It's really hard to tell what the issue is. I uploaded this as a test and response using Adrenaline to record audio: Radeon ReLive No Audio post - response - YouTube
As for the voice recording, make sure to set the Audio capture device specifically what Windows has set up. I circled mine, but I'm just highlighting it on where to look.
Also make sure you have the following field set to disabled unless you want a separate audio track (in .m4a format). A friend had this selected so his final video recording had no audio as it was not embedded in the mp4 file! The actual .m4a file was lost in the folder of hundreds of other videos.
So I watched your video response and I checked all my settings in ReLive and I'm using the same setttings as you except of the Max Recording Bitrate, I'm using 50 Mbps. But still, it won't record any sound :c something I noticed later, the sound in my clips which i recorded earlier is kind of streched. At the beginning its good but at the end the sound is 10-20 Sec delayed :/