Here's what you'll want to do. In "Menu" mode (click menu button)
Go to "Mic Sense" and select "High"
Go to "Rec Mode" and select "MP3 192 kbps (Stereo)"
Go to "Low Cut Filter" and select "Off"
Go to "VCVA" and select "Off"
You can then save the scene.
All this can be found starting on page 11 of the manual.
For those who don't have the manual, I'll attach one here.
As for the singing, not much I can help with there. Although you're more than welcome to share that with us as well. Perhaps you can become the next Paranormal Idol!