Chosen Solution
I have an IPhone 5S, I tried calling someone today but i could not hear their voice, however they could hear mine. When i put my phone on speaker then i can just about hear their voice.
has the screen been previously replaced? if so it sounds like the earpiece speaker was not correctly reinstalled. If not, is the little earpiece speaker grille full of crud? you can’t hear through crud, pick that mess out with a toothpick CAREFULLY if still no solution, I’d suspect the front camera/proximity flex has failed, the earpiece speaker itself rarely fails unless you got water in it.
