Falsetto notes are not necessarily above the range of your normal singing voice, they are just produced a different way--in my case, my falsetto range doesn't exceed my full voice range--Yodelling uses both voices, with a voice break between the two, which is to say, you are moving from falsetto voice to full voice, or full voice to falsetto while voicing a note--there is either a jump up (from full to falsetto) or down(from falsetto to full) but that jump is often only a fifth or sixth--occasionally, it can be as small as a minor third. In Hawaiian singing, often the break leads to or from a pitch that is out of tune for the scale that is being sung, which makes for an even funkier sound--

It occurs to me that it is possible to move from falsetto to full voice without changing pitch--the break wouldn't be as dramatic as when changing pitch though. I have a cold right now, and I don't have a lot of control, or I'd try it.