When I am in a call, the sound from the earpiece is very quiet. Its at the point where I can barely hear what people are saying, and I always have to request them to repeat themselves.

Obviously I know how to turn the volume up during a call, and I keep it at full volume all the time. I can hear fine with headphones or my bluetooth headset, but the problem occurs when I use only the built in earpiece in the phone.

Is there some sort of fix or app for this? Or is it a defective phone? Thanks for the help