Sorry to hear (bad choice of wording..sorry ) about the sound issues. In this type of situation I would bite the bullet and flash it back to factory. If after doing that the earpiece speaker still didn't work, I would have to assume that the speaker probably went bad and take a trip to my local VZW store and see if it could be replaced. Of course you could also call into VZW support and see if they will issue you a replacement.
However, before doing all of that you may want to boot it into safemode. To do this, power your phone down and once powered down turn it back on. When you see the Moto dual core logo, press and hold both the volume up and volume down buttons until you see "Safemode" in the lower left hand corner. If doing this enables your speaker to function, then it is more than likely a 3rd party application that is causing the problem. From here you can try uninstalling any and all 3rd party applications that have been installed or just flash it back to factory by doing a wipe.