On the very same trip where he brought back the Cambodian Khloy, my friend also found the legendary vietnamese jaw harp, or Ken La in the local language. Made with brass, this might be the stradivarius of the jaw harp world, producing a sound so loud that it doesn't really need to be put into one's mouth to be audible.
I put this Ken La head to head against the local (for me, local means Sundanese) jaw harp, known as Karinding, which is made from bambo. I recorded both with the same setting, but I have to play the ken la slightly further from the mic as it drives my mic of the scale on this setting. Of course, bamboo produces a much sweeter sound, and it is much safer to put into one's mouth! However, in the jaw harp world (which is a very quiet instrument), loudness is everything, so a lot of player are willing to risk their tongue and lips to play the metal jaw harp.
Listen to the Karinding here:
and to the Ken La:
The craftmanship is quite extraordinary fur such a simple instrument, and it comes with a very nice, decorated carrying case. You can see from the 1st picture the side by side comparison of the vietnamese Ken La and the Indonesian (Sundanese) Karinding, with 100 Rupiah and US Quarter for scale. The 2nd picture shows the brass tongue of the Ken La.