I didn’t know how much of a treat I was in for today when I went to school. A guest speaker from a native tribe in Quebec came, and the last 10 minutes or so he played some beautiful songs.
He had three instruments, all wood, all end-blown. One was obviously a whistle, I saw the window and blade and it came to a stubby beak. The other two I couldnt figure out, they were both end blown but it did not come to a tapered end and I could not see a window. Could a blade be internal? Could his embouchure have split the air on the tube end?
Or maybe the blade was ON the end - like a South American Quena or some such. There the embouchure has to do what the windway in a whistle does… rather challenging at first based on my feeble attempts and near complete failure to even get a sound from an Andean native instrument when I had the chance…And I used to play transverse (concert) flutes, too.
Maybe something like this (upper left corner), just a soundblade cut into the end. If it was the same color as the rest of the barrel, it would probably be unnoticeable.
It also depends on the type of Native American flute your’e playing (sorry, offshoot to Native Americna flutes) They as diverse as many other instruments.
There are simple 5 hole that really sound very beautiful as any other, but really require no special skill other than breath control and moving your fingers, no second octave to speak of usually.
There are 6 hole, then 6 hole with a thumb hole, 5 hole with thumb hole, 3 hole, 4 hole… those are the ones I’ve played anyway. I’m sure there are probably more.
Anyway… just different skills / practice to play any one of them. I found the 6 hole w/ thumb hole to be the most difficult to play… it did not respond like ANY other wind instrument I have ever played. Forget any sort of normal pattern such as a recorder or anything. Way odd… to me. All the other I could pretty much ‘pick up and play’ after a bit.
Quenas? Forget it! I thought my lungs were going to explode and my head fall off my shoulders by the time I figured out the embochure, and I still sucked. But boy the guy who had it sure could make it sing!
True enough..i was thinking of the kind you find most often when you type “native american flute” into a search engine..you know, the 5 or 6 hole type, with 2 chambers, and a “bird” to direct the wind from the first chamber into the 2nd chamber… I think we both agree that these kind require only breath and finger control, and no special embouchure or anything.
I have two quenas, and sometimes, I can really make them sound good..and sometimes, I just sound like i’m blowing air
)
I thought my lungs were going to explode and my head fall off my shoulders by the time I figured out the embochure, and I still sucked. 
But boy the guy who had it sure could make it sing!