Ursprünglicher Beitrag von: Brittain Porter ,
Before you trying repairing anything, take a look at the earpiece speaker at the top of the screen. Sometimes oil and dead skin can build up a small layer covering up the speaker grate. Try taking a Q-Tip [preferably dipped in an strong alcohol solution] and cleaning the grate. Try not to press too hard, but that might help. If not, then I'd follow Adam's advise and replace the speaker.