip code are you located in?
I VERY often have this problem. Especially when T-Mobile users call me. I also often have this problem when I use Google voice to forward my calls to my Verizon Cell phone.
Due to the age of this thread, it will be locked in order to keep discussions current. If you have the same or a similar question/issue we invite you to start a new thread on the topic.