iPhone 5 (6.0.1) Handset Volume Too Low

I've searched around the forums for this issue, and there seems to be a lot of similar issues but no real answers yet. I was hoping we could consolidate the threads and focus on the specific volume issue where the calling volume while in handset mode is too low to carry on a phone call. This issue started a few days ago and I have yet to fix it.

What I have tried:

1) Reset All Settings (General --> Reset)

2) Erase All Content and Settings (General --> Reset): This wipes the phone to factory settings

3) Disabling Siri (General --> Siri)

4) Increasing volume of phone and media player to max

If anyone else has experienced this problem, I would appreciate your input and if you have tried anything else/experiencing something else.

I'm starting to think this is a hardware defect that will warrant a recall, and I think we all want to avoid that hassle.