"if the playback was not to your liking, then the chances are that, as you sang, you were hearing your voice on the way IN to the recorder rather than on the way OUT"

Well... the first time you hear your voice from a recorder of any type, it's a bit of a shock! Wonder WHY some singers cup a hand over an ear? It's because the sound that you 'hear' in your head when you sing is very different from what the outside world 'hears'. By cupping the hand over the ear, some of the external 'sound' is reflected back and you can hear yourself more like what the world 'hears' you. (And if you don't like that...) It also allows some of us to 'find pitch', especially if singing ion a group, faster and more spot on, among other things.