Problems With Voice Memos

I cannot listen to my voice memos from my iphone. I originally wanted to transfer them to an external hard drive. When they first synced to itunes they were ok. Then I attempted to drag and drop them to my external hard drive and now they are like this -

Does anyone why know this is? I cannot listen to them on itunes now. They are still on my iphone. I have tried resyncing but it doesnt work. I really need these memos for uni.

Supriya