This fellow is very good - hear he makes the rounds during festivals like the Willie Clancy Summer School. I think it was on a 78 of khene where you can hear a boat whistle off in the background...fascinating instruments.
Found a bit
about their construction:
How is the Khene made?
Khene is made from a special kind of bamboo, similar to reed, of 5 centimetres (cm) large and 250 cm long (the length and size depends on the desired levels of sounds). The bamboo is harvested when it is about 12 months old and left to dry for a few weeks. The Khene maker or "Khene expert" would use a small steel rod to pierce a hole in the knots inside the bamboo, then cuts an incision of 10 cm about 2/3 of the length of the bamboo, with a blade or a sharp knife. On this hole, a silver (or mixed silver and copper) little tongue with a triangular cut in the middle is be placed: the size of the triangular cut determine the melody level. The Khene maker will then make a small round hole a the side of the bamboo tubes in such a way that when all the pipes are assembled through a timber console, these round holes would allow the fingers of the Khene player to block or unblock them to vary the sounds.
Always assumed the reeds were made out of the metal from the beginning, you'd have to consult an archaeologist to answer that question perhaps. Can you make a free reed from bamboo or hardwood? I've made monoglot (single piece) reeds for bagpipe drones out of nothing but wood or metal and reed cane for the tongue; these are a cylinder with its inside bored out and a lay filed into the top at an angle, like a little organ pipe, if you're familiar with the reed variety of those. Seems like you could do the same with a free reed but a metal tongue would be much more robust of course.
For reference:
An Annotated Catalogue of Historic European Free-Reed lnstruments by Stephen Chambers. The aleoinas which were the first production freed reeds in Europe were more like pitch pipes than anything playable though. Dunno what they were keying off of, pardon the pun.