iPhone 5 ear speaker not working - only hear when using speaker phone

My ear peice speaker has stopped working. I can hear faint sounds through the ear piece but it is SO quiet. My phone only works when on speaker phone or when using ear buds. Can someone please help? I have checked a forum and they say that this may be due to the fact that he iPhone is sending audio to the headphone jack. To fix this they said to plug in a pair of head phones then unplug them - this should fix the problem. I have been trying this all morning and it is not working.

iPhone software is up to date. Come to think of it - updated it a few days ago, and that's when the speaker stopped working. Related? Or fluke?

Help!