If you can't get all of your voice memos off of your iPhone then you might want to try a following technique. You can see them in a playlist called voice memos on your iPhone, but they won't transfer when you sync.
How to Sync a Voice Memos playlist to an iPhone:
- Connect that iPhone to your computer.
- In iTunes, select iPhone in a sidebar.
- Select a Music tab.
- Select “Include voice memos” checkbox and then click "Apply".